3,685 research outputs found

    Dim Light Exposure or Melatonin Ingestion Lowers a Type 2 Diabetic\u27s Blood Glucose Removal Rate: A Single Case

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    International Journal of Exercise Science 12(2): 1161-1168, 2019. The purpose of this case study isto compare a Type 2 diabetic\u27s postprandial glucoregulatory ability under two different room lighting conditions. The subject was a 56-year-old physically active male with well controlled blood glucose levels (HbA1c ≀ 6% for 5 y) from a combination of diet, exercise, and medication. Two hours post evening meal (380 kcal, 18 g fat, 44 g carbohydrate, 12 g protein), a 45 g carbohydrate challenge was given, and blood glucose was measured every 30 minutes for 2.5 hours under three conditions: dim light (\u3c50 lux) (DL), bright light (\u3e40000 lux) (BL), and bright light plus 6 mg melatonin (BLM). Each condition was repeated 3 times over a period of 6 months with each trial a minimum of seven days apart. The area under the average glucose concentration vs.time plot was different between the three conditions (BL = 909 +76; DL = 1078 +106; and BLM = 1130 +45 mmol∙min∙l-1). Visual inspection of the average blood glucose vs.time plot suggested that DL and BLM displayed very similar patterns and magnitude, with both DL and BLM having the blood glucose concentrations at each time point that are noticeably greater than BL. Additionally, the average (± standard deviation) blood glucose concentrations for DL (8.8 ± 0.9 mmol∙l-1) and BLM (9.1 ± 1.1 mmol∙l-1) were respectively 18% and 22% greater than BL (7.5 ± 0.5 mmol∙l-1). Melatonin and/or dim light can reduce a Type 2 diabetic\u27s glucoregulatory ability

    Effect of 12 weeks of periodized resistance training upon total plasma adiponectin concentration in healthy young men

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    © 2015 National Strength and Conditioning Association. The effects of resistance training on adiponectin have thus far yielded equivocal results. However, the effect of periodized resistance training on plasma adiponectin in offspring of type 2 diabetic and nondiabetic (ND) parents (first-degree family history) has yet to be determined. Untrained healthy young men with and without a first-degree family history of type 2 diabetes were assigned to an exercise intervention group (E) or an active control group (C). The E group performed a 12-week periodized resistance training program, whereas the C group did not participate in any structured exercise program. Fasting plasma samples were obtained pre- and posttraining. Total plasma adiponectin changed significantly in the E group (33.7 ± 14.7%, p 0.025) but not in the C group (10.8 ± 19.2%). Offspring of type 2 diabetic parents subjects had significantly greater improvements in plasma adiponectin (69.3 ± 34.8%) compared with ND subjects (-3.2 ± 29.9%, p 0.046). Regular aerobic exercise was significantly correlated with average plasma adiponectin (r 0.32), whereas first-degree family history of type 2 diabetes (r -0.58) and decreases in body fat percentage (r -0.77) were inversely correlated with average plasma adiponectin. Periodized high-intensity resistance training seems to increase plasma adiponectin, particularly in individuals with a first-degree family history of type 2 diabetes or those who experience a significant loss of fat mass. The direct correlation between regular aerobic exercise and adiponectin further suggests that a combination of aerobic and resistance training yields greater improvements in plasma adiponectin compared with resistance training alone

    The impact of constructive operating lease capitalisation on key accounting ratios

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    Current UK lease accounting regulation does not require operating leases to be capitalised in the accounts of lessees, although this is likely to change with the publication of FRS 5. This study conducts a prospective analysis of the effects of such a change. The potential magnitude of the impact of lease capitalisation upon individual users' decisions, market valuations, company cash flows, and managers' behaviour can be indicated by the effect on key accounting ratios, which are employed in decision-making and in financial contracts. The capitalised value of operating leases is estimated using a method similar to that suggested by Imhoff, Lipe and Wright (1991), adapted for the UK accounting and tax environment, and developed to incorporate company-specific assumptions. Results for 1994 for a random sample of 300 listed UK companies show that, on average, the unrecorded long-term liability represented 39% of reported long-term debt, while the unrecorded asset represented 6% of total assets. Capitalisation had a significant impact (at the 1% level) on six of the nine selected ratios (profit margin, return on assets, asset turnover, and three measures of gearing). Moreover, the Spearman rank correlation between each ratio before and after capitalisation revealed that the ranking of companies changed markedly for gearing measures in particular. There were significant inter-industry variations, with the services sector experiencing the greatest impact. An analysis of the impact of capitalisation over the five-year period from 1990 to 1994 showed that capitalisation had the greatest impact during the trough of the recession. Results were shown to be robust with respect to key assumptions of the capitalisation method. These findings contribute to the assessment of the economic consequences of a policy change requiring operating lease capitalisation. Significant changes in the magnitude of key accounting ratios and a major shift in company performance rankings suggest that interested parties' decisions and company cash flows are likely to be affected

    A Pre-Exercise Dose of Melatonin Can Alter Substrate Use During Exercise

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    International Journal of Exercise Science 10(7): 1029-1037, 2017. Notwithstanding the lack of exercise research, several reviews have championed the use of melatonin to combat metabolic syndrome. Therefore, this study compared substrate utilization during a 30-minute (min) graded exercise protocol following the ingestion of either 6 mg melatonin (M) or a placebo (P). Participants (12 women, 12 men) performed stages 1-5 of the Naughton graded exercise protocol (6 min per stage). The protocol was repeated 4 times (2x M, 2x P) at the same time of day with one week separating each session. Expired gases were monitored, VO2 and respiratory exchange ratio (RER) output was provided every 30s. Total, carbohydrate (CHO), and fat energy expenditures were obtained from the RER values using the formulae of Lusk. The VO2 at which CHO accounted for 50% of the total caloric expenditure was calculated by a VO2: RER regression line. Additionally, the energy derived was calculated by multiplying VO2 and the respective energy expenditures. Then, the total, CHO, and fat energies consumed during the 30 min of exercise were determined by calculating the area under the kJ/min: time curve using the trapezoid rule. The final data for the two similar trials were averaged and a paired-T test was used for statistical comparison. The average VO2 for 50% CHO usage was significantly lower following M (0.84 ± 0.54 l·min-1) than after P (1.21 ± 0.52 l·min-1). Also, average CHO kJ for M (627 ± 284) was significantly (p \u3c 0.004) greater than P (504 ± 228), and accounted for a significantly greater contribution of total kJ consumed (M = 68% ±15 vs. P = 61% ± 18). Ingestion of melatonin 30 min prior to an aerobic exercise bout elevates CHO use during exercise

    Electroweak Bubble Nucleation, Nonperturbatively

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    We present a lattice method to compute bubble nucleation rates at radiatively induced first order phase transitions, in high temperature, weakly coupled field theories, nonperturbatively. A generalization of Langer's approach, it makes no recourse to saddle point expansions and includes completely the dynamical prefactor. We test the technique by applying it to the electroweak phase transition in the minimal standard model, at an unphysically small Higgs mass which gives a reasonably strong phase transition (lambda/g^2 =0.036, which corresponds to m(Higgs)/m(W) = 0.54 at tree level but does not correspond to a positive physical Higgs mass when radiative effects of the top quark are included), and compare the results to older perturbative and other estimates. While two loop perturbation theory slightly under-estimates the strength of the transition measured by the latent heat, it over-estimates the amount of supercooling by a factor of 2.Comment: 48 pages, including 16 figures. Minor revisions and typo fixes, nothing substantial, conclusions essentially unchange

    How fast can the wall move? A study of the electroweak phase transition dynamics

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    We consider the dynamics of bubble growth in the Minimal Standard Model at the electroweak phase transition and determine the shape and the velocity of the phase boundary, or bubble wall. We show that in the semi-classical approximation the friction on the wall arises from the deviation of massive particle populations from thermal equilibrium. We treat these with Boltzmann equations in a fluid approximation. This approximation is reasonable for the top quarks and the light species while it underestimates the friction from the infrared WW bosons and Higgs particles. We use the two-loop finite temperature effective potential and find a subsonic bubble wall for the whole range of Higgs masses 0<mH<900<m_H<90GeV. The result is weakly dependent on mHm_H: the wall velocity vwv_w falls in the range 0.36<vw<0.440.36<v_w<0.44, while the wall thickness is in the range 29>LT>2329> L T > 23 . The wall is thicker than the phase equilibrium value because out of equilibrium particles exert more friction on the back than on the base of a moving wall. We also consider the effect of an infrared gauge condensate which may exist in the symmetric phase; modelling it simplemindedly, we find that the wall may become supersonic, but not ultrarelativistic.Comment: 42 pages, plain latex, with three figures. Minor editing August 1 (we figured out how to do analytically some integrals we previously did numerically, made corresponding (slight) changes to numerical results, and corrected some typos.

    Hypercharge and the Cosmological Baryon Asymmetry

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    Stringent bounds on baryon and lepton number violating interactions have been derived from the requirement that such interactions, together with electroweak instantons, do not destroy a cosmological baryon asymmetry produced at an extremely high temperature in the big bang. While these bounds apply in specific models, we find that they are generically evaded. In particular, the only requirement for a theory to avoid these bounds is that it contain charged particles which, during a certain cosmological epoch, carry a non-zero hypercharge asymmetry. Hypercharge neutrality of the universe then dictates that the remaining particles must carry a compensating hypercharge density, which is necessarily shared amongst them so as to give a baryon asymmetry. Hence the generation of a hypercharge density in a sector of the theory forces the universe to have a baryon asymmetry.Comment: 12 pages plus 1 Postscript figure available upon request. LBL 3482

    The Singlet Majoron Model with Hidden Scale Invariance

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    We investigate an extension of the Singlet Majoron Model in which the breaking of dilatation symmetry by the mass parameters of the scalar potential is removed by means of a dilaton field. Starting from the one-loop renormalization group improved potential, we discuss the ground state of the theory. The flat direction in the classical potential is lifted by quantum corrections and the true vacua are found. Studying the finite temperature potential, we analyze the cosmological consequences of a Jordan-Brans-Dicke dilaton and show that the lepton number is spontaneously broken after the electroweak phase transition, thus avoiding any constraint coming from the requirement of the preservation of the baryon asymmetry in the early Universe. We also find that, contrary to the Standard Model case, the dilaton cosmology does not impose any upper bound on the scale of the spontaneous breaking of scale invariance.Comment: 22 pages, SISSA-5/93/A and DFPD/93/TH/0

    On the Global Existence of Bohmian Mechanics

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    We show that the particle motion in Bohmian mechanics, given by the solution of an ordinary differential equation, exists globally: For a large class of potentials the singularities of the velocity field and infinity will not be reached in finite time for typical initial values. A substantial part of the analysis is based on the probabilistic significance of the quantum flux. We elucidate the connection between the conditions necessary for global existence and the self-adjointness of the Schr\"odinger Hamiltonian.Comment: 35 pages, LaTe
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