3,163 research outputs found
Stability of selected enzymes in saliva of pigs under different storage conditions : a pilot study
Stability of α-amylase (α-A), butyrylcholinesterase (BChE), lipase, adenosine deaminase (ADA) and total esterase activity (TEA) in two pools of porcine saliva was studied after 1 and 4 days at 4°C, and after 30, 90 and 360 days at −20° and −80°C. At 4°C, BChE, lipase and TEA were stable less than 1 day, α-A less than 4 days and ADA for up to 4 days. At −20°C, BChE and TEA were stable less than 30 days, α-A and lipase less than 90 days and ADA up to 360 days. At −80°C, TEA was stable less than 30 days, α-A and lipase less than 360 days, and BChE and ADA for up to 360 days
Active commuting is associated with a lower risk of obesity, diabetes and metabolic syndrome in Chilean adults
Background:
There is limited evidence on how active commuting is associated with health benefits in developing countries. The aim of this study therefore was to investigate the associations between active commuting and markers of adiposity and cardiometabolic risk in the Chilean adult population.
Methods:
In total, 5157 participants from the Chilean National Health Survey 2009–10 were included in this cross-sectional study. Active commuting was measured using the Global Physical Activity Questionnaire (GPAQ v2). Body mass index (BMI) and waist circumference (WC) were measured and used to define obesity and central obesity. Type 2 diabetes (T2D) and metabolic syndrome were determined using WHO and updated ATPIII-NCEP criteria, respectively.
Results:
The main finding of this study is that a 30 min increase in active commuting is associated with lower odds for BMI > 25.0 kg m−2 (0.93 [95% CI: 0.88–0.98, P = 0.010]). Similarly, the odds for central obesity was 0.87 [0.82–0.92, P < 0.0001]. Similar associations were found for T2D (0.81 [0.75–0.88], P < 0.0001) and metabolic syndrome (OR: 0.86 [0.80–0.92], P < 0.0001).
Conclusion:
Our findings show that active commuting is associated with lower adiposity and a healthier metabolic profile including lower risk for obesity, diabetes and metabolic syndrome
Chromomagnetic Dipole Moment of the Top Quark Revisited
We study the complete one-loop contributions to the chromagnetic dipole
moment of the top quark in the Standard Model, two Higgs doublet
models, topcolor assited technicolor models (TC2), 331 models and extended
models with a single extra dimension. We find that the SM predicts
and that the predictions of the other models are also
consitent with the constraints imposed on by low-energy
precision measurements.Comment: 20 pages, 5 figures, Updat
Factorizing the time evolution operator
There is a widespread belief in the quantum physical community, and in
textbooks used to teach Quantum Mechanics, that it is a difficult task to apply
the time evolution operator Exp{-itH/h} on an initial wave function. That is to
say, because the hamiltonian operator generally is the sum of two operators,
then it is a difficult task to apply the time evolution operator on an initial
wave function f(x,0), for it implies to apply terms operators like (a+b)^n. A
possible solution of this problem is to factorize the time evolution operator
and then apply successively the individual exponential operator on the initial
wave function. However, the exponential operator does not directly factorize,
i. e. Exp{a+b} is not equal to Exp{a}Exp{b}. In this work we present a useful
procedure for factorizing the time evolution operator when the argument of the
exponential is a sum of two operators, which obey specific commutation
relations. Then, we apply the exponential operator as an evolution operator for
the case of elementary unidimensional potentials, like the particle subject to
a constant force and the harmonic oscillator. Also, we argue about an apparent
paradox concerning the time evolution operator and non-spreading wave packets
addressed previously in the literature.Comment: 24 pages; added references; one figure change
Joint effect of physical activity and sedentary behaviour on cardiovascular risk factors in Chilean adults
Background:
To investigate the associations between combined categories of moderate-to-vigorous physical activity (MVPA) and sedentary behaviour (SB) with markers of adiposity and cardiovascular risk in adults.
Methods:
Overall, 5040 participants (mean age 46.4 years and 59.3% women) from the cross-sectional Chilean National Health Survey 2009–2010 were included in this study. MVPA and SB were measured using the Global Physical Activity questionnaire. Four categories were computed using MVPA- and SB-specific cut-offs (‘High-SB & Active’, ‘Low-SB & Active’, ‘High-SB & Inactive’ and ‘Low-SB & Inactive’).
Results:
Compared to the reference group (‘High-SB & Inactive’), those in ‘High-SB & Active’ and ‘Low-SB & Active’ were less likely to have an obese BMI (OR: 0.67 [0.54; 0.85], P = 0.0001 and 0.74 [0.59; 0.92] P = 0.0007, respectively) and less likely to have metabolic syndrome (OR: 0.63 [0.49; 0.82], P < 0.0001 and 0.72 [0.57; 0.91], P = 0.007), central obesity (OR: 0.79 [0.65; 0.96], P = 0.016 and 0.71 [0.59; 0.84], P < 0.0001), diabetes (OR: 0.45 [0.35; 0.59], P < 0.0001 and 0.44 [0.34; 0.56], P < 0.0001) and hypertension (OR: 0.52 [0.43; 0.63], P < 0.0001 and 0.60 [0.50; 0.72], P < 0.0001), respectively.
Conclusions:
Being physically active and spending less time in SBs was associated with lower adiposity and improvements in cardiovascular risk factors
Dilepton azimuthal correlations in tt production
The dilepton azimuthal correlation, namely the difference phi between the azimuthal
angles of the positive and negative charged lepton in the laboratory frame, provides
a stringent test of the spin correlation in tt production at the Large Hadron Collider. We
introduce a parameterisation of the differential cross section dalpha=dphi in terms of a Fourier
series and show that the third-order expansion provides a su ciently accurate approximation.
This expansion can be considered as a `bridge' between theory and data, making it
very simple to cast predictions in the Standard Model (SM) and beyond, and to report
measurements, without the need to provide the numbers for the whole binned distribution.
We show its application by giving predictions for the coeffcients in the presence of
(i) an anomalous top chromomagnetic dipole moment; (ii) an anomalous tbW interaction.
The methods presented greatly facilitate the study of this angular distribution, which is of
special interest given the 3:2(3:7) deviation from the SM next-to-leading order prediction
found by the ATLAS collaboration in Run 2 data.This work has been supported by MINECO Project FPA 2013-47836-C3-2-P (including
ERDF)
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