High-intensity exercise training induces morphological and biochemical changes in skeletal muscle

Skeletal muscle shows an elevated plasticity and can adapt its metabolic and contractile properties in response to a variety of stimuli such as physical exercise. This implies a series of biochemical and morphological changes in the recruited muscle, in order to produce the more appropriate functional response dependent on the specific stimulation. To determine the effective role of physical exercise in the muscle plasticity, in the present study we investigated the effect of two different exercise protocols on fiber composition and metabolism of two specific muscles of mice: the quadriceps -a fast-twitch muscle- and the gastrocnemius -a typical slow-twitch muscle. Mice were run daily on a motorized treadmill for 8 weeks, at a velocity corresponding to 60% (low-intensity exercise) or 90% (high-intensity exercise) of the maximal running velocity previously determined by an incremental exercise test. We found that at the end of training the body weight was significantly increased in highintensity exercise mice (18.2 ± 1.4 %) compared to low-intensity exercise (8.7 ± 0.6 %) and control (12.7 ± 0.5 %) groups, and it was lesser in low-intensity exercise mice compared to controls. In contrast, the food intake of both exercise training mice was greater compared to control group. Whereas low-intensity exercise mice, despite consumed significantly more food compared to control mice, increased the weight lesser, the weight increase of high-intensity exercise mice, that consumed significantly more food compared to other experimental groups, was significantly greater. These effects were accompanied by a progressive reduction in blood lactate levels at the end of training in both the exercised mice compared with controls; in particular, blood lactate levels after highintensity exercise were significantly lower than those measured in low-intensity exercise mice. Moreover, in the present study we demonstrated that high-intensity exercise training produced a significant increase in the expression of mitochondrial complex enzymes (significant for the enzymes corresponding to the Complex IV, II and I of mitochondrial chain) both in gastrocnemius and quadriceps muscle, compared with controls. These changes were associated with an increase in the amount of slow fibers in both these muscle of high-intensity exercise mice. No changing in the expression of mitochondrial enzymes and in the percentage of slow fibers were found in low-intensity exercise mice

A weak lensing analysis of the PLCK G100.2-30.4 cluster

We present a mass estimate of the Planck-discovered cluster PLCK G100.2-30.4, derived from a weak lensing analysis of deep SUBARU griz images. We perform a careful selection of the background galaxies using the multi-band imaging data, and undertake the weak lensing analysis on the deep (1hr) r-band image. The shape measurement is based on the KSB algorithm; we adopt the PSFex software to model the Point Spread Function (PSF) across the field and correct for this in the shape measurement. The weak lensing analysis is validated through extensive image simulations. We compare the resulting weak lensing mass profile and total mass estimate to those obtained from our re-analysis of XMM-Newton observations, derived under the hypothesis of hydrostatic equilibrium. The total integrated mass profiles are in remarkably good agreement, agreeing within 1$\sigma$ across their common radial range. A mass $M_{500} \sim 7 \times 10^{14} M_\odot$ is derived for the cluster from our weak lensing analysis. Comparing this value to that obtained from our reanalysis of XMM-Newton data, we obtain a bias factor of (1-b) = 0.8 $\pm$ 0.1. This is compatible within 1$\sigma$ with the value of (1-b) obtained by Planck Collaboration XXIV from their calibration of the bias factor using newly-available weak lensing reconstructed masses.Comment: 11 pages, 12 figures, accepted for publication on Astronomy & Astrophysics; updates in affiliation

VIP: An Experiment to Search for a Violation of the Pauli Exclusion Principle

The Pauli Exclusion Principle is a basic principle of Quantum Mechanics, and its validity has never been seriously challenged. However, given its fundamental standing, it is very important to check it as thoroughly as possible. Here we describe the VIP (VIolation of the Pauli exclusion principle) experiment, an improved version of the Ramberg and Snow experiment (E. Ramberg and G. Snow, {\it Phys. Lett. B} {\bf 238}, 438 (1990)); VIP has just completed the installation at the Gran Sasso underground laboratory, and aims to test the Pauli Exclusion Principle for electrons with unprecedented accuracy, down to $\beta^2/2 \approx 10^{-30} - 10^{-31}$. We report preliminary experimental results and briefly discuss some of the implications of a possible violation.Comment: Plenary talk presented by E. Milotti at Meson 2006, Cracow, 9-13 June 200

New experimental limit on the Pauli Exclusion Principle violation by electrons

The Pauli Exclusion Principle (PEP) is one of the basic principles of modern physics and, even if there are no compelling reasons to doubt its validity, it is still debated today because an intuitive, elementary explanation is still missing, and because of its unique stand among the basic symmetries of physics. The present paper reports a new limit on the probability that PEP is violated by electrons, in a search for a shifted K$_\alpha$ line in copper: the presence of this line in the soft X-ray copper fluorescence would signal a transition to a ground state already occupied by 2 electrons. The obtained value, ${1/2} \beta^{2} \leq 4.5\times 10^{-28}$, improves the existing limit by almost two orders of magnitude.Comment: submitted to Phys. Lett.

X-ray characterisation of the massive galaxy clusterClG-J104803.7+313843 at z=0.76 with XMM-Newton

We present the characterisation of the massive cluster ClG-J$104803.7+313843$ at $z=0.76$ performed using a serendipitous XMM-Newton observation. High redshift and massive objects represent an ideal laboratory to benchmark our understanding of how cluster form and assembly formation driven mainly by gravity.Leveraging the high throughput of XMM-Newton we were firstly able to determine the redshift of the object, shedding light on ambiguous photometric redshift associations. We investigated the morphology of this cluster which shows signs of merging activities in the outskirts and a flat core. We also measured the radial density profile up to $R_{500}$. With these quantities in hand, we were able to determine the mass, $M_{500}=5.64^{+0.79}_{-0.62} \times 10^{14}M_{\odot}$, using the YX proxy. This quantity improves previous measurement of the mass of this object by a factor of $\sim 3.5$. The characterisation of one cluster at such mass and redshift regime is fundamental as these objects are intrinsically rare, the number of objects discovered so far being less than $\sim 25$. Our study highlights the importance of using X-ray observations in combination with ancillary multi-wavelength data to improve our understanding of high-z and massive clustersComment: Submitted to A&

New experimental limit on Pauli Exclusion Principle violation by electrons (the VIP experiment)

The Pauli Exclusion Principle is one of the basic principles of modern physics and is at the very basis of our understanding of matter: thus it is fundamental importance to test the limits of its validity. Here we present the VIP (Violation of the Pauli Exclusion Principle) experiment, where we search for anomalous X-rays emitted by copper atoms in a conductor: any detection of these anomalous X-rays would mark a Pauli-forbidden transition. ] VIP is currently taking data at the Gran Sasso underground laboratories, and its scientific goal is to improve by at least four orders of magnitude the previous limit on the probability of Pauli violating transitions, bringing it into the 10**-29 - 10**-30 region. First experimental results, together with future plans, are presented.Comment: To appear in proceedings of the XLVI International Winter Meeting on Nuclear Physics, Bormio, Italy, January 20-26, 200

High-intensity exercise training induces morphological and biochemical changes in skeletal muscles

IN THE PRESENT STUDY WE INVESTIGATED THE EFFECT OF TWO DIFFERENT EXERCISE PROTOCOLS ON FIBRE COMPOSITION AND METABOLISM OF TWO SPECIFIC MUSCLES OF MICE: the quadriceps and the gastrocnemius. Mice were run daily on a motorized treadmill, at a velocity corresponding to 60% or 90% of the maximal running velocity. Blood lactate and body weight were measured during exercise training. We found that at the end of training the body weight significantly increased in high-intensity exercise mice compared to the control group (P=0.0268), whereas it decreased in low-intensity exercise mice compared to controls (P=0.30). In contrast, the food intake was greater in both trained mice compared to controls (P < 0.0001 and P < 0.0001 for low-intensity and high-intensity exercise mice, respectively). These effects were accompanied by a progressive reduction in blood lactate levels at the end of training in both the exercised mice compared with controls (P=0.03 and P < 0.0001 for low-intensity and high-intensity exercise mice, respectively); in particular, blood lactate levels after high-intensity exercise were significantly lower than those measured in low-intensity exercise mice (P=0.0044). Immunoblotting analysis demonstrated that high-intensity exercise training produced a significant increase in the expression of mitochondrial enzymes contained within gastrocnemius and quadriceps muscles. These changes were associated with an increase in the amount of slow fibres in both these muscles of high-intensity exercise mice, as revealed by the counts of slow fibres stained with specific antibodies (P < 0.0001 for the gastrocnemius; P=0.0002 for the quadriceps). Our results demonstrate that high-intensity exercise, in addition to metabolic changes consisting of a decrease in blood lactate and body weight, induces an increase in the mitochondrial enzymes and slow fibres in different skeletal muscles of mice, which indicates an exercise-induced increase in the aerobic metabolism

Testing the Pauli Exclusion Principle for Electrons

One of the fundamental rules of nature and a pillar in the foundation of quantum theory and thus of modern physics is represented by the Pauli Exclusion Principle. We know that this principle is extremely well fulfilled due to many observations. Numerous experiments were performed to search for tiny violation of this rule in various systems. The experiment VIP at the Gran Sasso underground laboratory is searching for possible small violations of the Pauli Exclusion Principle for electrons leading to forbidden X-ray transitions in copper atoms. VIP is aiming at a test of the Pauli Exclusion Principle for electrons with high accuracy, down to the level of 10$^{-29}$ - 10$^{-30}$, thus improving the previous limit by 3-4 orders of magnitude. The experimental method, results obtained so far and new developments within VIP2 (follow-up experiment at Gran Sasso, in preparation) to further increase the precision by 2 orders of magnitude will be presented.Comment: Proceedings DISCRETE 2012-Third Symposium on Prospects in the Physics of Discrete Symmetries, Lisbon, December 3-7, 201

High sensitivity tests of the Pauli Exclusion Principle with VIP2

The Pauli Exclusion Principle is one of the most fundamental rules of nature and represents a pillar of modern physics. According to many observations the Pauli Exclusion Principle must be extremely well fulfilled. Nevertheless, numerous experimental investigations were performed to search for a small violation of this principle. The VIP experiment at the Gran Sasso underground laboratory searched for Pauli-forbidden X-ray transitions in copper atoms using the Ramberg-Snow method and obtained the best limit so far. The follow-up experiment VIP2 is designed to reach even higher sensitivity. It aims to improve the limit by VIP by orders of magnitude. The experimental method, comparison of different PEP tests based on different assumptions and the developments for VIP2 are presented.Comment: 6 pages, 3 figures, Proceedings DISCRETE2014 Conferenc

The VIP Experiment

The Pauli Exclusion Principle (PEP) is a basic principle of Quantum Mechanics, and its validity has never been seriously challenged. However, given its importance, it is very important to check it as thoroughly as possible. Here we describe the VIP (Violation of PEP) experiment, an improved version of the Ramberg and Snow experiment (Ramberg and Snow, Phys. Lett. B238 (1990) 438); VIP shall be performed at the Gran Sasso underground laboratories, and aims to test the Pauli Exclusion Principle for electrons with unprecedented accuracy, down to $\frac{\beta^2}{2} \sim 10^{-30}$Comment: 7 pages, 5 figures, PDF only, presented by Edoardo Milotti to the conference "Quantum Theory: reconsideration of foundations-3", Vaxjo (Sweden), June, 6-11 200