Reversals in nature and the nature of reversals

The asymmetric shape of reversals of the Earth's magnetic field indicates a possible connection with relaxation oscillations as they were early discussed by van der Pol. A simple mean-field dynamo model with a spherically symmetric $\alpha$ coefficient is analysed with view on this similarity, and a comparison of the time series and the phase space trajectories with those of paleomagnetic measurements is carried out. For highly supercritical dynamos a very good agreement with the data is achieved. Deviations of numerical reversal sequences from Poisson statistics are analysed and compared with paleomagnetic data. The role of the inner core is discussed in a spectral theoretical context and arguments and numerical evidence is compiled that the growth of the inner core might be important for the long term changes of the reversal rate and the occurrence of superchrons.Comment: 24 pages, 12 figure

Real-time evaluation of longitudinal peak systolic strain (speckle tracking measurement) in left and right ventricles of athletes

<p>Abstract</p> <p>Background</p> <p>Strain, and particularly Longitudinal Peak Systolic Strain (LPSS), plays a role in investigating the segmental and overall contractility of the heart which is a particularly interesting feature in athletes in whom regular training determines several morphological and functional modifications in both the ventricles, that normally work at different loads. Speckle tracking techniques assess the LPSS of LV and RV from B-mode imaging in real time, with uniform accuracy in all segments, and can verify the possible dissimilar segmental contributions of the two chambers to overall myocardial contraction. The aim of the study is to quantify the LPSS in real time in both the ventricles in order to estimate any possible different deformation properties in them during a systolic period.</p> <p>Methods</p> <p>32 subjects (20 athletes and 18 controls) were submitted to a standard echocardiographic examination at rest and after a Hand Grip (HG) stress. From a four-chamber-view image, the LPSS parameter was measured with Speckle Tracking analysis in the basal and medium-apical segments of the two ventricles, at rest and after HG.</p> <p>Results</p> <p>In both athletes and controls, LPSS values were significantly higher in the RV of athletes (RV LPSS ^{medium-apical}-23.87 ± 4.94; ^{basalfreewall}-25.04 ± 4.12 at rest) and controls (RV LPSS^{medium-apical}-25.21 ± 4.97; ^{basalfreewall}-28.69 ± 4.62 at rest) than in the LV of both (athletes LV LPSS ^{medium-apical}-18.14 ± 4.16; ^{basallateralwall}-16.05 ± 12.32; controls ^{medium-apical}-18.81 ± 2.64; ^{basallateralwall}-19.74 ± 3.84) With the HG test a significant enhancement of the LPSS(with P < .05) in the medium-apical segments of LV and RV was evident, but only in athletes; there was no modification of the standard echo-parameters in either group.</p> <p>Conclusion</p> <p>ST analysis is an easy method for investigating the contractility of the RV through deformation parameters, showing greater involvement of the RV than LV at rest. In athletes only, after isometric stress the two ventricles show particular myocardial deformation properties of the regions around the apex where the curvature of the wall is more marked. The clinical application of this new approach in athletes and normal subjects requires further investigation.</p

Use of infrared thermography (IRT) in equine assisted interventions: physiological aspects

Infrared imaging thermography (IRT) is a technique widely used in wildlife studies and the assessment of animal welfare is among its fields of application. The heat emitted from superficial capillaries changes as blood flow is under control of the autonomic nervous system. For this reason, cutaneous temperature on selected areas can be considered as a good indicator of the health status and welfare of a particular individual. These changes in heat emitted can be quantified using IRT. The system consists of an infrared camera FLIR A65 (640 512 pixel, uncooled microbolometer detector, thermal sensitivity 0.05 \ub0C) with a 7\ub0 and 13\ub0 angle of view germanium tele lenses and a dedicated laptop. In the case of chimpanzees\u2019 studies, most of the available data derive from subjects kept in small enclosures, with little ecological validity. The aim of this research was to develop an infrared method allowing the acquisition of thermographic videos and images of animals at long distance. The system was tested on a group of eleven chimpanzees, in semi-natural conditions, housed at Parco Natura Viva in Bussolengo (Verona). The study ran between April and December 2016. Images and videos were shot at distance greater than 10 meters, during the everyday chimpanzees\u2019 life. The accuracy and repeatability of measurements was that typically reserved to the image acquisition with closer subjects at indoor conditions. Through this system it was possible to detect temperature variations in face layers by distinguishing the facial features of the subject. Thus, despite the distance from the animals, thanks to the good resolution of the system, the cutaneous temperatures were detected. In conclusion, IRT could be able to non-invasively detect different autonomic responses of the chimpanzees to different situations, suggesting that this system could be a valuable tool to study the chimpanzee\u2019s behavior and welfare at long distance

Liquefied sites of the 2012 Emilia earthquake: a comprehensive database of the geological and geotechnical features (Quaternary alluvial Po plain, Italy)

This paper presents a comprehensive geological and geotechnical study of the whole area affected by liquefaction following the 2012 Emilia earthquakes, including all the available information from the field reconnaissance surveys, in situ tests, and laboratory analyses. The compilation was performed at 120 liquefied sites to verify and validate the reliability of liquefaction charts in alluvial sediments, and to assess liquefaction induced by the 2012 seismic sequence in the Emilia plain. The results reveal a wide range of grain sizes (from clean sands to sandy silts) and compositional characteristics (quartz-rich to litharenitic) in the 2012 ejecta, and show a strong relationship between the liquefaction and stratigraphic architecture of the subsurface. The availability of in situ tests at the liquefied sites makes it possible to verify and validate the reliability of the liquefaction charts in alluvial sediments with respect to the real observations. For the analyzed Emilia case studies, the use of non-liquefiable crust provides better estimations of the liquefaction manifestations when coupled with the thickness of the liquefiable layer rather than with the liquefaction potential index. Altogether, this work makes available to the international scientific community a consistent liquefaction database for in-depth earthquake studies

Congou tea drinking and oesophageal cancer in South China

The study from a large hospital-based case–control for 1248 cases with oesophageal cancer and the same number of controls in South China showed that Congou, a grade of Chinese black tea, may protect against cancers of the oesophagus and reduce the risk of a combination of alcohol drinking and smoking (especially smoking), regardless of temperature when drinking

Adding diphenyl diselenide in the diets of quails improves the quality of meat.

Abstract: Diphenyl diselenide (Ph2Se2) is an organic selenium compound that is known for its antioxidant characteristics. Thus, the aim of this study was to evaluate whether Ph2Se2 in quail (Coturnix japonica) diets influences the oxidative/antioxidant status and meat quality. Materials and methods. Four diets (0; 0.3; 0.6; 0.9 ppm Ph2Se2) were provided to 56 male quails (Coturnix japonica) distributed in a completely randomized design with 14 repetitions in order to check whether (PhSe)2 would change their blood and tissue oxidative/antioxidant status, which would lead to an improvement in the meat quality. Results. Adding Ph2Se2 in diets led to increased antioxidant activity of enzymes such as catalase, superoxide dismutase, and glutathione peroxidase, which consequently reduced oxidative levels in blood and tissues. Besides that, we observed an improvement in the quail meat quality; in other words, we observed an increased ability to hold water, a reduction in water loss from cooking, and reduced intensity of the yellow color in the breasts of birds that were fed with Ph2Se2. Conclusions. Therefore, we concluded that the antioxidant defense improvement in tissues that was provided by Ph2Se2 has a beneficial effect on meat quality. Resumen: El diseleniuro de difenilo (Ph2Se2) es un compuesto de selenio orgánico que es conocido por sus características antioxidantes. Por lo tanto, el objetivo de este estudio fue evaluar si Ph2Se2 en las dietas de codorniz (Coturnix japonica) influye en el estado oxidativo/antioxidante y la calidad de la carne. Materiales y métodos. Se proporcionaron cuatro dietas (0; 0.3; 0.6; 0.9 ppm Ph2Se2) a 56 codornices machos (Coturnix japonica) distribuidas en un diseño completamente aleatorizado con 14 repeticiones para verificar si Ph2Se2 cambiaría su sangre y tejido oxidativo/antioxidante, estado, lo que llevaría a una mejora en la calidad de la carne. Resultados. La adición de Ph2Se2 en las dietas provocó un aumento de la actividad antioxidante de enzimas como la catalasa, la superóxido dismutasa y la glutatión peroxidasa, lo que redujo los niveles de oxidación en la sangre y los tejidos. Además de eso, observamos una mejora en la calidad de la carne de codorniz; en otras palabras, observamos una mayor capacidad para retener agua, una reducción en la pérdida de agua debido a la cocción y una menor intensidad del color amarillo en las mamas de las aves que fueron alimentadas con Ph2Se2. Conclusiones. Por lo tanto, concluimos que la mejora de la defensa antioxidante en los tejidos proporcionada por Ph2Se2 tiene un efecto beneficioso sobre la calidad de la carne