Use of iodine and selenium enriched fodder rations for production of fortified young lamb

The article is devoted to preventive measures to eliminate the problem of dysmicroelementosis in order to increase the productivity of young sheep. The article presents the results of studies of the influence of feeding rations on the growth and development of young sheep of the Edilbaev breed, on the level of their meat productivity and the qualitative characteristics of biologically fortified lamb. Feed additives based on Yoddar-Zn and DAFS-25 were added to the main ration of lambs at the age of four months, once a day, being added into a fodder mixture with concentrates. For the experiment the herd of lambs was divided to four groups of 25 heads each.The changes in live weight at the age of four, five, six and seven months were analyzed, and it was found that at the age of seven months, the absolute average weight gain in the experimental groups varied from 3.45 kg to 4.49 kg, in the control group it was 3.1 kg, while the largest live weight gain was recorded in group III which received both feed additives based on Yoddar-Zn and DAFS-25.There were no significant differences in the parameters of body measurements, with the exception of group III, where the chest circumference increased by 7.2%, and the height of a lamb at the withers increased in average by 8.1%. It was found that group III had the highest meat density coefficient, equal to 3.9, and the cross-sectional area of m. Longissimus dorsi was equal to 13.61 cm2. It was noted that the amount of free amino acids of the lamb group III is 18.8% higher than the meat of the control group. The lamb obtained from the animals of the experimental groups showed a higher protein content and less fat. The ratio of water to protein in all samples was slightly higher than 3.7, which corresponds to the Federa number for meat raw materials. Enriching the rations of the Edilbaevskoy sheep with feed additives Yoddar-Zn and DAFS-25 promotes the stimulation of growth and development of animals, increases the productivity and nutritional value of lamb

First optical validation of a Schwarzschild Couder telescope: the ASTRI SST-2M Cherenkov telescope

The Cherenkov Telescope Array (CTA) represents the most advanced facility designed for Cherenkov Astronomy. ASTRI SST-2M has been developed as a demonstrator for the Small Size Telescope in the context of the upcoming CTA. Its main innovation consists in the optical layout which implements the Schwarzschild-Couder configuration and is fully validated for the first time. The ASTRI SST-2M optical system represents the first qualified example for two mirrors telescope for Cherenkov Astronomy. This configuration permits to (i) maintain a high optical quality across a large FoV (ii) de-magnify the plate scale, (iii) exploit new technological solutions for focal plane sensors. The goal of the paper is to present the optical qualification of the ASTRI SST-2M telescope. The qualification has been obtained measuring the PSF sizes generated in the focal plane at various distance from the optical axis. These values have been compared with the performances expected by design. After an introduction on the Gamma Astronomy from the ground, the optical design and how it has been implemented for ASTRI SST-2M is discussed. Moreover the description of the setup used to qualify the telescope over the full field of view is shown. We report the results of the first--light optical qualification. The required specification of a flat PSF of $\sim 10$ arcmin in a large field of view ~10 deg has been demonstrated. These results validate the design specifications, opening a new scenario for Cherenkov Gamma ray Astronomy and, in particular, for the detection of high energy (5 - 300 TeV) gamma rays and wide-field observations with CTA.Comment: 6 pages, 5 figure

Polarimetric survey of asteroids with the Asiago telescope

We present the first results of an asteroid photo--polarimetry program started at Asiago--Cima Ekar Observatory. The aim of our survey is to estimate diversity in polarimetric properties of asteroids belonging to different taxonomic and dynamical classes. The data were obtained with the polarization analyser placed inside the Faint Object Spectrographic Camera (AFOSC) of the 1.8m telescope. This instrument allows simultaneous measurements of the two first Stokes parameters without any lambda/2 retarding plate. Our survey began in 2002, and up to now we have obtained data on a sample of 36 asteroids; most of them are being investigated with the polarimetric technique for the first time. Combining our data with those already available in literature, we present an estimate of the inversion angle for 7 asteroids in this paper. Furthermore, we present the polarimetric measurements of the rare asteroid classes belonging to the A and D types and a detailed VRI observations at extremely small phase angles of the low albedo asteroid 1021 Flammari

The gravitational mass of Proxima Centauri measured with SPHERE from a microlensing event

Proxima Centauri, our closest stellar neighbour, is a low-mass M5 dwarf orbiting in a triple system. An Earth-mass planet with an 11 day period has been discovered around this star. The star's mass has been estimated only indirectly using a mass-luminosity relation, meaning that large uncertainties affect our knowledge of its properties. To refine the mass estimate, an independent method has been proposed: gravitational microlensing. By taking advantage of the close passage of Proxima Cen in front of two background stars, it is possible to measure the astrometric shift caused by the microlensing effect due to these close encounters and estimate the gravitational mass of the lens (Proxima Cen). Microlensing events occurred in 2014 and 2016 with impact parameters, the closest approach of Proxima Cen to the background star, of 1\farcs6 $\pm$ 0\farcs1 and 0\farcs5 $\pm$ 0\farcs1, respectively. Accurate measurements of the positions of the background stars during the last two years have been obtained with HST/WFC3, and with VLT/SPHERE from the ground. The SPHERE campaign started on March 2015, and continued for more than two years, covering 9 epochs. The parameters of Proxima Centauri's motion on the sky, along with the pixel scale, true North, and centering of the instrument detector were readjusted for each epoch using the background stars visible in the IRDIS field of view. The experiment has been successful and the astrometric shift caused by the microlensing effect has been measured for the second event in 2016. We used this measurement to derive a mass of 0.150$^{\textrm{+}0.062}_{-0.051}$ (an error of $\sim$ 40\%) \MSun for Proxima Centauri acting as a lens. This is the first and the only currently possible measurement of the gravitational mass of Proxima Centauri.Comment: 10 pages, 6 figures, accepted by MNRA