Medical Supervision of Young Female Athletes Training in Complex Coordinational Sports

This article proposes simple medical criteria that can be used by trainers and others for effective medical supervision of young female athletes. METHODS: The cross-sectional, age-stratified study compared girls 10-17 years of age involved in intensive training in gymnastic floor exercises, trampoline, or badminton. Each sport and/or control group was represented by 40-45 girls. Data included medical history, morphometric variables and observation of biological development. RESULTS: Gymnasts started training earliest (approximately 5-years-old) and trained most intensely (18-20 h/wk), followed by trampolinists and then badmintonists. Height, weight, body mass index, and % body fat were reduced in athletes, with gymnasts showing the greatest reduction. Athletes showed higher ratios of leg length to height and shoulder width/hip width, and smaller pelvic size compared to height. The average age of menarche of gymnasts was 13.8 (1.6 year later than controls). Delays of biological development of more than 2 years were common in athletes, and some gymnasts showed more than a 4-year delay. These delays were related to morphometric indicators of hormonal imbalance and to low body fat. Gymnasts had more childhood diseases, with an infection index of 2.8 compared to 1.1 for the control group, and had a higher level of chronic ENT problems. CONCLUSIONS: Trainers need to protect the health of athletes. During the course of training, anamneses, delayed menarche and other signs of delayed biological development must be monitored. Morphometric measures and indicators of biological development are proposed to provide simple criteria important in protecting the athletes\u27 health

Funneling Light Through a Subwavelength Aperture with Epsilon-Near-Zero Materials

Integration of the next generation of photonic structures with electronic and optical on-chip components requires the development of effective methods for confining and controlling light in subwavelength volumes. Several techniques enabling light coupling to sub-wavelength objects have recently been proposed, including grating-, and composite-based solutions. However, experi-mental realization of these couplers involves complex fabrication with \sim 10nm resolution in three dimensions. One promising alternative to complex coupling structures involves materials with vanishingly small dielectric permittivity, also known as epsilon-near-zero (ENZ) materials. In contrast to the previously referenced approaches, a single at layer of ENZ-material is expected to provide effcient coupling between free-space radiation and sub-wavelength guiding structures. Here we report the first direct observation of bulk-ENZ-enhanced transmission through a subwavelength slit, accompanied by a theoretical study of this phenomenon. Our study opens the door to multiple practical applications of ENZ materials and ENZ-based photonic systems

Эффективность использования экстракта крапивы двудомной при выращивании цыплят-бройлеров

Currently, agricultural specialists have a great interest in poultry feed additives that can become an alternative to antibiotics. Medicinal plants are a source of a wide range of biologically active compounds that have, among others, antimicrobial effects. The authors believe that a comprehensive evaluation of the efficacy of their use under production conditions should be carried out. This evaluation is necessary to obtain a fuller picture of the potential use of various forms of medicinal plants, in particular their extracts, in poultry production. The authors studied the effect of feeding different doses of water-ethanol extract of nettle (Urtica dioica L.) on growth, carcass quality, safety and chemical composition of meat of broiler chickens of ISA F15 cross from one day old to 40 days old. The experiment was conducted in an industrial poultry farm of Kuzbass, where a control group and five experimental groups of 35-day-old chickens were selected by the method of similar groups. Throughout the experiment, the chickens of the control group were fed complete feed according to the phases of rearing, and the birds of the experimental groups were fed additional nettle extract in different doses. Feeding broiler chickens with nettle extract at the doses of 5, 10, 15 and 20 mg/kg body weight increased the intensity of their growth by 0,4-1,4% and reduced feed conversion by 0,6-2,3%. High survival was noted in the groups which received the extract at doses of 5, 10, 20 mg/kg body weight. When nettle extract is added to complete feed for broiler chickens, the tendency to increase the carcass slaughter yield by 0,3-0,75% in groups 2, 3, and 4 of experimental and the caloric content of poultry meat by 0,8-6,6% in all experimental groups is established. Based on the results of the poultry meat production efficiency index evaluation, the authors suggest including nettle extract at a dose of 10 mg/kg body weight in the composition of complete feed when raising broiler chickens in order to increase the level of profitability.В настоящее время специалисты АПК испытывают большой интерес к кормовым добавкам для птицеводства, способным стать альтернативой антибиотикам. Лекарственные растения являются источником широкого спектра биологически активных соединений, обладающих, в том числе, антимикробными эффектами. Для получения более полной картины потенциального использования различных форм лекарственных растений, в частности их экстрактов, в птицеводстве, необходимо проводить всестороннюю оценку эффективности их использования в производственных условиях. Мы изучили влияние скармливания различных доз водно-этанольного экстракта крапивы двудомной (Urtica dioica L.) на показатели роста, качества тушек, сохранность и химический состав мяса цыплят-бройлеров кросса ISA F15 с суточного до 40-дневного возраста. Эксперимент проводили в условиях промышленной птицефабрики Кузбасса, где по методу аналогичных групп были подобраны контрольная и пять опытных групп суточных цыплят по 35 голов. В течение всего опыта цыплятам контрольной группы скармливали полнорационные комбикорма согласно фазам выращивания, а птице опытных групп – дополнительно экстракт крапивы двудомной в различных дозах. Скармливание цыплятамбройлерам экстракта крапивы двудомной в дозах 5, 10, 15 и 20 мг/кг массы тела способствовало повышению интенсивности их роста на 0,4–1,4% и снижению конверсии корма на 0,6–2,3%. Высокая сохранность отмечена в группах, которые получали экстракт в дозах 5, 10, 20 мг/кг массы тела. При введении экстракта крапивы двудомной в полнорационные комбикорма для цыплят-бройлеров установлены тенденции к повышению убойного выхода тушек на 0,3–0,75% во 2, 3, и 4-й опытных группах и калорийности мяса птицы на 0,8–6,6% во всех опытных группах. По результатам оценки индекса эффективности производства мяса птицы предлагаем при выращивании цыплят-бройлеров в целях повышения уровня рентабельности включать в состав полнорационного комбикорма экстракт крапивы двудомной в дозе 10 мг/кг массы тела

Stimulated emission of surface plasmon polaritons

We have observed laser-like emission of surface plasmon polaritons (SPPs) decoupled to the glass prism in an attenuated total reflection setup. SPPs were excited by optically pumped molecules in a polymeric film deposited on the top of the silver film. Stimulated emission was characterized by a distinct threshold in the input-output dependence and narrowing of the emission spectrum. The observed stimulated emission and corresponding to it compensation of the metallic absorption loss by gain enables many applications of metamaterials and nanoplasmonic devices.Comment: 8 pages; 3 figure

Bimodal Brightness Oscillations in Models of Young Binary Systems

We consider a model for the cyclic activity of young binary stars that accrete matter from the remnants of a protostellar cloud. If the orbit of such a binary system is inclined at a small angle to the line of sight, then the streams of matter and the density waves excited in the circumbinary disk can screen the primary component of the binary from the observer. To study these phenomena by the SPH (smoothed particle hydrodynamics) method, we have computed grids of hydrodynamic models for binary systems based on which we have constructed the light curves as a function of the orbital phase.The main emphasis is on investigating the properties of the brightness oscillations. Therefore, the model parameters were varied within the following ranges: the component mass ratio q = M2 : M1 = 0.2 - 0.5 and the eccentricity e = 0 - 0.7. The parameter that defined the binary viscosity was also varied. We adopted optical grain characteristics typical of circumstellar dust. Our computations have shown that bimodal oscillations are excited in binaries with eccentric orbits, provided that the binary components do not differ too much in mass. In this case, the ratios of the periods and amplitudes of the bimodal oscillations and their shape depend strongly on the inclination of the binary plane and its orientation relative to the observer. Our analysis shows that the computed light curves can be used in interpreting the cyclic activity of UX Ori stars.Comment: 14 pages, 5 figures, 1 tabl

Ultraviolet Spectroscopy of Asteroid (4) Vesta

We report a comprehensive review of the UV-visible spectrum and rotational lightcurve of Vesta combining new observations by Hubble Space Telescope and Swift Gamma-ray Burst Observatory with archival International Ultraviolet Explorer observations. The geometric albedos of Vesta from 220 nm to 953 nm are derived by carefully comparing these observations from various instruments at different times and observing geometries. Vesta has a rotationally averaged geometric albedo of 0.09 at 250 nm, 0.14 at 300 nm, 0.26 at 373 nm, 0.38 at 673 nm, and 0.30 at 950 nm. The linear spectral slope as measured between 240 and 320 nm in the ultraviolet displays a sharp minimum near a sub-Earth longitude of 20^{\circ}, and maximum in the eastern hemisphere. This is consistent with the longitudinal distribution of the spectral slope in the visible wavelength. The photometric uncertainty in the ultraviolet is ~20%, and in the visible wavelengths it is better than 10%. The amplitude of Vesta's rotational lightcurves is ~10% throughout the range of wavelengths we observed, but is smaller at 950 nm (~6%) near the 1-\mum band center. Contrary to earlier reports, we found no evidence for any difference between the phasing of the ultraviolet and visible/near-infrared lightcurves with respect to sub-Earth longitude. Vesta's average spectrum between 220 and 950 nm can well be described by measured reflectance spectra of fine particle howardite-like materials of basaltic achondrite meteorites. Combining this with the in-phase behavior of the ultraviolet, visible, and near-infrared lightcurves, and the spectral slopes with respect to the rotational phase, we conclude that there is no global ultraviolet/visible reversal on Vesta. Consequently, this implies a lack of global space weathering on Vesta, as previously inferred from visible-near-infrared data.Comment: 44 pages, 5 figures, 1 tabl

k-strings and baryon vertices in SU(N) gauge theories

It is pointed out that the sine law for the k-string tension emerges as the critical threshold below which the spatial Z_N symmetry of the static baryon potential is spontaneously broken. This result applies not only to SU(N) gauge theories, but to any gauge system with stable k-strings admitting a baryon vertex made with N sources in the fundamental representation. Some simple examples are worked out.Comment: 4 pages, 4 figures, v2: reference added, v3: comments and references adde

Magnetic fields and accretion flows on the classical T Tauri star V2129 Oph

From observations collected with the ESPaDOnS spectropolarimeter, we report the discovery of magnetic fields at the surface of the mildly accreting classical T Tauri star V2129 Oph. Zeeman signatures are detected, both in photospheric lines and in the emission lines formed at the base of the accretion funnels linking the disc to the protostar, and monitored over the whole rotation cycle of V2129 Oph. We observe that rotational modulation dominates the temporal variations of both unpolarized and circularly polarized line profiles. We reconstruct the large-scale magnetic topology at the surface of V2129 Oph from both sets of Zeeman signatures simultaneously. We find it to be rather complex, with a dominant octupolar component and a weak dipole of strengths 1.2 and 0.35 kG, respectively, both slightly tilted with respect to the rotation axis. The large-scale field is anchored in a pair of 2-kG unipolar radial field spots located at high latitudes and coinciding with cool dark polar spots at photospheric level. This large-scale field geometry is unusually complex compared to those of non-accreting cool active subgiants with moderate rotation rates. As an illustration, we provide a first attempt at modelling the magnetospheric topology and accretion funnels of V2129 Oph using field extrapolation. We find that the magnetosphere of V2129 Oph must extend to about 7R* to ensure that the footpoints of accretion funnels coincide with the high-latitude accretion spots on the stellar surface. It suggests that the stellar magnetic field succeeds in coupling to the accretion disc as far out as the corotation radius, and could possibly explain the slow rotation of V2129 Oph. The magnetospheric geometry we derive produces X-ray coronal fluxes typical of those observed in cTTSs.Comment: MNRAS, in press (18 pages, 17 figures

Gamow-Teller Strength in the A=14 Multiplet: A Challenge to the Shell Model

A new experimental approach to the famous problem of the anomalously slow Gamow-Teller (GT) transitions in the {beta} decay of the A = 14 multiplet is presented. The GT strength distributions to excited states in {sup 14}C and {sup 14}O was studied in high-resolution (d,{sup 2}He) and ({sup 3}He,t) charge-exchange reactions on {sup 14}N. No-core shell-model (NCSM) calculations capable of reproducing the suppression of the {beta} decays predict a selective excitation of J{sup {pi}} = 2{sup +} states. The experimental confirmation represents a validation of the assumptions about the underlying structure of the {sup 14}N ground state wave function. However, the fragmentation of the GT strength over three 2{sup +} final states remains a fundamental issue not explained by the present NCSM using a 6 {h_bar}{omega} model space, suggesting possibly the need to include cluster structure in these light nuclei in a consistent way