2,010 research outputs found

    Morphological characterization of Achai cattle in sedentary and transhumant systems in Pakistan

    Get PDF
    Achai is an as yet undocumented but well-adapted cattle breed of the Hindu Kush Mountains of northern Pakistan, which is reared under sedentary farming system (SFS) and transhumant farming system (TFS). This paper compares the morphological (physical and morphometric) characteristics of this cattle breed under both farming systems to know the effect of these styles of management. Data were collected from 108 adult females and 108 males in SFS and 108 females and 36 males in TFS on physical characteristics (colour of the coat, horns, eyelashes, muzzle, hoof, switch) and morphometric measurements - i.e. heart girth, body length, height at withers, height at hipbone, face length, horn length, horn circumference, ear (length and width), neck length, dewlap length, chine length, loin length, rump (length and width), length below knee, hoof circumference, tail and switch length. Results showed that farming systems significantly affect most of the morphological characteristics of both sexes, particularly the morphometric measurements with tall and leggy conformation for TFS cows and bulls. This indicates an adaptation to long distance transhumance and mountain terrain grazing. It can be concluded that the Achai has the potential to adapt to the requirements of specific farming systems. There is hence a need for the conservation of its adaptive traits in both farming system

    Rb-Sr, Sm-Nd and Ar-Ar isotopic systematics of Antarctic nakhlite Yamato 000593

    Get PDF
    sotopic analysis of the newly found Antarctic nakhlite Yamato (Y) 000593 yields a Rb-Sr age of 1.30±0.02Ga with an initial ^(87)Sr/^(86)Sr of 0.702525±0.000027, a Sm-Nd age of 1.31±0.03Ga with an initial ε_(Nd) of + 16.0±0.2 and an Ar-Ar isochron age of <=1.36Ga. The concordancy of these three ages and Rb-Sr and Sm-Nd initial isotopic signatures strongly suggest that Y000593 crystallized from low Rb/Sr, light REE-depleted source materials ~1.31Ga ago. The crystallization age of Y000593 is compared with the age data of non-Antarctic nakhlites (Nakhla, Governador Valadares, Lafayette and Northwest Africa 998) and Chassigny. The initial Sr and Nd isotopic signatures suggest that Lafayette and Y000593 were co-magmatic or at least came from very similar magmas. Cosmogenic ^(36)Ar concentrations in Y000593 resemble those in other nakhlites. The similarities in crystallization and ejection ages and in petrologic features suggest the nakhlites were derived from similar source regions, and launch pairing of nakhlites and Chassigny. The Rb-Sr data for Y000593 show that the isotopic system is disturbed by pre-terrestrial alteration of olivine. Although many of the acid-leached residues of mineral fractions fall along the 1.30Ga Rb-Sr isochron, leached olivine does not. This indicates the lack of isotopic equilibrium between the olivine fractions and the secondary alteration phases. A tie-line between two olivine leachates provides a calculated "age" of 650±80Ma with an initial ^(87)Sr/^(86)Sr of ~0.70465, which gives a hint for the isotopic signatures of local brine as well as the timing of an aqueous alteration event on the Martian surface

    Morphological characterization of the Azikheli buffalo in Pakistan

    Get PDF
    This study aims to characterize Azikheli, an undocumented buffalo breed, in its home tract (Khwazakhela, Swat, Pakistan) under traditional farming conditions. For this purpose, 108 buffalo cows and 27 bulls were randomly selected. Mean, standard error, Student's t test and Chi-square test were used for various comparisons. The results show that the majority of animals have a brown coat colour. Cows have significantly higher heart girths, longer horns, longer necks and wider faces at the level of the eyes than bulls, whereas bulls have significantly longer bodies, longer ears, thicker horns, thicker necks and larger hooves than cows. Horns are flat laterally, directed backwards and then slightly upwards without twisting, leading to a sickle to semi-sickle appearance. Owing to its small body size and brown coat colour, the breed is well adapted to mountain slope grazing and thrives well away from swamps. Its adaptation to mountainous ecosystems warrants its in situ conservatio

    Longitudinal evidence for 4-year-olds’ but not 2- and 3-year-olds’ false belief-related action anticipation

    Get PDF
    Recently, infants younger than 2 years have been shown to display correct expectations of the actions of an agent with a false belief. The developmental trajectory of these early-developing abilities and their robustness, however, remain a matter of debate. Here, we tested children longitudinally from 2 to 4 years of age with an established anticipatory looking false belief task, and found a significant developmental change between the ages of 3 and 4 years. Children anticipated correctly only by the age of 4 years, and performed at chance at the ages of 2 and 3 years. Moreover, we found correct anticipation only when the agent falsely believed an object to be in its last rather than a previous location. These findings point towards the fragility of early belief-related action anticipation before the age of 4 years, when children start passing traditional false belief tasks

    Heavy Carriers and Non-Drude Optical Conductivity in MnSi

    Full text link
    Optical properties of the weakly helimagnetic metal MnSi have been determined in the photon energy range from 2 meV to 4.5 eV using the combination of grazing incidence reflectance at 80 degrees (2 meV to 0.8 eV) and ellipsometry (0.8 to 4.5 eV). As the sample is cooled below 100 K the effective mass becomes strongly frequency dependent at low frequencies, while the scattering rate developes a linear frequency dependence. The complex optical conductivity can be described by the phenomenological relation \sigma(\omega,T) \propto (\Gamma(T)+i\omega)^{-1/2} used for cuprates and ruthenates.Comment: 5 pages, ReVTeX 4, 5 figures in eps forma

    The Interface Region Imaging Spectrograph (IRIS)

    Get PDF
    The Interface Region Imaging Spectrograph (IRIS) small explorer spacecraft provides simultaneous spectra and images of the photosphere, chromosphere, transition region, and corona with 0.33-0.4 arcsec spatial resolution, 2 s temporal resolution and 1 km/s velocity resolution over a field-of-view of up to 175 arcsec x 175 arcsec. IRIS was launched into a Sun-synchronous orbit on 27 June 2013 using a Pegasus-XL rocket and consists of a 19-cm UV telescope that feeds a slit-based dual-bandpass imaging spectrograph. IRIS obtains spectra in passbands from 1332-1358, 1389-1407 and 2783-2834 Angstrom including bright spectral lines formed in the chromosphere (Mg II h 2803 Angstrom and Mg II k 2796 Angstrom) and transition region (C II 1334/1335 Angstrom and Si IV 1394/1403 Angstrom). Slit-jaw images in four different passbands (C II 1330, Si IV 1400, Mg II k 2796 and Mg II wing 2830 Angstrom) can be taken simultaneously with spectral rasters that sample regions up to 130 arcsec x 175 arcsec at a variety of spatial samplings (from 0.33 arcsec and up). IRIS is sensitive to emission from plasma at temperatures between 5000 K and 10 MK and will advance our understanding of the flow of mass and energy through an interface region, formed by the chromosphere and transition region, between the photosphere and corona. This highly structured and dynamic region not only acts as the conduit of all mass and energy feeding into the corona and solar wind, it also requires an order of magnitude more energy to heat than the corona and solar wind combined. The IRIS investigation includes a strong numerical modeling component based on advanced radiative-MHD codes to facilitate interpretation of observations of this complex region. Approximately eight Gbytes of data (after compression) are acquired by IRIS each day and made available for unrestricted use within a few days of the observation.Comment: 53 pages, 15 figure

    Saturation of electrical resistivity

    Full text link
    Resistivity saturation is observed in many metallic systems with a large resistivity, i.e., when the resistivity has reached a critical value, its further increase with temperature is substantially reduced. This typically happens when the apparent mean free path is comparable to the interatomic separations - the Ioffe-Regel condition. Recently, several exceptions to this rule have been found. Here, we review experimental results and early theories of resistivity saturation. We then describe more recent theoretical work, addressing cases both where the Ioffe-Regel condition is satisfied and where it is violated. In particular we show how the (semiclassical) Ioffe-Regel condition can be derived quantum-mechanically under certain assumptions about the system and why these assumptions are violated for high-Tc cuprates and alkali-doped fullerides.Comment: 16 pages, RevTeX, 15 eps figures, additional material available at http://www.mpi-stuttgart.mpg.de/andersen/saturation

    Weak Localization Effect in Superconductors by Radiation Damage

    Get PDF
    Large reductions of the superconducting transition temperature TcT_{c} and the accompanying loss of the thermal electrical resistivity (electron-phonon interaction) due to radiation damage have been observed for several A15 compounds, Chevrel phase and Ternary superconductors, and NbSe2\rm{NbSe_{2}} in the high fluence regime. We examine these behaviors based on the recent theory of weak localization effect in superconductors. We find a good fitting to the experimental data. In particular, weak localization correction to the phonon-mediated interaction is derived from the density correlation function. It is shown that weak localization has a strong influence on both the phonon-mediated interaction and the electron-phonon interaction, which leads to the universal correlation of TcT_{c} and resistance ratio.Comment: 16 pages plus 3 figures, revtex, 76 references, For more information, Plesse see http://www.fen.bilkent.edu.tr/~yjki
    corecore