1,390 research outputs found

    Shift in Management Strategy of Yak Herding in the South of Mustang District, Nepal, Himalaya

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    In the Himalayan regions of Nepal, people herd yaks (Bos grunniens) under transhumant pastoralism, seasonal migrations of herds between summer highlands and winter lowlands. For several decades, the number of yaks has decreased, and the management strategy of yak herding has been altered due to the influence of substantial changes in both the social environment and their livelihoods. We conducted field surveys on yak herding in the south of Mustang District from 2012 to 2016 to examine the recent shift in management strategy and practice. The surveys were focused on fifteen yak owners and their herdsmen who lived in southernmost three villages in the district and organized a yak owners’ cooperative group. The herd scale has been constant in recent years, although the owners had a willingness to increase the scale. The herding practices were traditional and extensive, which might not have led to an increase in herd size or productivity. Dairy production has shown an obvious declining trend, whereas sales of meat and the revenue from the yak blood drinking festival hosted by the cooperative group have become more important income sources for local yak herding in association with the development of local infrastructures and livelihoods. Because the economic incentives for yak herding remained strong in the study area, the herding scale will be maintained, or expanded if the management practices are improved in the future

    Orbital Degeneracy and Peierls Instability in Triangular Lattice Superconductor Ir1−x_{1-x}Ptx_xTe2_2

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    We have studied electronic structure of triangular lattice Ir1−x_{1-x}Ptx_xTe2_2 superconductor using photoemission spectroscopy and model calculations. Ir 4f4f core-level photoemission spectra show that Ir 5d5d t2gt_{2g} charge modulation established in the low temperature phase of IrTe2_2 is suppressed by Pt doping. This observation indicates that the suppression of charge modulation is related to the emergence of superconductivity. Valence-band photoemission spectra of IrTe2_2 suggest that the Ir 5d5d charge modulation is accompanied by Ir 5d5d orbital reconstruction. Based on the photoemission results and model calculations, we argue that the orbitally-induced Peierls effect governs the charge and orbital instability in the Ir1−x_{1-x}Ptx_xTe2_2.Comment: 5 pages,4 figure

    A clinical evaluation of the Dow Corning silcon contact lens

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    A clinical evaluation was made of the Dow Corning SILCON lens. Designed to be optically clear and stable, it also has the highest 0xygen permeability of all other rigid lenses presently available. Physiological difficulties with the lens such as its non-wetting surface accounted for most of the initial fitting failures. The first fit success of fourteen eyes was twenty-nine percent. This increased to seventy percent after one lens reorder and after a second reorder success was achieved for all patients. The base curves of all the lenses were verified before dispensing and at the last progress exam. Some changes were found, but they were statistically insignificant at the .01 level. The findings also showed changes that suggested increased corneal thickness with initial wear and a subsequent decrease in thickness as wearing time increased

    Electronic structure reconstruction by orbital symmetry breaking in IrTe2

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    We report an angle-resolved photoemission spectroscopy (ARPES) study on IrTe2 which exhibits an interesting lattice distortion below 270 K and becomes triangular lattice superconductors by suppressing the distortion via chemical substitution or intercalation. ARPES results at 300 K show multi-band Fermi surfaces with six-fold symmetry which are basically consistent with band structure calculations. At 20 K in the distorted phase, whereas the flower shape of the outermost Fermi surface does not change from that at 300 K, topology of the inner Fermi surfaces is strongly modified by the lattice distortion. The Fermi surface reconstruction by the distortion depends on the orbital character of the Fermi surfaces, suggesting importance of Ir 5d and/or Te 5p orbital symmetry breaking.Comment: 4pages, 4figure

    Interindividual Differences and Their Consistency in Grazing Cattle Behavior across Seasons

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    Interindividual differences and their consistency in behavior were investigated for cattle (Bos taurus) grazing a bahiagrass (Paspalum notatum) and centipedegrass (Eremochloa ophiuroides) dominated pasture as a herd of about 30 breeding cows with their calves. Behavior of the cows was monitored directly by observers and also using GPS and accelerometer data loggers attached to focal cows for a period of 1–5 days every month during the grazing seasons (from May to October) in 2018 and 2019. The data were converted into behavioral variables (e.g. time spent grazing, ruminating and resting, time spent in particular areas, and selectivity for grass species). Time budget of the maintenance behavior, spatial use pattern, preference for grass species on a daily basis were different among cows consistently across the seasons although the behavior varied daily and seasonally in accordance with sward and weather conditions, i.e. some individuals showed a particular tendency in some behavioral traits compared with others across various environmental situations. The consistent individual behavioral characteristics found in this study can be partly explained by age, body size and nutritional and physiological states; otherwise considered as personal traits of animals, which may affect their ecological fitness to the environment and production performances as livestock and be transmitted to their offspring. Further studies are warranted to reveal associations of behavioral traits with fitness or productivity and their transmissibility

    Effect of electron-phonon coupling in the ARPES spectra of the tri-layer cuprate Bi2_2Sr2_2Ca2_2Cu3_3O10+δ_{10+\delta}

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    Angle-resolved photoemission spectroscopy using tunable low energy photons allows us to study the quasi-particle (QP) dispersions of the inner and outer CuO2 planes (IP and OP) separately in the tri-layer cuprate Bi2_2Sr2_2Ca2_2Cu3_3O10+δ_{10+\delta} (Bi2223). The kink energy of the OP band is ∼\sim 70 meV, as observed in various high-TcT_c cuprates, while that of the IP band is as large as 100 meV in the superconducting (SC) state. This large kink energy is attributed to the ∼\sim 35 meV buckling mode plus the large (∼\sim 60 meV) SC gap of IP. The IP band also shows a weak kink feature at 70 meV in the SC state. The latter feature can be explained either by the 70 meV half-breathing mode or by the ∼\sim 35 meV buckling-phonon mode plus the ∼\sim 40 meV SC gap of OP if interlayer scattering of QP is involved.Comment: 5 pages, 2 figure

    An energy scale directly related to superconductivity in the high-TcT_c cuprate superconductors: Universality from the Fermi arc picture

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    We have performed a temperature dependent angle-resolved photoemission spectroscopy (ARPES) study of the tri-layer high-TcT_c cuprate superconductor (HTSC) Bi2_2Sr2_2Ca2_2Cu3_3O10+δ_{10+\delta} (Bi2223), and have shown that the \textquotedblleft effective\textquotedblright superconducting (SC) gap Δsc\Delta_{\rm{sc}} defined at the end point of the Fermi arc and the TcT_c (= 110 K) approximately satisfies the weak-coupling BCS-relationship 2Δsc\Delta_{\rm{sc}} = 4.3kBTck_{\rm{B}}T_c. Combining this result with previous ARPES results on single- and double-layer cuprates, we show that the relationship between 2Δsc\Delta_{\rm{sc}} = 4.3kBTck_{\rm{B}}T_c holds for various HTSCs. Furthermore, at TT ∼\sim TcT_c, the quasi-patricle width at the end point of the Fermi arc is found to coincide with Δsc\Delta_{\rm{sc}}, consistent with the context of Planckian dissipation.Comment: 5 pages, 4 figure
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