1,395 research outputs found
Shift in Management Strategy of Yak Herding in the South of Mustang District, Nepal, Himalaya
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 IrPtTe
We have studied electronic structure of triangular lattice
IrPtTe superconductor using photoemission spectroscopy and
model calculations. Ir core-level photoemission spectra show that Ir
charge modulation established in the low temperature phase of IrTe
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 IrTe suggest that the Ir charge
modulation is accompanied by Ir 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 IrPtTe.Comment: 5 pages,4 figure
A clinical evaluation of the Dow Corning silcon contact lens
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
Interindividual Differences and Their Consistency in Grazing Cattle Behavior across Seasons
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
Electronic structure reconstruction by orbital symmetry breaking in IrTe2
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
Effect of electron-phonon coupling in the ARPES spectra of the tri-layer cuprate BiSrCaCuO
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
BiSrCaCuO (Bi2223). The kink energy of the OP
band is 70 meV, as observed in various high- 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 35 meV buckling mode plus the
large ( 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 35 meV buckling-phonon mode plus the
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- cuprate superconductors: Universality from the Fermi arc picture
We have performed a temperature dependent angle-resolved photoemission
spectroscopy (ARPES) study of the tri-layer high- cuprate superconductor
(HTSC) BiSrCaCuO (Bi2223), and have shown that
the \textquotedblleft effective\textquotedblright superconducting (SC) gap
defined at the end point of the Fermi arc and the (=
110 K) approximately satisfies the weak-coupling BCS-relationship
2 = 4.3. Combining this result with previous
ARPES results on single- and double-layer cuprates, we show that the
relationship between 2 = 4.3 holds for various
HTSCs. Furthermore, at , the quasi-patricle width at the end
point of the Fermi arc is found to coincide with , consistent
with the context of Planckian dissipation.Comment: 5 pages, 4 figure
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