348 research outputs found
Standard metabolic rate predicts growth trajectory of juvenile Chinese crucian carp (Carassius auratus) under changing food availability
Phenotypic traits vary greatly within populations and can have a significant influence on aspects of performance. The present study aimed to investigate the effects of individual variation in standard metabolic rate (SMR) on growth rate and tolerance to food-deprivation in juvenile crucian carp (Carassius auratus) under varying levels of food availability. To address this issue, 19 high and 16 low SMR (individuals were randomly assigned to a satiation diet for 3 weeks, whereas another 20 high and 16 low SMR individuals were assigned to a restricted diet (approximately 50% of satiation) for the same period. Then, all fish were completely food-deprived for another 3 weeks. High SMR individuals showed a higher growth rate when fed to satiation, but this advantage of SMR did not exist in food-restricted fish. This result was related to improved feeding efficiency with decreased food intake in low SMR individuals, due to their low food processing capacity and maintenance costs. High SMR individuals experienced more mass loss during food-deprivation as compared to low SMR individuals. Our results here illustrate context-dependent costs and benefits of intraspecific variation in SMR whereby high SMR individuals show increased growth performance under high food availability but had a cost under stressful environments (i.e., food shortage)
Emergence of flat bands and their impact on superconductivity of MoSiP
The first-principles calculations and measurements of the magnetic
penetration depths, the upper critical field, and the specific heat were
performed for a family of MoSiP superconducotrs.
First-principles calculations suggest the presence of a flat band dispersion,
which gradually shifts to the Fermi level as a function of phosphorus doping
. The flat band approaches the Fermi level at , thus separating
MoSiP between the purely steep band and the steep band/flat
band superconducting regimes. The emergence of flat bands lead to an abrupt
change of nearly all the superconducting quantities. In particular, a strong
reduction of the coherence length and enhancement of the penetration
depth result in nearly factor of three increase of the
Ginzburg-Landau parameter (from for
to for ) thus initiating the
transition of MoSiP from a moderate to an extreme type-II
superconductivity.Comment: 6 pages, 4 figure
Photochemical reaction enabling the engineering of photonic spin-orbit coupling in organic-crystal optical microcavities
The control and active manipulation of spin-orbit coupling (SOC) in photonic
systems is fundamental in the development of modern spin optics and topological
photonic devices. Here, we demonstrate the control of an artificial
Rashba-Dresselhaus (RD) SOC mediated by photochemical reactions in a
microcavity filled with an organic single-crystal of photochromic phase-change
character. Splitting of the circular polarization components of the optical
modes induced by photonic RD SOC is observed experimentally in momentum space.
By applying an ultraviolet light beam, we control the spatial molecular
orientation through a photochemical reaction and with that we control the
energies of the photonic modes. This way we realize a reversible conversion of
spin-splitting of the optical modes with different energies, leading to an
optically controlled switching between circularly and linearly polarized
emission from our device. Our strategy of in situ and reversible engineering of
SOC induced by a light field provides a promising approach to actively design
and manipulate synthetic gauge fields towards future on-chip integration in
photonics and topological photonic devices
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