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Spin-accumulation and spin-current profiles are calculated for a disordered Pt film subjected to an in-plane electric current within the nonequilibrium Green's function approach. In the bulklike region of the sample, this approach captures the intrinsic spin Hall effect found in other calculations. Near the surfaces, the results reveal qualitative differences with the results of the widely used spin-diffusion model, even when the boundary conditions are modified to try to account for them. One difference is that the effective spin-diffusion length for transverse spin transport is significantly different from its longitudinal counterpart and is instead similar to the mean-free path. This feature may be generic for spin currents generated via the intrinsic spin Hall mechanism because of the differences in transport mechanisms compared to longitudinal spin transport. Orbital accumulation in the Pt film is only significant in the immediate vicinity of the surfaces and has a small component penetrating into the bulk only in the presence of spin-orbit coupling, as a secondary effect induced by the spin accumulation. 

ABSTRACT Natural selection shapes traits during evolution including animal coloration known to be important for concealment and communication and color has been particularly salient in the explosive radiation of cichlid fish species in the rift valley lakes of East Africa. Though selection can produce variation in color via genetic substrates during early development, plasticity in coloration can occur through endocrine, neural and transcriptional cues in response to various environmental stimuli. It is well known that some animals often change color to match their visual ecology. Adult male cichlid fish (Astatotilapia burtoni, Lake Tanganyika) can switch between blue and yellow body colors. Different colors result from the expression of pigment-bearing cells, which differ in density and function between these two color morphs. We show thatA. burtoniswitches from yellow to blue depending on their visual environment by downregulating endothelin receptor B (EdnRB) mRNA via DNA hypermethylation at a single cytosine residue within its promoter. EdnRB functions in yellow chromatophores to signal the aggregation of yellow pigments, making yellow less visible. Taken together, the regulation ofEdnRBthrough DNA methylation in yellow chromatophores, in part, contributes to pigmentation changes from blue to yellow, depending on visual environment. 

Abstract We present cosmological constraints on deviations from general relativity (GR) from the first-year of clustering observations from the Dark Energy Spectroscopic Instrument (DESI) in combination with other available datasets including the CMB data from Planck with CMB-lensing from Planck and ACT, BBN constraints on the physical baryon density, the galaxy weak lensing and clustering from DESY3 and supernova data from DESY5. We first consider the  μ(a,k)–Σ(a,k) modified gravity (MG) parameterization (as well asη(a,k)) in a ΛCDM and aw₀w_aCDM cosmological backgrounds. Using a functional form for time-only evolution givesμ₀= 0.11^+0.44_-0.54from DESI(FS+BAO)+BBN and a wide prior onn_s. Using DESI(FS+BAO)+CMB+DESY3+DESY5-SN, we obtainμ₀= 0.05 ± 0.22 and Σ₀= 0.008 ± 0.045 and similarlyμ₀= 0.02^+0.19_-0.24andη₀= 0.09^+0.36_-0.60, in an ΛCDM background. Inw₀w_aCDM we obtainμ₀= -0.24^+0.32_-0.28and Σ₀= 0.006 ± 0.043, consistent with GR, and we still find a preference of the data for a dynamical dark energy withw₀> -1 andw_a< 0. Using functional dependencies in both time and scale givesμ₀and Σ₀with a same level of precision as above but other scale MG parameters remain hard to constrain. We then move to binned parameterizations in a ΛCDM background starting with two bins in redshift and obtain,μ₁= 1.02 ± 0.13,μ₂= 1.04 ± 0.11, Σ₁= 1.021 ± 0.029 and Σ₂= 1.022^+0.027_-0.023, all consistent with the unity value of GR in the binning formalism. We then extend the analysis to combine two bins in redshift and two in scale giving 8 MG parameters that we find all consistent with GR. We note that we find here that the tension reported in previous studies about Σ₀being inconsistent with GR when using Planck PR3 data goes away when we use the recentLoLLiPoP+HiLLiPoPlikelihoods. As noted in previous studies, this seems to indicate that the tension is indeed related to the CMB lensing anomaly in PR3 which is also resolved when using the recent likelihoods. We then constrain the class of Horndeski theory in the effective field theory of dark energy approach. We consider both EFT-basis andα-basis in the analysis. Assuming a power law parameterization for the EFT function Ω, which controls non-minimal coupling, we obtain Ω₀= 0.012^+0.001_-0.012ands₀= 0.996^+0.54_-0.20from the combination of DESI(FS+BAO)+DESY5SN+CMB in a ΛCDM background, which are consistent with GR. Similar results are obtained when using theα-basis and assuming no-braiding (α_B= 0) giving  c_M< 1.14 at 95% CL in a ΛCDM background, also in agreement with GR. However, we see a mild yet consistent indication forc_B> 0 whenα_Bis allowed to vary which will require further study to determine whether this is due to systematics or new physics.