TY - JOUR AB - We study how a block of genome with a large number of weakly selected loci introgresses under directional selection into a genetically homogeneous population. We derive exact expressions for the expected rate of growth of any fragment of the introduced block during the initial phase of introgression, and show that the growth rate of a single-locus variant is largely insensitive to its own additive effect, but depends instead on the combined effect of all loci within a characteristic linkage scale. The expected growth rate of a fragment is highly correlated with its long-term introgression probability in populations of moderate size, and can hence identify variants that are likely to introgress across replicate populations. We clarify how the introgression probability of an individual variant is determined by the interplay between hitchhiking with relatively large fragments during the early phase of introgression and selection on fine-scale variation within these, which at longer times results in differential introgression probabilities for beneficial and deleterious loci within successful fragments. By simulating individuals, we also investigate how introgression probabilities at individual loci depend on the variance of fitness effects, the net fitness of the introduced block, and the size of the recipient population, and how this shapes the net advance under selection. Our work suggests that even highly replicable substitutions may be associated with a range of selective effects, which makes it challenging to fine map the causal loci that underlie polygenic adaptation. AU - Sachdeva, Himani AU - Barton, Nicholas H ID - 39 IS - 4 JF - Genetics SN - 00166731 TI - Replicability of introgression under linked, polygenic selection VL - 210 ER - TY - JOUR AB - We analyze the theoretical derivation of the beyond-mean-field equation of state for two-dimensional gas of dilute, ultracold alkali-metal atoms in the Bardeen–Cooper–Schrieffer (BCS) to Bose–Einstein condensate (BEC) crossover. We show that at zero temperature our theory — considering Gaussian fluctuations on top of the mean-field equation of state — is in very good agreement with experimental data. Subsequently, we investigate the superfluid density at finite temperature and its renormalization due to the proliferation of vortex–antivortex pairs. By doing so, we determine the Berezinskii–Kosterlitz–Thouless (BKT) critical temperature — at which the renormalized superfluid density jumps to zero — as a function of the inter-atomic potential strength. We find that the Nelson–Kosterlitz criterion overestimates the BKT temperature with respect to the renormalization group equations, this effect being particularly relevant in the intermediate regime of the crossover. AU - Bighin, Giacomo AU - Salasnich, Luca ID - 420 IS - 17 JF - International Journal of Modern Physics B TI - Renormalization of the superfluid density in the two-dimensional BCS-BEC crossover VL - 32 ER - TY - JOUR AB - Genomes of closely-related species or populations often display localized regions of enhanced relative sequence divergence, termed genomic islands. It has been proposed that these islands arise through selective sweeps and/or barriers to gene flow. Here, we genetically dissect a genomic island that controls flower color pattern differences between two subspecies of Antirrhinum majus, A.m.striatum and A.m.pseudomajus, and relate it to clinal variation across a natural hybrid zone. We show that selective sweeps likely raised relative divergence at two tightly-linked MYB-like transcription factors, leading to distinct flower patterns in the two subspecies. The two patterns provide alternate floral guides and create a strong barrier to gene flow where populations come into contact. This barrier affects the selected flower color genes and tightlylinked loci, but does not extend outside of this domain, allowing gene flow to lower relative divergence for the rest of the chromosome. Thus, both selective sweeps and barriers to gene flow play a role in shaping genomic islands: sweeps cause elevation in relative divergence, while heterogeneous gene flow flattens the surrounding "sea," making the island of divergence stand out. By showing how selective sweeps establish alternative adaptive phenotypes that lead to barriers to gene flow, our study sheds light on possible mechanisms leading to reproductive isolation and speciation. AU - Tavares, Hugo AU - Whitley, Annabel AU - Field, David AU - Bradley, Desmond AU - Couchman, Matthew AU - Copsey, Lucy AU - Elleouet, Joane AU - Burrus, Monique AU - Andalo, Christophe AU - Li, Miaomiao AU - Li, Qun AU - Xue, Yongbiao AU - Rebocho, Alexandra B AU - Barton, Nicholas H AU - Coen, Enrico ID - 38 IS - 43 JF - PNAS SN - 00278424 TI - Selection and gene flow shape genomic islands that control floral guides VL - 115 ER - TY - CONF AB - There is currently significant interest in operating devices in the quantum regime, where their behaviour cannot be explained through classical mechanics. Quantum states, including entangled states, are fragile and easily disturbed by excessive thermal noise. Here we address the question of whether it is possible to create non-reciprocal devices that encourage the flow of thermal noise towards or away from a particular quantum device in a network. Our work makes use of the cascaded systems formalism to answer this question in the affirmative, showing how a three-port device can be used as an effective thermal transistor, and illustrates how this formalism maps onto an experimentally-realisable optomechanical system. Our results pave the way to more resilient quantum devices and to the use of thermal noise as a resource. AU - Xuereb, André AU - Aquilina, Matteo AU - Barzanjeh, Shabir ED - Andrews, D L ED - Ostendorf, A ED - Bain, A J ED - Nunzi, J M ID - 155 TI - Routing thermal noise through quantum networks VL - 10672 ER - TY - JOUR AB - Cuprate superconductors have long been thought of as having strong electronic correlations but negligible spin-orbit coupling. Using spin- and angle-resolved photoemission spectroscopy, we discovered that one of the most studied cuprate superconductors, Bi2212, has a nontrivial spin texture with a spin-momentum locking that circles the Brillouin zone center and a spin-layer locking that allows states of opposite spin to be localized in different parts of the unit cell. Our findings pose challenges for the vast majority of models of cuprates, such as the Hubbard model and its variants, where spin-orbit interaction has been mostly neglected, and open the intriguing question of how the high-temperature superconducting state emerges in the presence of this nontrivial spin texture. AU - Gotlieb, Kenneth AU - Lin, Chiu-Yun AU - Serbyn, Maksym AU - Zhang, Wentao AU - Smallwood, Christopher L. AU - Jozwiak, Christopher AU - Eisaki, Hiroshi AU - Hussain, Zahid AU - Vishwanath, Ashvin AU - Lanzara, Alessandra ID - 5767 IS - 6420 JF - Science SN - 0036-8075 TI - Revealing hidden spin-momentum locking in a high-temperature cuprate superconductor VL - 362 ER -