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Journey to the West: Trans-Pacific Historical Biogeography of Fringehead Blennies in the Genus Neoclinus (Teleostei: Blenniiformes).
Several temperate marine taxa of the northern hemisphere follow a trans-Pacific biogeographic track with representatives on either side of the intervening boreal waters. Shelter-dwelling blenniiform fishes of the genus Neoclinus exhibit this trans-Pacific distribution pattern with three species in the eastern North Pacific and eight species in the western North Pacific. We reconstructed the phylogeny of the Neocliniini (Neoclinus and the monotypic Mccoskerichthys) using six genetic markers: four mitochondrial genes (COI, cytochrome b, 12S and 16S), and two nuclear genes (RAG-1, TMO-4C4). Ancestral state reconstruction and molecular clock dating were used to explore hypothetical ancestral distributions and area relationships, and to estimate divergent times within this group. The monophyly of the genus Neoclinus, and the reciprocal monophyly of the eastern Pacific and western Pacific lineages were supported. Available evidence, including the eastern Pacific and western Atlantic occurrence of a New World clade of blennioid fishes that includes this lineage, supports the origin of the Neocliniini in the eastern Pacific with a single divergence event to the west across the North Pacific by the ancestor of the western Pacific clade. Estimated divergence time of the eastern and western Pacific clades of Neoclinus was 24.14 million year ago, which falls during the Oligocene epoch. Estimated times of divergence in other trans-Pacific lineages of marine fishes vary widely, from recent Pleistocene events to as early as 34 mya
Tau longitudinal polarization in B -> D tau nu and its role in the search for charged Higgs boson
We study the longitudinal polarization of the tau lepton in B -> D tau nu
decay. After discussing possible sensitivities of tau decay modes to the tau
polarization, we examine the effect of charged Higgs boson on the tau
polarization in B -> D tau nu. We find a relation between the decay rate and
the tau polarization, and clarify the role of the tau polarization measurement
in the search for the charged Higgs boson.Comment: 17 pages, 3 figures. Tau -> l nu nu is included in Sec. II.
Accordingly the title is changed. References are adde
Magnetic quantum tunnelling in Fe8 with excited nuclei
We investigate the effect of dynamic nuclear spin fluctuation on quantum
tunneling of the magnetization (QTM) in the molecular magnet Fe8 by increasing
the nuclei temperature using radio frequency (RF) pulses before the hysteresis
loop measurements. The RF pulses do not change the electrons spin temperature.
Independently we show that the nuclear spin-spin relaxation time T2 has strong
temperature dependence. Nevertheless, we found no effect of the nuclear spin
temperature on the tunneling probability. This suggests that in our
experimental conditions only the hyperfine field strength is relevant for QTM.
We demonstrate theoretically how this can occur.Comment: 4 pages, 4 figure
Superconducting nanowire single-photon detectors with non-periodic dielectric multilayers
We present superconducting nanowire single-photon detectors (SSPDs) on non-periodic dielectric multilayers, which enable us to design a variety of wavelength dependences of optical absorptance by optimizing the dielectric multilayer. By adopting a robust simulation to optimize the dielectric multilayer, we designed three types of SSPDs with target wavelengths of 500 nm, 800 nm, and telecom range respectively. We fabricated SSPDs based on the optimized designs for 500 and 800 nm, and evaluated the system detection efficiency at various wavelengths. The results obtained confirm that the designed SSPDs with non-periodic dielectric multilayers worked well. This versatile device structure can be effective for multidisciplinary applications in fields such as the life sciences and remote sensing that require high efficiency over a precise spectral range and strong signal rejection at other wavelengths
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