1,736 research outputs found

    Editorial: Rising stars in aquatic physiology: 2022

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    Promoting and visualizing cutting-edge research from young generations is the cornerstone of our academic environment. Under this scenario, this Research Topic aims gathering innovative research studies on aquatic physiology, studies that range from ecological field studies focused on how ocean acidification might affect cleaning fish services in reefs (Paula et al.) to molecular biology studies dedicated to the characterization of genes involved in longevity in two molluscan species (Xu et al.) and cortisol receptors expression in a teleostean fish (Vallejos-Vidal et al.). Additionally, a fourth manuscript has been published in this Research Topic, a very interesting study describing how parental metabolite provisioning is directed to offspring (both spermatozoa and developing embryos) in an elasmobranch lecithotrophic viviparous species (Wosnick et al.).info:eu-repo/semantics/publishedVersio

    Comparison of genetic diversity and growth traits among Fangzheng silver crucian carp (Carassius auratus gibelio) gynogenetic clones

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    The silver crucian carp (Carassius auratus gibelio), a gynogenetic teleost, is a promising model for the study of evolutionary genetics in vertebrates. We identified ten gynogenetic clones (FZ-I~FZ-X) from triploid silver crucian carp, collected from Fangzheng County in Heilongjiang Province, China, using microsatellite markers. The genetic diversity of these gynogenetic clones was analyzed using 52 microsatellite markers. A total of 413 alleles were detected and the length of fragments ranged from 96 to 340 bp. The number of alleles per locus varied from 2~19 (mean=7.9423). The observed heterozygosity at polymorphic loci ranged from 0.10~1.00 (mean=0.80). The average allele count per gynogenetic clone ranged from 1.9423~2.1923. The ratio of the polymorphic locus was from 71.15% (VII) to 84.61% (IX) per clone. The number of genotypes ranged from 2~10 per locus. Ten genotypes were observed by analyzing each of 14 microsatellites. As a result, each gynogenetic clone could be accurately identified. In addition, the growth traits, including body weight, length, and height, among five gynogenetic clones were compared. There was a significant difference among gynogenetic clones. Clone FZ-V exhibited the best growth traits, with the largest body weight (53.17±5.24 g), length (11.38±0.37 cm) and height (4.69±0.18 cm). Our results provide basic data for the identification of silver crucian carp gynogenetic clones and can be used as a guide genetic breeding programs

    The No-Triangle Hypothesis for N=8 Supergravity

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    We study the perturbative expansion of N=8 supergravity in four dimensions from the viewpoint of the ``no-triangle'' hypothesis, which states that one-loop graviton amplitudes in N=8 supergravity only contain scalar box integral functions. Our computations constitute a direct proof at six-points and support the no-triangle conjecture for seven-point amplitudes and beyond.Comment: 43page

    Field-induced gap in the spin-1/2 antiferromagnetic Heisenberg chain: A density matrix renormalization group study

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    We study the spin-1/2 antiferromagnetic Heisenberg chain in both uniform and (perpendicular) staggered magnetic fields using the density-matrix renormalization-group method. This model has been shown earlier to describe the physics of the copper benzoate materials in magnetic field. In the present work, we extend the study to more general case for a systematic investigation of the field-induced gap and related properties of the spin-1/2 antiferromagnetic Heisenberg chain. In particular, we explore the high magnetic field regime where interesting behaviors in the field-induced gap, magnetization, and spin correlation functions are found. Careful examination of the low energy properties and magnetization reveals interesting competing effects of the staggered and uniform fields. The incommensurate behavior in the spin correlation functions is demonstrated and discussed in detail. The present work reproduces earlier results in good agreement with experimental data on copper benzoate and predicts new interesting field-induced features at very high magnetic field.Comment: 8 pages, 6 figure

    Weak localization and conductance fluctuations of a chaotic quantum dot with tunable spin-orbit coupling

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    In a two-dimensional quantum dot in a GaAs heterostructure, the spin-orbit scattering rate is substantially reduced below the rate in a bulk two-dimensional electron gas [B.I. Halperin et al, Phys. Rev. Lett. 86, 2106 (2001)]. Such a reduction can be undone if the spin-orbit coupling parameters acquire a spatial dependence, which can be achieved, e.g., by a metal gate covering only a part of the quantum dot. We calculate the effect of such spatially non-uniform spin-orbit scattering on the weak localization correction and the universal conductance fluctuations of a chaotic quantum dot coupled to electron reservoirs by ballistic point contacts, in the presence of a magnetic field parallel to the plane of the quantum dot.Comment: 4 pages, RevTeX; 2 figures. Substantial revision

    Path integral solution for an angle-dependent anharmonic oscillator

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    We have given a straightforward method to solve the problem of noncentral anharmonic oscillator in three dimensions. The relative propagator is presented by means of path integrals in spherical coordinates. By making an adequate change of time we were able to separate the angular motion from the radial one. The relative propagator is then exactly calculated. The energy spectrum and the corresponding wave functions are obtained.Comment: Corrected typos and mistakes, To appear in Communications in Theoretical Physic

    Multi-layered Ruthenium-modified Bond Coats for Thermal Barrier Coatings

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    Diffusional approaches for fabrication of multi-layered Ru-modified bond coats for thermal barrier coatings have been developed via low activity chemical vapor deposition and high activity pack aluminization. Both processes yield bond coats comprising two distinct B2 layers, based on NiAl and RuAl, however, the position of these layers relative to the bond coat surface is reversed when switching processes. The structural evolution of each coating at various stages of the fabrication process has been and subsequent cyclic oxidation is presented, and the relevant interdiffusion and phase equilibria issues in are discussed. Evaluation of the oxidation behavior of these Ru-modified bond coat structures reveals that each B2 interlayer arrangement leads to the formation of α-Al 2 O 3 TGO at 1100°C, but the durability of the TGO is somewhat different and in need of further improvement in both cases

    Investigating the Influence of High-Speed Gantry Rotation in Cardiac CT on Motion Artifacts in Aortic Stenosis Patients Not Premedicated with β-Blockers: The FAST-CCT Randomized Trial Protocol.

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    Coronary CT angiography (CCTA) is increasingly used as a non-invasive tool to assess coronary artery disease (CAD). However, CCTA is subject to motion artifacts, potentially limiting its clinical utility. Despite faster (0.35 and 0.28 s/rot) gantry rotation times, low (60-65 bpm) heartbeat is recommended, and the use of β-blockers is often needed. Technological advancements have resulted in the development of faster rotation speeds (0.23 s/rot). However, their added value in patients not premedicated with β-blockers remains unclear. This prospective single-center, two-arm, randomized, controlled trial aims to assess the influence of fast rotation on coronary motion artifacts, diagnostic accuracy of CCTA for CAD, and patient safety. We will randomize a total of 142 patients aged ≥ 50 scheduled for an aortic stenosis work-up to receive CCTA with either a fast (0.23) or standard (0.28 s/rot) gantry speed. rate of CCTAs with coronary motion artifacts hindering interpretation. assessable coronary segments rate, diagnostic accuracy against invasive coronary angiography (ICA), motion artifact magnitude per segment, contrast-to-noise ratio (CNR), and patient ionizing radiation dose. The local ethics committee has approved the protocol. Potential significance: FAST-CCT may improve motion artifact reduction and diagnosis quality, thus eliminating the need for rate control and β-blocker administration. gov identifier: NCT05709652
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