Behavioral experiments using ablation of the hippocampus are increasingly being used to address the hypothesis that the avian hippocampus plays a role in memory, as in mammals. However, the morphological basis of the avian hippocampus has been poorly understood. In the present study, the afferent and efferent connections of the hippocampus in the pigeon telencephalon were defined by injections, at various rostrocaudal sites, of neuronal tracers mainly into the triangular part located between its V-shaped layer of densely packed neurons. The major results obtained in the present study were as follows. 1) A topographical organization of the commissural projections was confirmed. These projections had two courses that projected to the contralateral side, one traveling through the fiber wall of the ventromedial telencephalon, which was the main path from neurons in the caudal hippocampus, and the other running down through the septohippocampal junction, which was the main path from neurons in the middle to rostral hippocampus. Both courses passed through the pallial commissure. 2) The hippocampus projected bilaterally to the septum, parahippocampal area (APH), and dorsolateral cortical area (CDL). These projections were also distributed topographically, with contralateral efferents crossing through the pallial commissure. 3) The hippocampus had ipsilateral reciprocal connections with APH, CDL, and the dorsal hyperstriatum. Septal afferents to the ipsilateral hippocampus were very small. 4) Intrinsic connections were found between the triangular part of the hippocampus and the lateral limb of the V-shaped layer of neurons. 5) The hippocampus projected ipsilaterally to the ventral basal ganglia and the fasciculus diagonalis Brocae. In sum, these connections of the hippocampus may form a neuronal circuit for the processing of spatial memory in pigeons.
The morphology of the tongue of an adult Formosan serow was examined to compare it with that of the Japanese serow by macroscopical and scanning electron microscopical observations. The tongue was 13.5 cm in length and 82 g in weight. The apex showed a U-shaped outline. There were 340 fungiform papillae and 23 vallate papillae on both sides. Filiform, fungiform, conical and vallate papillae were found. Annular pads surrounding the vallate papillae were poorly developed. No lenticular or foliate papillae were seen on the dorsal surface. These findings indicate that the tongue of the Formosan serow is smaller and less complex morphologically than that of the Japanese serow.
When quantum fluctuations destroy underlying long-range ordered states, novel quantum states emerge. Spin-liquid (SL) states of frustrated quantum antiferromagnets, in which highly correlated spins fluctuate down to very low temperatures, are prominent examples of such quantum states. SL states often exhibit exotic physical properties, but the precise nature of the elementary excitations behind such phenomena remains entirely elusive. Here, we use thermal Hall measurements that can capture the unexplored property of the elementary excitations in SL states, and report the observation of anomalous excitations that may unveil the unique features of the SL state. Our principal finding is a negative thermal Hall conductivity κ xy which the charge-neutral spin excitations in a gapless SL state of the 2D kagomé insulator volborthite Cu 3 V 2 O 7 (OH) 2 · 2H 2 O exhibit, in much the same way in which charged electrons show the conventional electric Hall effect. We find that κ xy is absent in the high-temperature paramagnetic state and develops upon entering the SL state in accordance with the growth of the short-range spin correlations, demonstrating that κ xy is a key signature of the elementary excitation formed in the SL state. These results suggest the emergence of nontrivial elementary excitations in the gapless SL state which feel the presence of fictitious magnetic flux, whose effective Lorentz force is found to be less than 1/100 of the force experienced by free electrons.spin liquid | frustrated magnetism | thermal transport S pin liquids (SLs) are novel states which can occur in a magnetic system when the underlying magnetic order gives way to quantum fluctuations (1). In such states the constituent spins are highly correlated but continue to fluctuate strongly down to temperatures much lower than the spin-interaction energy scale, J. Novel notions such as emergent gauge fields, topological order, and fractionalized excitations have been associated with collective phenomena in SLs. In particular, both experiments (2-5) and theories (6-11) suggest that SL states display many unusual properties. It has been reported, for instance, that low-energy spin excitations in organic insulators with a triangular lattice structure behave like mobile carriers in a paramagnetic metal with a Fermi surface (2, 3), in contrast with the charge degree of freedom which is gapped. A description in terms of an SL state with fractionalized spin excitations was incorporated to account for the excitation continuum signal detected in a kagomé antiferromagnet (4). A magnetization transport measurement has shown that a pyrochlore frustrated magnet exhibits the characteristics of a supercooled SL state (5). Exotic quasi-particles such as spinons (6-8), visons (9, 10), and photons (11) have been predicted theoretically. Despite these intensive activities, the precise characters of the elementary excitations in SL states remain, from an experimental point of view, to be pinned down.In conducting systems, it is the charge-transport properties...
Our previous study reported that TBL had higher efficiency than traditional style lecture. In the current study, there was no statistical difference in the examination score between flipped classroom and TBL. Therefore, we conclude that both styles are highly effective than traditional style lecture and constitute valid formats for clinical dental education.
Strongly enhanced quantum fluctuations often lead to a rich variety of quantum-disordered states. Developing approaches to enhance quantum fluctuations may open paths to realize even more fascinating quantum states. Here, we demonstrate that a coupling of localized spins with the zero-point motion of hydrogen atoms, that is, proton fluctuations in a hydrogen-bonded organic Mott insulator provides a different class of quantum spin liquids (QSLs). We find that divergent dielectric behavior associated with the approach to hydrogen-bond order is suppressed by the quantum proton fluctuations, resulting in a quantum paraelectric (QPE) state. Furthermore, our thermal-transport measurements reveal that a QSL state with gapless spin excitations rapidly emerges upon entering the QPE state. These findings indicate that the quantum proton fluctuations give rise to a QSL—a quantum-disordered state of magnetic and electric dipoles—through the coupling between the electron and proton degrees of freedom.
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