Nonlocal Spin Correlation as a Signature of Ising Anyons Trapped in Vacancies of the Kitaev Spin Liquid.

In the Kitaev chiral spin liquid, Ising anyons are realized as Z_{2} fluxes binding Majorana zero modes, which, however, are thermal excitations with finite decay rates. On the other hand, a lattice vacancy traps a Z_{2} flux even in the ground state, resulting in the stable realization of a Majorana zero mode in a vacancy. We demonstrate that spin-spin correlation functions between two vacancy sites exhibit long-range correlation arising from the fractionalized character of Majorana zero modes, in spite of the strong decay of bulk spin correlations. Remarkably, this nonlocal spin correlation does not decrease as the distance between two vacancy sites increases, signaling Majorana teleportation. Furthermore, we clarify that the nonlocal correlation can be detected electrically via the measurement of nonlocal conductance between two vacancy sites, which is straightforwardly utilized for the readout of Majorana qubits. These findings pave the way to the measurement-based quantum computation with Ising anyons trapped in vacancies of the Kitaev spin liquid.

Spin-Nernst Effect in Time-Reversal-Invariant Topological Superconductors.

We investigate the spin-Nernst effect in time-reversal-invariant topological superconductors, and show that it provides smoking-gun evidence for helical Cooper pairs. The spin-Nernst effect stems from asymmetric, in spin space, scattering of quasiparticles at nonmagnetic impurities, and generates a transverse spin current by the temperature gradient. Both the sign and the magnitude of the effect sensitively depend on the scattering phase shift at impurity sites. Therefore the spin-Nernst effect is uniquely suitable for identifying time-reversal-invariant topological superconducting orders.

Electric Probe for the Toric Code Phase in Kitaev Materials through the Hyperfine Interaction.

The Kitaev model is a remarkable spin model with gapped and gapless spin liquid phases, which are potentially realized in iridates and α-RuCl_{3}. In the recent experiment of α-RuCl_{3}, the signature of a nematic transition to the gapped toric code phase, which breaks the C_{3} symmetry of the system, has been observed through the angle dependence of the heat capacity. We here propose a mechanism by which the nematic transition can be detected electrically. This is seemingly impossible because J_{eff}=1/2 spins do not have an electric quadrupole moment (EQM). However, in the second-order perturbation, the virtual state with a nonzero EQM appears, which makes the nematic order parameter detectable by nuclear magnetic resonance and Mössbauer spectroscopy. The purely magnetic origin of the EQM is different from conventional electronic nematic phases, allowing the direct detection of the realization of Kitaev's toric error-correction code.

Chiral Higgs Mode in Nematic Superconductors.

Nematic superconductivity with spontaneously broken rotation symmetry has recently been reported in doped topological insulators, M_{x}Bi_{2}Se_{3} (M=Cu, Sr, Nb). Here we show that the electromagnetic (EM) response of these compounds provides a spectroscopy for bosonic excitations that reflect the pairing channel and the broken symmetries of the ground state. Using quasiclassical Keldysh theory, we find two characteristic bosonic modes in nematic superconductors: the nematicity mode and the chiral Higgs mode. The former corresponds to the vibrations of the nematic order parameter associated with broken crystal symmetry, while the latter represents the excitation of chiral Cooper pairs. The chiral Higgs mode softens at a critical doping, signaling a dynamical instability of the nematic state towards a new chiral ground state with broken time reversal and mirror symmetry. Evolution of the bosonic spectrum is directly captured by EM power absorption spectra. We also discuss contributions to the bosonic spectrum from subdominant pairing channels to the EM response.

Effects of cognitive remediation on cognitive and social functions in individuals with schizophrenia.

Individuals with schizophrenia exhibit cognitive impairments, which are related to impairments in social functions. This study investigated the effects of cognitive remediation on cognitive, social, and daily living impairment. Participants were individuals with schizophrenia between 20 and 60 years old (N = 44). Participants were randomly assigned to two groups: a cognitive remediation intervention group and a non-intervention control group. The control group was provided with conventional drug therapy and either day care or occupational therapy. The intervention group was provided with the "neuropsychological educational approach to cognitive remediation" developed by Medalia and co-workers. We assessed cognitive functions using the brief assessment of cognition in schizophrenia (BACS), and evaluated social and daily living functions using the global assessment of functioning (GAF) scale. Significant group by time interaction effects indicated that verbal memory, working memory, attention, and executive function showed significantly greater improvement at post-intervention for the intervention group than the control group. Social and daily living function also improved in the intervention group and improvements were maintained one year after intervention. These preliminary findings indicate that the combination of cognitive remediation and psychiatric rehabilitation is effective for facilitating improvements in cognitive function and social and daily living functions in individuals with schizophrenia.

Negative Thermal Magnetoresistivity as a Signature of a Chiral Anomaly in Weyl Superconductors.

We propose that the chiral anomaly of Weyl superconductors gives rise to negative thermal magnetoresistivity induced by emergent magnetic fields, which are generated by vortex textures of order parameters or lattice strain. We establish this scenario by combining the argument based on Berry curvatures and the quasiclassical theory of the Eilenberger equation with quantum corrections arising from inhomogeneous structures. It is found that the chiral anomaly contribution of the thermal conductivity exhibits characteristic temperature dependence, which can be a smoking-gun signature of this effect.

Duplication and Variation in the Major Histocompatibility Complex Genes in Blakiston's Fish Owl, Bubo blakistoni.

The major histocompatibility complex (MHC) includes many genes that are essential for the adaptive immune system, and variation in the antigen binding site (ABS) is related to resistance against pathogens. In the present study, quantitative real-time PCR indicated a larger number of MHC gene copies in the endangered population of Blakiston's fish owl (Bubo blakistoni) than in five other owl species, and massively parallel pyrosequencing detected more MHC class IIß per individual alleles in B. blakistoni than in the other species. A chromosomal fluorescence in situ hybridization (FISH) analysis showed that the MHC class I and class IIß loci are closely linked on a single pair of microchromosomes, indicating that the MHC genes were tandemly duplicated in a limited chromosomal region. Because B. blakistoni has twice as many MHC genes as its sister species, the tawny fish owl (Bubo flavipes), the duplication of MHC genes occurred after these species diverged by speciation. A Bayesian molecular phylogenetic analysis showed that the DAB1 and DAB2 lineages of MHC class IIß alleles from various strigid species each formed a separate clade, indicating that the two allelic lineages preceded the radiation of Strigidae and evolved as paralogs. By contrast, the ABS sequences did not form distinct clades between DAB1 and DAB2 alleles but were intermixed, presumably due to gene conversion. Despite the low diversity of alleles per locus, B. blakistoni had many lineages of MHC class IIß alleles. Gene duplication increases variation in the MHC genes in this species, and could have facilitated adaptation in small populations.

Torsional Chiral Magnetic Effect in a Weyl Semimetal with a Topological Defect.

We propose a torsional response raised by a lattice dislocation in Weyl semimetals akin to a chiral magnetic effect; i.e., a fictitious magnetic field arising from a screw or edge dislocation induces a charge current. We demonstrate that, in sharp contrast to the usual chiral magnetic effect that vanishes in real solid state materials, the torsional chiral magnetic effect exists even for realistic lattice models, which implies the experimental detection of the effect via superconducting quantum interference device or nonlocal resistivity measurements in Weyl semimetal materials.

Characterization of a topological Mott insulator in one dimension.

We investigate properties of a topological Mott insulator in one dimension by examining the bulk topological invariant and the entanglement spectrum of a correlated electron model. We clarify how gapless edge states in a noninteracting topological band insulator evolve into spinon edge states in a topological Mott insulator. Furthermore, we propose a topological Mott transition, which is a new type of topological phase transition which has never been observed in free fermion systems. This unconventional transition occurs in spin liquid phases in the Mott insulator and is accompanied by zeros of the single-electron Green's function and a gap closing in the spin excitation spectrum.

Automated neuronal reconstruction with super-multicolour Tetbow labelling and threshold-based clustering of colour hues.

Fluorescence imaging is widely used for the mesoscopic mapping of neuronal connectivity. However, neurite reconstruction is challenging, especially when neurons are densely labelled. Here, we report a strategy for the fully automated reconstruction of densely labelled neuronal circuits. Firstly, we establish stochastic super-multicolour labelling with up to seven different fluorescent proteins using the Tetbow method. With this method, each neuron is labelled with a unique combination of fluorescent proteins, which are then imaged and separated by linear unmixing. We also establish an automated neurite reconstruction pipeline based on the quantitative analysis of multiple dyes (QDyeFinder), which identifies neurite fragments with similar colour combinations. To classify colour combinations, we develop unsupervised clustering algorithm, dCrawler, in which data points in multi-dimensional space are clustered based on a given threshold distance. Our strategy allows the reconstruction of neurites for up to hundreds of neurons at the millimetre scale without using their physical continuity.

A combined small cell lung carcinoma patient with only small cell carcinoma components in mediastinal lymph node metastasis and chondrosarcoma-like components in liver metastasis.

A 69-year-old ex-smoker Japanese man presented with a left mediastinal lymph node and left upper lobe tumour. Bronchoscopic biopsy specimens from the enlarged left mediastinal lymph node and left upper lobe tumour revealed small cell lung carcinoma (SCLC). He was treated with first-line chemotherapy with carboplatin, etoposide, and atezolizumab for four courses and subsequent atezolizumab maintenance therapy. However, his left upper lobe lung tumour only increased in size, and left upper lobectomy revealed combined SCLC (adenocarcinoma and chondrosarcoma-like features). Four months after lobectomy, liver metastasis of chondrosarcoma-like features (similar to pathological findings of the left upper lobe tumour) were observed. Combined SCLC, including sarcomatous components, is rare and poorly responds to chemotherapy. The metastases of combined SCLC in this patient were of only one type of histological component, making diagnosis and treatment difficult. If treatment for SCLC responds inadequately, considering combined SCLC and actively re-examining histological diagnosis is necessary.

Electromagnetic and thermal responses of Z topological insulators and superconductors in odd spatial dimensions.

The relation between bulk topological invariants and experimentally observable physical quantities is a fundamental property of topological insulators and superconductors. In the case of chiral symmetric systems in odd spatial dimensions such as time-reversal invariant topological superconductors and topological insulators with sublattice symmetry, this relation has not been well understood. We clarify that the winding number which characterizes the bulk Z nontriviality of these systems can appear in electromagnetic and thermal responses in a certain class of heterostructure systems. It is also found that the Z nontriviality can be detected in the bulk "chiral polarization," which is induced by magnetoelectric effects.

Microglia Are Dispensable for Developmental Dendrite Pruning of Mitral Cells in Mice.

During early development, neurons in the brain often form excess synaptic connections. Later, they strengthen some connections while eliminating others to build functional neuronal circuits. In the olfactory bulb, a mitral cell initially extends multiple dendrites to multiple glomeruli but eventually forms a single primary dendrite through the activity-dependent dendrite pruning process. Recent studies have reported that microglia facilitate synapse pruning during the circuit remodeling in some systems. It has remained unclear whether microglia are involved in the activity-dependent dendrite pruning in the developing brains. Here, we examined whether microglia are required for the developmental dendrite pruning of mitral cells in mice. To deplete microglia in the fetal brain, we treated mice with a colony-stimulating factor 1 receptor (CSF1R) inhibitor, PLX5622, from pregnancy. Microglia were reduced by >90% in mice treated with PLX5622. However, dendrite pruning of mitral cells was not significantly affected. Moreover, we found no significant differences in the number, density, and size of excitatory synapses formed in mitral cell dendrites. We also found no evidence for the role of microglia in the activity-dependent dendrite remodeling of layer 4 (L4) neurons in the barrel cortex. In contrast, the density of excitatory synapses (dendritic spines) in granule cells in the olfactory bulb was significantly increased in mice treated with PLX5622 at postnatal day (P) 6, suggesting a role for the regulation of dendritic spines. Our results indicate that microglia do not play a critical role in activity-dependent dendrite pruning at the neurite level during early postnatal development in mice.

Effective Hand Rearing of Neonatal Mice for Developmental Studies.

Chronic manipulation in neonatal mice is a technical challenge, but it can achieve greater insights into how mice develop immediately after birth. However, these manipulations can often result in maternal rejection and consequently serious malnourishment and occasional death. Here, we describe a method to effectively hand rear mice to develop normally during the first post-natal week. In our experiments, we were able to negate the feeding deficiencies of anosmic mutant mice when compared to littermate controls. As a result, the delayed neuronal remodeling seen in maternally reared mutant mice was not seen in the hand-reared mutant mice. This methodology is user intensive but can be useful for a broad range of studies either requiring many interventions or one intervention that can result in maternal rejection or being outcompeted by healthy littermates.

Activity-dependent local protection and lateral inhibition control synaptic competition in developing mitral cells in mice.

In developing brains, activity-dependent remodeling facilitates the formation of precise neuronal connectivity. Synaptic competition is known to facilitate synapse elimination; however, it has remained unknown how different synapses compete with one another within a post-synaptic cell. Here, we investigate how a mitral cell in the mouse olfactory bulb prunes all but one primary dendrite during the developmental remodeling process. We find that spontaneous activity generated within the olfactory bulb is essential. We show that strong glutamatergic inputs to one dendrite trigger branch-specific changes in RhoA activity to facilitate the pruning of the remaining dendrites: NMDAR-dependent local signals suppress RhoA to protect it from pruning; however, the subsequent neuronal depolarization induces neuron-wide activation of RhoA to prune non-protected dendrites. NMDAR-RhoA signals are also essential for the synaptic competition in the mouse barrel cortex. Our results demonstrate a general principle whereby activity-dependent lateral inhibition across synapses establishes a discrete receptive field of a neuron.

Spin nematic state as a candidate of the hidden order phase of URu2Si2.

Motivated by the recent discovery of broken fourfold symmetry in the hidden order phase of URu2Si2 [R. Okazaki et al., Science 331, 439 (2011)], we examine a scenario of a spin nematic state as a possible candidate of the hidden order phase. We demonstrate that the scenario naturally explains most of experimental observations, and furthermore, reproduces successfully the temperature dependence of the spin anisotropy detected by the above-mentioned experiment in a semiquantitative way. This result provides strong evidence for the realization of the spin nematic order.

Plexin-B1 is a GTPase activating protein for M-Ras, remodelling dendrite morphology.

Plexins are receptors for axonal guidance molecules known as semaphorins. We recently reported that the semaphorin 4D (Sema4D) receptor, Plexin-B1, induces axonal growth cone collapse by functioning as an R-Ras GTPase activating protein (GAP). Here, we report that Plexin-B1 shows GAP activity for M-Ras, another member of the Ras family of GTPases. In cortical neurons, the expression of M-Ras was upregulated during dendritic development. Knockdown of endogenous M-Ras-but not R-Ras-reduced dendritic outgrowth and branching, whereas overexpression of constitutively active M-Ras, M-Ras(Q71L), enhanced dendritic outgrowth and branching. Sema4D suppressed M-Ras activity and reduced dendritic outgrowth and branching, but this reduction was blocked by M-Ras(Q71L). M-Ras(Q71L) stimulated extracellular signal-regulated kinase (ERK) activation, inducing dendrite growth, whereas Sema4D suppressed ERK activity and down-regulation of ERK was required for a Sema4D-induced reduction of dendrite growth. Thus, we conclude that Plexin-B1 is a dual functional GAP for R-Ras and M-Ras, remodelling axon and dendrite morphology, respectively.

[The effects of Tai-chi exercise for the prevention of long-term care in community-dwelling frail elderly people -new care-need certification and mortality-].

AIM: The purpose of this study was to examine the effects of a Tai Chi Yuttari-exercise based care prevention program aimed at frail elderly people on new care-need certification and mortality. METHODS: Participants were elderly individuals (≥65 years of age) who lived in Kitakata City and who had experienced a fall in the past year but were not receiving support or long-term care. Those who agreed to participate in the exercise program were the intervention group (n=34), and those who did not participate were the control group (n=84). The intervention program was carried out once a week for a total of 15 times during the period spanning December 5, 2006 to March 22, 2007. In the intervention group we measured and analyzed changes in physical functions and administered a questionnaire before and after the intervention. We confirmed any deaths and determined whether certification for long-term care had been issued to the participants, in March 2010. RESULTS: New care-need certification was issued to 2 participants (6.3%) in the intervention group and 19 (24.1%) in the control group. Logistic regression analysis revealed that participants in the intervention group tended to require less new certification than those in the control group (p=0.098). There was no significant difference in the number of deaths between the intervention (2 participants; 5.9%) and control (5 participants; 6.0%) groups. We observed significant changes between pre- and post-intervention on several variables, including motor fitness scale, maximum walking speed over 10 meters, functional reach test, ability to stand after a long period of sitting, and maximum one step width. CONCLUSION: The Tai Chi Yuttari-exercise based intervention program for frail elderly people reduced the need for new care-need certification and was useful as a care prevention program.

Post hoc Correction of Chromatic Aberrations in Large-Scale Volumetric Images in Confocal Microscopy.

Over the last decade, tissue-clearing techniques have expanded the scale of volumetric fluorescence imaging of the brain, allowing for the comprehensive analysis of neuronal circuits at a millimeter scale. Multicolor imaging is particularly powerful for circuit tracing with fluorescence microscopy. However, multicolor imaging of large samples often suffers from chromatic aberration, where different excitation wavelengths of light have different focal points. In this study, we evaluated chromatic aberrations for representative objective lenses and a clearing agent with confocal microscopy and found that axial aberration is particularly problematic. Moreover, the axial chromatic aberrations were often depth-dependent. Therefore, we developed a program that is able to align depths for different fluorescence channels based on reference samples with fluorescent beads or data from guide stars within biological samples. We showed that this correction program can successfully correct chromatic aberrations found in confocal images of multicolor-labeled brain tissues. Our simple post hoc correction strategy is useful to obtain large-scale multicolor images of cleared tissues with minimal chromatic aberrations.

BMPR-2 gates activity-dependent stabilization of primary dendrites during mitral cell remodeling.

Developing neurons initially form excessive neurites and then remodel them based on molecular cues and neuronal activity. Developing mitral cells in the olfactory bulb initially extend multiple primary dendrites. They then stabilize single primary dendrites while eliminating others. However, the mechanisms underlying selective dendrite remodeling remain elusive. Using CRISPR-Cas9-based knockout screening combined with in utero electroporation, we identify BMPR-2 as a key regulator for selective dendrite stabilization. Bmpr2 knockout and its rescue experiments show that BMPR-2 inhibits LIMK without ligands and thereby permits dendrite destabilization. In contrast, the overexpression of antagonists and agonists indicates that ligand-bound BMPR-2 stabilizes dendrites, most likely by releasing LIMK. Using genetic and FRET imaging experiments, we demonstrate that free LIMK is activated by NMDARs via Rac1, facilitating dendrite stabilization through F-actin formation. Thus, the selective stabilization of primary dendrites is ensured by concomitant inputs of BMP ligands and neuronal activity.