A three-dimensional (3D) topological insulator features a 2D surface state consisting of a single linearly dispersive Dirac cone1–3. Under broken time-reversal symmetry, the single Dirac cone is ...predicted to cause half-integer quantization of Hall conductance, which is a manifestation of the parity anomaly in quantum field theory1–9. However, despite various observations of quantization phenomena10–15, the half-integer quantization has not been observed because most experiments simultaneously measure a pair of equivalent Dirac cones16 on two opposing surfaces. Here we demonstrate the half-integer quantization of Hall conductance in a synthetic heterostructure termed a semi-magnetic topological insulator, where only one surface state is gapped by magnetic doping and the opposite one is non-magnetic and gapless. We observe half-quantized Faraday and Kerr rotations with terahertz magneto-optical spectroscopy and half-quantized Hall conductance in transport at zero magnetic field. Our results suggest a condensed-matter realization of the parity anomaly4–9 and open a way for studying the physics enabled by a single Dirac fermion.An electron with a linear dispersion relation should contribute half of a quantum of Hall conductance and thereby manifest the parity anomaly. This is demonstrated in a heterostructure of topological insulator materials.
Cooperation is central to human communication 1–3. The foundation of cooperative verbal communication is taking turns to speak. Given the universality of turn-taking 4, it is natural to ask how it ...evolved. We used marmoset monkeys to explore whether another primate species exhibits cooperative vocal communication by taking turns. Marmosets share with humans a cooperative breeding strategy and volubility. Cooperative care behaviors are thought to scaffold prosocial cognitive processes 5, 6. Moreover, marmosets and other callitrichid primates are very vocal and readily exchange vocalizations with conspecifics 7–11. By measuring the natural statistics of marmoset vocal exchanges, we observed that they take turns in extended sequences and show that this vocal turn-taking has as its foundation dynamics characteristic of coupled oscillators—one that is similar to the dynamics proposed for human conversational turn-taking 12. As marmoset monkeys are on a different branch of the evolutionary tree that led to humans, our data demonstrate convergent evolution of vocal cooperation. Perhaps more importantly, our data offer a plausible alternative scenario to “gestural origin” hypotheses for how human cooperative vocal communication could have evolved.
•Marmoset monkeys have a conversational rule that seems to require self-monitoring•Like humans, marmosets coordinate and entrain their vocal exchanges with each other•During turn-taking, marmosets behave like loosely coupled oscillators
Abstract
The Weyl semimetal (WSM), which hosts pairs of Weyl points and accompanying Berry curvature in momentum space near Fermi level, is expected to exhibit novel electromagnetic phenomena. ...Although the large optical/electronic responses such as nonlinear optical effects and intrinsic anomalous Hall effect (AHE) have recently been demonstrated indeed, the conclusive evidence for their topological origins has remained elusive. Here, we report the gigantic magneto-optical (MO) response arising from the topological electronic structure with intense Berry curvature in magnetic WSM Co
3
Sn
2
S
2
. The low-energy MO spectroscopy and the first-principles calculation reveal that the interband transitions on the nodal rings connected to the Weyl points show the resonance of the optical Hall conductivity and give rise to the giant intrinsic AHE in dc limit. The terahertz Faraday and infrared Kerr rotations are found to be remarkably enhanced by these resonances with topological electronic structures, demonstrating the novel low-energy optical response inherent to the magnetic WSM.
Functional microRNAs (miRNAs) in exosomes have been recognised as potential stable biomarkers in cancers. The aim of this study is to identify specific miRNAs in exosome as serum biomarkers for the ...early detection of recurrence in human colorectal cancer (CRC).
Serum samples were sequentially obtained from six patients with and without recurrent CRC. The miRNAs were purified from exosomes, and miRNA microarray analysis was performed. The miRNA expression profiles and copy number aberrations were explored using microarray and array CGH analyses in 124 CRC tissues. Then, we validated exosomal miRNAs in 2 serum sample sets (90 and 209 CRC patients) by quantitative real-time RT-PCR.
Exosomal miR-17-92a cluster expression level in serum was correlated with the recurrence of CRC. Exosomal miR-19a expression levels in serum were significantly increased in patients with CRC as compared with healthy individuals with gene amplification. The CRC patients with high exosomal miR-19a expression showed poorer prognoses than the low expression group (P<0.001).
Abundant expression of exosomal miR-19a in serum was identified as a prognostic biomarker for recurrence in CRC patients.
The interplay of light and magnetism allowed light to be used as a probe of magnetic materials. Now the focus has shifted to use polarized light to alter or manipulate magnetism. Here, we demonstrate ...optical control of ferromagnetic materials ranging from magnetic thin films to multilayers and even granular films being explored for ultra-high-density magnetic recording. Our finding shows that optical control of magnetic materials is a much more general phenomenon than previously assumed and may have a major impact on data memory and storage industries through the integration of optical control of ferromagnetic bits.
For over half a century now, primate vocalizations have been thought to undergo little or no experience-dependent acoustic changes during development 1. If any changes are apparent, then they are ...routinely (and quite reasonably) attributed to the passive consequences of growth. Indeed, previous experiments on squirrel monkeys and macaque monkeys showed that social isolation 2, 3, deafness 2, cross-fostering 4 and parental absence 5 have little or no effect on vocal development. Here, we explicitly test in marmoset monkeys—a very vocal and cooperatively breeding species 6—whether the transformation of immature into mature contact calls by infants is influenced by contingent parental vocal feedback. Using a closed-loop design, we experimentally provided more versus less contingent vocal feedback to twin infant marmoset monkeys over their first 2 months of life, the interval during which their contact calls transform from noisy, immature calls to tonal adult-like “phee” calls 7, 8. Infants who received more contingent feedback had a faster rate of vocal development, producing mature-sounding contact calls earlier than the other twin. The differential rate of vocal development was not linked to genetics, perinatal experience, or body growth; nor did the amount of contingency influence the overall rate of spontaneous vocal production. Thus, we provide the first experimental evidence for production-related vocal learning during the development of a nonhuman primate.
•Development of marmoset contact calls is influenced by contingent parental feedback•Use of twin infants controlled for genetics, perinatal experience, and growth•This is the first experimental evidence for vocal production learning in infant monkeys
Takahashi et al. show that infant marmoset monkeys are vocal learners. In brief but almost daily sessions, infant marmoset twins were experimentally provided with high or low levels of contingent parental vocal feedback to their vocalizations. More parental feedback accelerated the transition to consistently producing mature contact calls.
Summary
Background
Exertional heat illness (EHI) is recognised in horses, but few reports have investigated its risk factors.
Objectives
To identify risk factors for EHI in racehorses participating ...in flat races in Japan.
Study design
Descriptive epidemiology and retrospective unmatched case–control study.
Methods
Between 2005 and 2016, veterinary records of horses diagnosed with EHI after flat races were reviewed retrospectively and data of the months from April to September were used for a case–control study. For each case, three control horses were randomly selected from starts between April and September. Race records of horses and estimated wet‐bulb globe temperature (WBGT) indexes at the local meteorological observatory closest to the racecourse were investigated. To identify risk factors for EHI, univariable and multivariable logistic regression analysis was used.
Results
Of 194 cases during the study period, 188 cases occurred between April and September. The highest incidence risk was in July (1.1 cases per 1000 starts, 95% confidence interval 0.84–1.45). In the final multivariable model, WBGT index, sex, race distance, age and bodyweight were associated with EHI. When WBGT index exceeded 28°C, the risk of EHI was considerably higher than <20°C (OR 28.5, 14.2–62.4, P<0.001). Compared with uncastrated males, geldings (OR 4.9, 1.8–13.3, p = 0.002) and females (OR 2.4, 1.5–3.7, P<0.001) were at high risk of EHI (P<0.01). Furthermore, races of >1600 m (OR 1.8, 1.2–2.8, P = 0.002), 4‐year‐old (OR 3.5, 1.6–7.9, P = 0.002) and ≥5‐year‐old (OR 3.9, 1.8–9.2, P = 0.001) horses and horses with low bodyweight (OR per 20 kg, 0.8, 0.7–1.0, P = 0.02) were associated with increased risk of EHI.
Main limitations
The median straight‐line distance between the racecourse and the local meteorological observatory was 14.2 km (range, 1.1–28.3 km). There was a lack of objective criteria of EHI due to the retrospective nature of the study.
Conclusions
We identified specific risk factors for EHI in racehorses. These results may be useful to the equine industry for reducing EHI occurrence in racehorses.
We previously conducted gene expression microarray analyses to identify novel indicators for colorectal cancer (CRC) metastasis and prognosis from which we identified PVT-1 as a candidate gene. ...PVT-1, which encodes a long noncoding RNA, mapped to chromosome 8q24 whose copy-number amplification is one of the most frequent events in a wide variety of malignant diseases. However, PVT-1 molecular mechanism of action remains unclear.
We conducted cell proliferation and invasion assays using colorectal cancer cell lines transfected with PVT-1siRNA or negative control siRNA. Gene expression microarray analyses on these cell lines were also carried out to investigate the molecular function of PVT-1. Further, we investigated the impact of PVT-1 expression on the prognosis of 164 colorectal cancer patients by qRT-PCR.
CRC cells transfected with PVT-1 siRNA exhibited significant loss of their proliferation and invasion capabilities. In these cells, the TGF-β signalling pathway and apoptotic signals were significantly activated. In addition, univariate and multivariate analysis revealed that PVT-1 expression level was an independent risk factor for overall survival of colorectal cancer patients.
PVT-1, which maps to 8q24, generates antiapoptotic activity in CRC, and abnormal expression of PVT-1 was a prognostic indicator for CRC patients.
The relationship between cesium (Cs) adsorption on clay minerals with various expandabilities and Cs mobility in environment was investigated using sequential extraction, batch adsorption, X-ray ...diffraction (XRD), generalized adsorption model (GAM), and Cs LIII-edge extended X-ray absorption fine structure (EXAFS) analyses with molecular simulations using the density functional theory (DFT). In particular, the difference between the affinities of illite (non-expansion) and vermiculite (intermediate expansion) for Cs and the effect of humic acid (HA) addition on the Cs/clay mineral system were highlighted in this study. These two factors affect Cs mobility and bioavailability in surface soil and sediments.
The batch adsorption results showed that Cs adsorption was inhibited to some extent in the ternary clay+HA+Cs system because of (i) the blocked access of Cs to the frayed edge site (FES) and type II site inner–sphere (IS) complex in GAM by HA, and (ii) the reduced availability of the interlayer site in vermiculite. EXAFS analysis further confirmed that the adsorbed Cs in clay minerals was drastically changed by the sequential addition of HA. In addition, the dominant IS complex in the illite+Cs and illite+Cs+HA systems (in which HA was added after Cs adsorption on illite) can be converted to the outer–sphere (OS) complex largely in the illite+HA+Cs system (in which HA was added prior to Cs adsorption). These results are consistent with the sequential extraction and GAM results.
The IS complex of dehydrated Cs+ mainly formed at the FES and interlayer site on illite (non-expansion) without resulting in any illite structural changes. However, on vermiculite (intermediate expansion), the dehydrated Cs+ can be adsorbed as an IS complex associated with the siloxane group of the di-trigonal cavity in the tetrahedral SiO4 sheet. This adsorption is accompanied by collapse of the layer, which can be easily coated by HA molecules to prevent Cs fixation. However, a nearly complete OS complex was observed at the planar site of montmorillonite (large expansion). These processes were confirmed by sequential extraction, batch adsorption, XRD, and EXAFS, which clearly showed that Cs mobility in soil highly depends on clay mineral expandability, natural organic matter (NOM), and the coupling of both effects. The atomic-scale information given by EXAFS is consistent with the distribution data from adsorption experiments, GAM, sequential extraction, and DFT. These results can be used as a basis for a clearer understanding of Cs behavior in natural systems.
Polyamines are low molecular weight, aliphatic polycations found in the cells of all living organisms. Due to their positive charges, polyamines bind to macromolecules such as DNA, RNA, and proteins. ...They are involved in diverse processes, including regulation of gene expression, translation, cell proliferation, modulation of cell signalling, and membrane stabilization. They also modulate the activities of certain sets of ion channels. Because of these multifaceted functions, the homeostasis of polyamines is crucial and is ensured through regulation of biosynthesis, catabolism, and transport. Through isolation of the genes involved in plant polyamine biosynthesis and loss-of-function experiments on the corresponding genes, their essentiality for growth is reconfirmed. Polyamines are also involved in stress responses and diseases in plants, indicating their importance for plant survival. This review summarizes the recent advances in polyamine research in the field of plant science compared with the knowledge obtained in microorganisms and animal systems.
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