Human musical capacity and products should have been induced by the hominin-specific combination of several biosocial features: A three-phase scheme on socio-ecological, cognitive, and cultural evolution.

Various selection pressures have shaped human uniqueness, for instance, music. When and why did musical universality and diversity emerge? Our hypothesis is that "music" initially originated from manipulative calls with limited musical elements. Thereafter, vocalizations became more complex and flexible along with a greater degree of social learning. Finally, constructed musical instruments and the language faculty resulted in diverse and context-specific music. Music precursors correspond to vocal communication among nonhuman primates, songbirds, and cetaceans. To place this scenario in hominin history, a three-phase scheme for music evolution is presented herein. We emphasize (1) the evolution of sociality and life history in australopithecines, (2) the evolution of cognitive and learning abilities in early/middle Homo, and (3) cultural evolution, primarily in Homo sapiens. Human musical capacity and products should be due to the hominin-specific combination of several biosocial features, including bipedalism, stable pair bonding, alloparenting, expanded brain size, and sexual selection.

A panel data analysis of the probability of childbirth in a Japanese sample: New evidence of the two-child norm.

OBJECTIVES: To reveal the conditions that could facilitate childbirth in modern humans, it is necessary to analyze not only cross-sectional surveys but also panel data that track the same person for a long period. In this study, we analyzed factors that would influence the probability of childbirth. METHODS: We analyzed Japanese panel data with a Cox proportional hazard model. Subjects of our analysis were married women and their childbirth records from 2004 to 2009. RESULTS: Contrary to the predictions based on the theory of behavioral ecology, we found no positive relationship between good parental conditions for childcare, such as high income, increase in income, or coresidence with parents (i.e., grandparents of children), and the occurrence of childbirth. We found that the number of existing children had a significant impact on the probability of childbirth. The likelihood of further childbirth by couples with one child was nearly equal to that of childless ones. However, the corresponding likelihood of couples with two children was about five times lower than that of childless ones. CONCLUSIONS: The total fertility rates in modern developed societies are quite low and couples prefer having two children. This trend is known as the two-child norm, but it is a paradoxical phenomenon in terms of fitness maximization. Our result provided new quantitative evidence of this norm. This study revealed that the number of existing children being less than two was one of the factors associated with further childbearing in our Japanese sample.

Childcare support and child social development in Japan: investigating the mediating role of parental psychological condition and parenting style.

In humans, support from partners and alloparents is crucial for successful child-rearing and optimal child development. However, the complex relationships among childcare support, children's outcomes and parental characteristics have not been fully examined. We investigate how three sources of partner and alloparental support-partner's childcare participation, support from children's grandparents and support from non-kin-can be associated with child social development. We hypothesize that the associations between childcare support from partners/alloparents and child social development are partly mediated by parental psychological condition and parenting style. To test this, we conducted path analyses on online survey data collected in 2016 from parents of 3- to 5-year-old children in Japan. We found no evidence that childcare support had direct positive effects on child social development. Rather, the benefit of childcare support was mediated by its effects on parental psychological condition and parenting style, which in turn improved children's outcomes. At the same time, we found some evidence that greater availability of childcare support was directly associated with more behavioural difficulties in children. Our findings reveal the complex pathways between childcare support, parental characteristics and children's outcomes in Japan, showing potential mechanisms behind parental and alloparental effects in industrialized populations. This article is part of the theme issue 'Multidisciplinary perspectives on social support and maternal-child health'.

Simple PEG conjugation of SPIO via an Au-S bond improves its tumor targeting potency as a novel MR tumor imaging agent.

Gold/iron oxide magnetic nanoparticles are hybrid nanoparticles containing a core of magnetic iron oxide and surface colloidal gold, which allows for various biomaterials to be immobilized on the surface of the iron oxide nanoparticles via colloidal gold. Here, we developed a novel magnetic resonance (MR) imaging agent to broaden the MR tumor-imaging spectrum of superparamagnetic iron oxide nanoparticles (SPIO), e.g., Feridex(), a clinical MR imaging agent for diagnosing liver cancer. Au/Feridex was synthesized by electron beam irradiation, and thiol-modified poly(ethylene glycol) (PEG-SH) was easily conjugated to its surface via an Au-S bond without the need for any chemical reactions. PEG conjugation of Au/Feridex enhanced its accumulation in Meth-A tumor tissue and decreased its accumulation in normal liver tissue. In addition, MRI using PEG-Au/Feridex, in contrast to MRI using unmodified Au/Feridex and Feridex, detected B16BL6 and Meth-A tumor tissues in vivo. This finding indicates that PEG-Au/Feridex is useful for diagnosing various types of tumors. In addition, because the synthesis of PEG-Au/Feridex is simple and high yields are easily produced, PEG-modified SPIO for tumor diagnosis can be prepared on an industrial scale with low cost.

Preparation for highly sensitive MRI contrast agents using core/shell type nanoparticles consisting of multiple SPIO cores with thin silica coating.

We describe here the facile and robust preparation methods for the multiple-SPIO-containing silica-coated core/shell type nanoparticles which can serve as a highly sensitive MRI contrast agent. The imidazolium-tethered core/shell type particles were synthesized, and the centrifugal selection for the multiple-SPIO-containing particles and the etching process to fabricate thin silica layers were carried out to improve the proton relaxivity of water tissue. We found that the synthetic particles can provide approximately 7-fold clearer contrasts than that of the particles before treatments. In addition, the particles can show good dispersibility at least for 1 week in aqueous media.

Development of a half-cell for x-ray structural analysis of liquid electrolytes in rechargeable batteries.

A half-cell of the rechargeable Li-ion battery was developed to characterize an electrolyte structure using high energy x-ray total scattering measurements in combination with a two-dimensional x-ray detector. The scattering pattern consisted of strong Bragg peaks from electrodes and diffuse scatterings from sapphire windows, in addition to a weak halo pattern from the electrolyte. By selectively removing the signals of the electrodes and windows using specific numerical procedures, we could successfully extract the structural information of the electrolyte, which was in reasonable agreement with the reference data obtained from the electrolyte in a glass capillary. The present demonstration with a half-cell is expected to shed new light on operand characterization of the electrolyte structure during charging and discharging.

Thickness-induced metal to insulator transition in Ru nanosheets probed by photoemission spectroscopy: Effects of disorder and Coulomb interaction.

We investigated the electronic structures of mono- and few-layered Ru nanosheets (N layers (L) with N = 1, ~6, and ~9) on Si substrate by ultra-violet and x-ray photoemission spectroscopies. The spectral density of states (DOS) near EF of ~6 L and 1 L is suppressed as it approaches EF in contrast to that of ~9 L, which is consistent with the Ru 3 d core-level shift indicating the reduction of the metallic conductivity. A power law g(ε) ∝ |ε - εF|α well reproduces the observed spectral DOS of ~6 L and 1 L. The evolution of the power factor α suggests that the transition from the metallic state of ~9 L to the 2-dimensional insulating state with the soft Coulomb gap of 1 L through the disordered 3-dimensional metallic state of ~6 L.

DJ-1 protects against neurodegeneration caused by focal cerebral ischemia and reperfusion in rats.

Reactive oxygen species (ROS) is massively produced in the brain after cerebral ischemia and reperfusion. It reacts strongly with cellular components, which has detrimental effects and leads to neuronal cell death. DJ-1, which was found to be the causative gene of familial Parkinson's disease PARK7, is a multifunction protein, which plays a key role in transcriptional regulation, and a molecular chaperone. In this study, we investigated the neuroprotective effect of DJ-1 against neurodegeneration caused by ischemia/reperfusion injury. Cerebral ischemia was induced in rats by 120 mins of middle cerebral artery occlusion (MCAO) using an intraluminal introduction method. The intrastriatal injection of recombinant glutathione S-transferase-tagged human DJ-1 (GST-DJ-1) markedly reduced infarct size in 2,3,5-triphenyltetrazolium chloride staining at 3 days after MCAO. In addition, we performed a noninvasive evaluation of ischemic size using magnetic resonance imaging and found a significant reduction of infarct size with the administration of GST-DJ-1. In GST-DJ-1-treated rats, behavioral dysfunction and nitrotyrosine formation were significantly inhibited. Furthermore, GST-DJ-1 markedly inhibited H(2)O(2)-mediated ROS production in SH-SY5Y cells. These results indicate that GST-DJ-1 exerts a neuroprotective effect by reducing ROS-mediated neuronal injury, suggesting that DJ-1 may be a useful therapeutic target for ischemic neurodegeneration.

Assembly system of direct modified superparamagnetic iron oxide nanoparticles for target-specific MRI contrast agents.

We report the direct modification of SPIOs with a biomolecule and the target-specific assembly system of these modified SPIOs for using MRI contrast agents. The transverse relaxation rate of the aqueous solutions containing the modified SPIOs was altered by the dispersion state.

A novel magnetic resonance-based method to measure gene expression in living cells.

In unicellular and multicellular eukaryotes, elaborate gene regulatory mechanisms facilitate a broad range of biological processes from cell division to morphological differentiation. In order to fully understand the gene regulatory networks involved in these biological processes, the spatial and temporal patterns of expression of many thousands of genes will need to be determined in real time in living organisms. Currently available techniques are not sufficient to achieve this goal; however, novel methods based on magnetic resonance (MR) imaging may be particularly useful for sensitive detection of gene expression in opaque tissues. This report describes a novel reporter gene system that monitors gene expression dynamically and quantitatively, in yeast cells, by measuring the accumulation of inorganic polyphosphate (polyP) using MR spectroscopy (MRS) or MR spectroscopic imaging (MRI). Because this system is completely non-invasive and does not require exogenous substrates, it is a powerful tool for studying gene expression in multicellular organisms, as well.

An onion farmer with a case of hypersensitivity pneumonitis caused by Aspergillus niger.

A 62-year old man was admitted to our hospital with a 2-week complaint of a dry cough, general fatigue, and dyspnea on effort. He has been an onion farmer for several years and developed these symptoms after cleaning up onion peels with air compressors. A chest roentgenogram and computed tomography showed a ground glass shadow in the bilateral upper lung field. Cellular analysis of the bronchoalveolar lavage fluid showed elevated total cell numbers and lymphocytes. Transbronchial lung biopsies revealed a non-caseating granuloma with both epithelioid cells and Langhans giant cells. After the admission, these symptoms and radiological findings gradually improved without any treatment. Then, a returning-home provocation test was positive only when he worked cleaning up onion peels with air compressors. A. niger was cultured from his workplace and black mold from the onion peels. The precipitation antibody and the antigen were both positive for Aspergillus. Therefore, we diagnosed this case as hypersensitivity pneumonitis caused by inhalation of A. niger. Although hypersensitivity pneumonia caused by A. niger is rare, physicians should aware the possibility of this condition in farmers because A niger is ubiquitously present in several vegetables and fruits.

Microglial transplantation increases amyloid-beta clearance in Alzheimer model rats.

Immunization with amyloid-beta (Abeta) peptides, a therapeutic approach in Alzheimer's disease (AD), reduces brain Abeta, and microglial Abeta phagocytosis has been proposed as an Abeta-lowering mechanism. We transplanted rat microglia into the rat lateral ventricle just after intra-hippocampal Abeta injection, and then investigated the contribution of exogenous microglia to Abeta clearance. Migration of exogenous microglia from the lateral ventricle to Abeta plaque was detected by magnetic resonance imaging and histochemical analysis, and the clearance of Abeta was increased by transplantation. These results suggest the possible usefulness of exogenous microglia to the therapeutic approach in AD.

The MR tracking of transplanted ATDC5 cells using fluorinated poly-L-lysine-CF3.

Magnetic resonance (MR) imaging using super-paramagnetic iron oxides (SPIOs) is a powerful tool to monitor transplanted cells in living animals. However, since SPIOs are negative contrast agents it is difficult to track transplanted cells in bone and cartilage that originally display low signals. In this study, we examined the feasibility of tracking with fluorescein isothiocyanate (FITC)-labeled poly-L-lysine-CF(3) (PLK-CF(3)) using mouse ATDC5 cells, a stem cell line of bone and cartilage cells. FITC-labeled PLK-CF(3) was easily internalized by ATDC5 cells by adding it into culture medium. No acute or long-term toxicities were seen at less than 160 microg/ml. Labeled cells transplanted into the cranial bone of mice were detected for at least 7 days by MR images. FITC-labeled PLK-CF(3) is a useful positive contrast agent for MR tracking in bone and cartilage.

Fluorine-19 fast recovery fast spin echo imaging for mapping 5-fluorouracil.

We investigated the effects of fast recovery (FR) to increase the sensitivity of fluorine-19 ((19)F) fast spin echo (FSE) in mapping 5-fluorouracil (5-FU) and its metabolites. We added an additional 90 degrees pulse (which flips back longitudinal magnetization at the end of the sequence) to the chemical shift selective (19)F FSE pulse sequence. In 5-FU solution, FR remarkably improved the signal-to-noise (S/N) ratio of (19)F 5-FU images, having higher effects with shorter repetition time and smaller echo train numbers. In animal studies, FR produced a conspicuous increase in (19)F signals in the urinary bladder. FR effects for (19)F signals in the liver were smaller than those in other organs but still substantial. Utilization of FR in (19)F FSE images promises more sensitive observation of (19)F metabolite maps of 5-FU and other (19)F-containing compounds that have relatively long relaxation times.

MR tracking of transplanted glial cells using poly-L-lysine-CF3.

Magnetic resonance (MR) imaging using super-paramagnetic iron oxides (SPIOs) is a powerful tool to monitor transplanted cells in living animals. Since, however, SPIOs are negative contrast agents, positive agents have been explored. In this study, we examined the feasibility of FITC-labeled poly-L-lysine-CF3 (PLK-CF3) using glial cells. FITC-labeled PLK-CF3 was easily internalized by neuroblastoma cells and glia as adding it into culture medium. No toxicity was seen at the concentration of less than 80 microg/ml. MR images positively detected labeled cells transplanted in the brain of living mouse. The results indicate that FITC-labeled PLK-CF3 is a useful positive contrast agent for MR tracking.

Magnetic resonance imaging using hemagglutinating virus of Japan-envelope vector successfully detects localization of intra-cardially administered microglia in normal mouse brain.

Although the therapeutic use of microglia has received some attention for the treatment of brain diseases, few non-invasive techniques exist for monitoring the cells after administration. Here, we present a technique using magnetic resonance imaging (MRI) to track microglia injected intra-cardially. We labeled microglia expressing enhanced green fluorescent protein with superparamagnetic iron oxide (Resovist) using the hemagglutinating virus of Japan-envelope vector. We injected labeled microglia into the left ventricle of the heart of mice. After monitoring exogenously administered microglia in the mouse brain in vivo using T(2)*-weighted MRI at a magnetic field of 7T, we compared the MR images with histochemical localization of exogenous microglia in vitro. MRI revealed clear signal changes attributable to Resovist-containing microglia in the mouse brain. Histochemistry demonstrated the presence of exogenous microglia in the brain at the same locations shown by MRI. This study demonstrates the usefulness of MRI for non-invasive monitoring of exogenous microglia, and suggests a promising future for microglia/macrophages as therapeutic tools for brain disease.

Does Sexual Conflict between Mother and Father Lead to Fertility Decline? : A Questionnaire Survey in a Modern Developed Society.

Fertility decline is a great challenge to evolutionary approaches to human behavior. In this study, we apply the perspective of sexual conflict between mother and father to the fertility decline. We predict that, under serial monogamy allowing for mate changes, the ideal number of children for women should be smaller than that for men, because the cost of reproduction for women should be higher than that for men. Our reasoning is that if the cost of child-bearing and child-rearing is higher for women than men, and if women, who therefore would want a smaller number of children than their husbands, have gained more power in reproductive decision-making within a couple owing to the modernization of society, fertility should decline. Until now, few evolutionary studies have analyzed empirical data in modern developed societies with such a perspective. Our questionnaire survey in an urban area in Japan revealed that mothers did experience greater cost during childcare than fathers. However, in contrast to our prediction, we found no sex differences in the ideal number of children between mothers and their husbands in many cases. About 60% of parents remembered wanting two children when they were childless. Moreover, mothers and their husbands had equal power in their decision-making regarding having children. After presenting these results, we discuss some perspectives to advance our understanding of fertility decline in terms of sexual conflict.

A rapid presentation event-related functional magnetic resonance imaging study of response inhibition in macaque monkeys.

Rapid presentation event-related functional magnetic resonance imaging was applied to macaque monkeys performing a symmetrically rewarded go/no-go task, to investigate neural correlate of response inhibition. Sensorimotor activation related to the task performance was observed predominantly in the hemisphere contralateral to the response forelimb. Furthermore, no-go dominant activation possibly related to response inhibition, was observed in the ventral prefrontal cortex, in accordance with previous electrophysiological studies. These results show the feasibility of rapid presentation event-related functional magnetic resonance imaging in behaving monkeys.

Sex differences in human greeting behaviors in waiting and meeting situations: a field study in Japan.

In this study, I observed the greeting behaviors of 3,008 people or 1,504 dyads while they were waiting for and meeting another person at a station in Japan. I recorded human greeting behaviors and evaluated the factors that influenced them. I classified the greeting behaviors as body contact, wave, hail or bow. At least one of these four behaviors was observed in 43.4% of all. The greeting behaviors occurred more frequently in the person that arrived the second at the waiting location than in the first. Sex differences in greeting behaviors were also observed. For example, females waved their hands most frequently whereas males raised their hands to hail most frequently. Similarly, the greeting behaviors differed according to the sex patterns of the actors and the recipients. These findings suggest the possibility that relationship differences among male same-sex pairs, female same-sex pairs and opposite-sex pairs create sex differences in greeting behaviors like nonhuman animals.