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The tooth is mainly composed of dentin and enamel. Identification of dentin-producing odontoblasts and enamel-producing ameloblasts using reporter techniques is useful to study tooth development and regeneration with tissue engineering. Ameloblasts express Amelogenin, Ameloblastin, Enamelin, and Amelotin, whereas odontoblasts express Dentin sialophosphoprotein ( Dspp) and Dentin matrix protein1 ( Dmp1). Although there are several transgenic lines using promoter elements or bacterial artificial chromosomes (BACs) to label odontoblasts and ameloblasts, there is a possibility that the expression patterns vary from the endogenous genes. Here, we established 2 lines of mice where tdTomato was knocked into the second exon of X-chromosomal Amelogenin ( Amelx), and green fluorescent protein (GFP) was knocked into the second exon of Dspp. tdTomato and GFP were highly expressed on secretory ameloblasts and secretory and fully differentiated odontoblasts, respectively. In addition, DSPP and AMELX were not produced in the dentin matrix and enamel matrix of Dspp GFP/GFP and Amelx tdTomato male mice (as representative of AmelxtdTomato/Y hemizygous male mice), respectively. Moreover, micro–computed tomography analysis of Amelx tdTomato male mice revealed a notable reduction in enamel volume but increased dentin mineral density. Dspp GFP/GFP mice had reduced dentin mineral density. To identify odontoblasts and ameloblasts from developing tooth, we examined the expression of mesenchymal cell surface molecules CD90, CD166 and epithelial cell surface molecules CD49f, Epcam1 with fluorescence on odontoblasts and ameloblasts in these mice. We found that GFP+ odontoblasts and tdTomato+ ameloblasts in tooth germ from 0.5-d-old DsppGFP/+ mice and Amelx tdTomato male mice were enriched in CD45−/Ter119−/Epcam1−/CD90+/Integrin α4+cell fractions and CD45−/Ter119−/Epcam1+/CD49f+/CD147+ cell fractions, respectively. By using antibodies against mesenchymal and epithelial cell surface molecules and fluorescence, we can easily distinguish odontoblasts from ameloblasts and isolate each cell for further studies. These mice would serve as useful models for tooth development and regeneration as well as provide concurrent observation for the differentiation processes of odontoblasts and ameloblasts in vivo and in vitro.

The development of hardware neural networks, including neuromorphic hardware, has been accelerated over the past few years. However, it is challenging to operate very large-scale neural networks with low-power hardware devices, partly due to signal transmissions through a massive number of interconnections. Our aim is to deal with the issue of communication cost from an algorithmic viewpoint and study learning algorithms for energy-efficient information processing. Here, we consider two approaches to finding spatially arranged sparse recurrent neural networks with the high cost-performance ratio for associative memory. In the first approach following classical methods, we focus on sparse modular network structures inspired by biological brain networks and examine their storage capacity under an iterative learning rule. We show that incorporating long-range intermodule connections into purely modular networks can enhance the cost-performance ratio. In the second approach, we formulate for the first time an optimization problem where the network sparsity is maximized under the constraints imposed by a pattern embedding condition. We show that there is a tradeoff between the interconnection cost and the computational performance in the optimized networks. We demonstrate that the optimized networks can achieve a better cost-performance ratio compared with those considered in the first approach. We show the effectiveness of the optimization approach mainly using binary patterns and apply it also to gray-scale image restoration. Our results suggest that the presented approaches are useful in seeking more sparse and less costly connectivity of neural networks for the enhancement of energy efficiency in hardware neural networks.

Follicular dendritic cells (FDCs) are non-hematopoietic cells that are localized in the germinal centers (GCs) of lymph nodes (LNs) and are involved in humoral immunity. FDCs are a rare population that are sensitive to mechanical and chemical stimuli, making their isolation for analysis difficult. In Peyer's Patches, which are the main IgA-inductive sites, FDCs have been reported to be activated by retinoic acid receptor (RAR) and toll-like receptor (TLR) signals to induce IgA production. However, little is known about FDCs in mesenteric LNs (MLNs), although MLNs are also an IgA-inductive site. In this study, we efficiently isolated FDCs as CD35

Simulation and experimental results of a time-delay photonic reservoir computer based on VCSEL and photodiode chips with multi-mode waveguide splitter and combiner is presented. The design is based on technology developed for a high bandwidth density optical mulit-chip module with polymer waveguides for optical interconnect applications. The number of virtual nodes in the reservoir can be adjusted by varying the feedback delay time and the input signal rate. Results on distorted signal recovery and non-linear waveform generation tasks are presented and are promising for the development of a platform for board-integrated photonic neural network architecture.

Yolk sac (YS) CSF1 receptor positive (CSF1R

Primitive erythrocytes are the first hematopoietic cells observed during ontogeny and are produced specifically in the yolk sac. Primitive erythrocytes express distinct hemoglobins compared with adult erythrocytes and circulate in the blood in the nucleated form. Hematopoietic stem cells produce adult-type (so-called definitive) erythrocytes. However, hematopoietic stem cells do not appear until the late embryonic/early fetal stage. Recent studies have shown that diverse types of hematopoietic progenitors are present in the yolk sac as well as primitive erythroblasts. Multipotent hematopoietic progenitors that arose in the yolk sac before hematopoietic stem cells emerged likely fill the gap between primitive erythropoiesis and hematopoietic stem-cell-originated definitive erythropoiesis and hematopoiesis. In this review, we discuss the cellular origin of primitive erythropoiesis in the yolk sac and definitive hematopoiesis in the fetal liver. We also describe mechanisms for developmental switches that occur during embryonic and fetal erythropoiesis and hematopoiesis, particularly focusing on recent studies performed in mice.

Background Photoreceptor degenerative diseases such as retinitis pigmentosa and age-related macular degeneration gradually proceed to photoreceptor degeneration. In animal models of photoreceptor degeneration, it is difficult to evaluate the loss of function in the retina, especially in a focal lesion. Methods To induce local lesion in rat retina, one microliter of N-Methyl-N-Nitrosourea (MNU) solution was injected subretinally into a temporal site of the retina. A week after the injection, multifocal electroretinogram (mfERG) was recorded to presume the degenerated site. Based on the data from mfERG, optical coherence tomography (OCT) was performed. After the OCT, eyes were fixed with 4% paraformaldehyde and the flat-mounted retinas were stained with peanut agglutinin (PNA) and wheat germ agglutinin (WGA). Following observation under a fluorescence microscope, the retina was embedded into an OCT compound and cryo-sections were obtained. Results The decreased responses in some divisions of the retina were detected in the recording of mf-ERGs. Most of the decreased responses were localized in the temporal part of the retina corresponding to the MNU injection site. The OCT images at the area recorded a lower response of the data from mfERG and showed the severe destruction of photoreceptors; however, a well-organized retinal structure was observed in other parts of the retina. PNA and WGA staining also showed a decreased number of cones and rods in the degenerated area. Conclusions Subretinal injection of MNU induced the local photoreceptor degeneration without effects on other retinal layers. mfERGs could detect the focal lesion, and it might be a very helpful indication to perform OCT. These methods would help the evaluation of the effects of regenerative medicine in rodents.

Neural networks in which the interconnections between the nodes are randomly assigned are promising for the realization of neuromorphic devices in which the resource requirements for training are lower than for a fully deterministic system. Reservoir computing is a class of recurrent network for which the input and internal weights are random and fixed over time, and only the output weights are trained via a linear regression. In this work, we review the recent work on photonic reservoirs and describe our recent results on the implementation of a single node system based on multi-mode optical interconnect technology developed for high channel density and low power data transfer applications. We discuss the potential advantages of this approach for the realization of a photonic cluster of reservoirs.

This study assesses the influence of particle size and spray parameters on the structural, mechanical, and electrical insulation properties of alumina coatings deposited by atmospheric plasma spraying. It has been found that the combination of a relatively fine feedstock powder and high velocity plasma spraying promotes the formation of denser coatings with high dielectric strength. Correlations between dielectric strength and deposition efficiency, coating hardness, crystal structure, and surface roughness are also assessed.

We present a framework of wave-based neuromorphic computing aiming at brain-like capabilities and efficiencies with nanoscale device integration. We take advantage of the unique nature of elastic nondissipative wave dynamics in both computations and IO communications in between as a means to natively implement and execute neuromorphic computing functions such as weighted sum in a spatiotemporal manner. Lower bound analysis based on a memory model and wave group velocity scaling is provided for conceptual evaluations.

Formation of the hematopoietic cells occurs in multiple steps. The first hematopoietic cells observed during ontogeny are primitive erythrocytes, which are produced in the early yolk sac within a limited temporal window. Multi-lineage hematopoiesis, which supplies almost the entire repertoire of blood cell lineages, lags behind primitive erythropoiesis in the tissue. However, molecular mechanisms regulating sequential generation of primitive erythrocytes and multipotent hematopoietic progenitors in the yolk sac are largely unknown. In this study, the transcription factors involved in the development of hematopoietic cells were examined in purified progenitor cell populations from pluripotent stem cell cultures and from the yolk sac of developing embryos. We found that the earliest committed hematopoietic progenitors highly expressed Gata1, Scl/tal1, and Klf1 genes. Expression of these transcription factors, which is known to form a core erythroid transcriptional network, explained the prompt generation of primitive erythrocytes from these earliest progenitors. Importantly, the multipotent hematopoietic cells, which lack the differentiation potential into primitive erythroid cells, down-regulated these genes during a transition from the earliest committed progenitors. In addition, we showed that Pu.1 is involved in the multipotent cell differentiation through the suppression of erythroid transcription program. We propose that these molecular mechanisms governed by transcription factors form sequential waves of primitive erythropoiesis and multi-lineage hematopoiesis in the early yolk sac of developing embryos. J. Cell. Physiol. 232: 323-330, 2017. © 2016 Wiley Periodicals, Inc.

The optomotor response of animals is commonly used to measure their visual performance, e.g., rats of different genetically altered strains or various drug tests. With the presentation of stimuli using computer screens or projectors, the common idea focuses on measuring the eye movement or head and/or body movement to characterize changes of the head gaze. However, traditional methods rely on either the invasive fixation of animals, or the judgment of a human observer who reports the stimulus-tracking movements. In this paper, we propose a novel head gaze determination system to automatically track the head movement of rats without artificial markers. The experiments were done to demonstrate the process of optimizing parameters in image processing. As a result, the head angle curve of the proposed method is consistent with that of ground-truth data annotated manually according to predefined rules. Hence, the proposed method provides a simple, convenient, and objective solution to automatically generate the head gaze orientations from massive amounts of recorded data for further visual performance analysis.