Facial expression recognition of a speaker using thermal image processing and reject criteria in feature vector space

In our previously developed method for the facial expression recognition of a speaker, the positions of feature vectors in the feature vector space in image processing were generated with imperfections. The imperfections, which caused misrecognition of the facial expression, tended to be far from the center of gravity of the class to which the feature vectors belonged. In the present study, to omit the feature vectors generated with imperfections, a method using reject criteria in the feature vector space was applied to facial expression recognition. Using the proposed method, the facial expressions of two subjects were discriminable with 86.8 % accuracy for the three facial expressions of “happy”, “neutral”, and “others” when they exhibited one of the five intentional facial expressions of “angry”, “happy”, “neutral”, “sad”, and “surprised”, whereas these expressions were discriminable with 78.0 % accuracy by the conventional method. Moreover, the proposed method effectively judged whether the training data were acceptable for facial expression recognition at the moment.     

Natriuretic peptide family as a novel antimigration factor of vascular smooth muscle cells

Vascular smooth muscle cell (SMC) migration is proposed to be an important process in the initiation and/or progression of atherosclerosis. The present study examined the effects of the natriuretic peptide family (atrial, brain, and C-type natriuretic peptides; ANP, BNP, and CNP) on the migration of cultured rat SMCs, using Boyden's chamber methods. Fetal calf serum (FCS) and platelet-derived growth factor (PDGF)-BB potently stimulated SMC migration. Rat ANP(1-28), rat BNP-45, and rat CNP-22 clearly inhibited SMC migration stimulated with FCS or PDGF-BB in a concentration-dependent manner. CNP-22 had the most potent inhibitory effect compared with other natriuretic peptides. When PDGF-BB-induced migration was separated into chemotactic and chemokinetic activities, the chemotactic component was strongly inhibited by these natriuretic peptides. Such inhibition by these natriuretic peptides was paralleled by an increase in the cellular level of cyclic GMP. The addition of a cyclic GMP analogue, 8-bromo cyclic GMP, and an activator of the cytosolic guanylate cyclase, sodium nitroprusside, significantly inhibited FCS- and PDGF-BB-stimulated migration in a concentration-dependent manner. These results suggest that natriuretic peptides, especially CNP-22, inhibit FCS- or PDGF-BB-stimulated SMC migration at least in part through a cyclic GMP-dependent process. Thus, the natriuretic peptide family may play a role as an antimigration factor of SMCs under certain circumstances.     

Temporal brain imaging by a rapid scan ESR-CT system in rats receiving intraperitoneal injection of a methyl ester nitroxide radical

We performed in vivo ESR-CT (electron spin resonance-computed tomography) on rats' heads, in which the blood-brain barrier-permeable nitroxide radical, 3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (PCAM) was injected intraperitoneally, using a rapid scan ESR-CT system operating at 700 MHz. In a spatiotemporal study we found that different regions of the brain showed differences in the rate of decay of the radical. Repeated injection of PCAM gave clear ESR-CT images of the brain. We think that the present method is useful for evaluating the capacity to eliminate exogenous free radicals in some parts of the brain.     

In vivo analysis of hydrogen peroxide and lipid radicals in the striatum of rats under long-term administration of a neuroleptic

It has been hypothesized that free radicals play a causative role in tardive dyskinesia, which is an inveterate movement disorder caused by chronic administration of neuroleptics. To verify this hypothesis, rats were reared while being regularly treated with water containing a neuroleptic, haloperidol (HPD), for 1 year (HPD group). The changes in the striatal hydrogen peroxide content of the rats in the HPD and control groups were measured by using a Pt-disk microelectrode while the animals were in a freely moving state following intraperitoneal administration of HPD (HPD challenge). We also performed electron spin resonance (ESR) detection of lipid radicals in the striatum before the HPD challenge. HPD challenge led to significant elevation of the intrastriatal hydrogen peroxide in all animals, but the elevation in the HPD group was smaller than that in the control group. However, in the HPD group, marked ESR signals of intrastriatal lipid radicals were observed. We think that these results support the hypothesis on the role of free radicals in tardive dyskinesia.     

Dopamine as a novel antimigration and antiproliferative factor of vascular smooth muscle cells through dopamine D1-like receptors

Vascular smooth muscle cell (VSMC) migration and proliferation are believed to play key roles in atherosclerosis. To elucidate the role of vascular dopamine D1-like receptors in atherosclerosis, the effects of dopamine and specific D1-like agonists SKF 38,393 and YM 435 on platelet-derived growth factor (PDGF) BB-mediated VSMC migration and proliferation were studied. We observed that cells stimulated by PDGF-BB (5 ng/mL), showed increased migration and proliferation. These effects were prevented by coincubation with dopamine, SKF 38,393, or YM 435 (1 to 10 mumol/L), and this prevention was reversed by Sch 23,390 (1 to 10 mumol/l), a specific D1-like antagonist. These actions are mimicked by forskolin (1 to 10 mumol/L), a direct activator of adenylate cyclase and 8-bromo-cAMP at 0.1 to 1 mmol/L and are blocked by a specific protein kinase A inhibitor, N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinoline-sulfonamide (H 89), but not blocked by its negative control, N-[2-(N-formyl)-p-chlorociannamylamino)ethyl]-5-isoquinoline sulfonamide (H 85). PDGF-BB (5 ng/mL)-mediated activation of phospholipase D, protein kinase C, and mitogen activated protein kinase activity were significantly suppressed by coincubation with dopamine. These results suggest that vascular D1-like receptor agonists inhibit migration and proliferation of VSMC, possibly through protein kinase A activation and suppression of activated phospholipase D, protein kinase C, and mitogen-activated protein kinase activity.     

Hydrodynamic vertical rotation method for a single cell in an open space

Rotation of a single cell is an indispensable cell manipulation technique for genetic studies and clinical applications. Conventional contact manipulation methods for rotation of a cell use complex control systems and tools, while conventional non-contact manipulation methods have limitations regarding the operating space or range of the rotated cell size. Here, we report on a convenient, non-contact, and open space method for a wide range of single cell sizes (micrometer scale to millimeter scale) rotating in a vertical plane (out-of-plane) of an open space. This method uses a vertical microscale recirculation zone for capturing and rotating the cell. We fabricated a micro-orifice on the surface of a microfluidic chip to generate the micro-recirculation zone and then carried out experiments on vertical rotations of Xenopus oocyte, embryoid body, brine shrimp oocyte, and zebrafish oocyte using this chip. We demonstrated the rotation of four types of cells in the vertical plane between the air–liquid interface and the top surface of the microfluidic chip; then, we conducted a simulation to analyze the dynamics of the vertical rotation of the Xenopus oocyte qualitatively. Our results indicated rotation speed of the four types of cells was controllable by the micro-recirculation zone. The size and density of oocytes also affected the process of capturing and rotation. We expect this method opens new research opportunities in three-dimensional cell manipulation, imaging, and analysis.     

A smooth signal generator based on quadratic B-spline functions

A hardware system of quadratic spline interpolation is proposed. Its properties are that switching noise with digital-to-analog (D-A) converter chips does not appear and that the output is smooth without any analog lowpass filters that disorganize the phase characteristics     

Differential cross sections of neutron-induced fragment-emission reactions for a microdosimetry study

Experimental differential cross sections of fragment emission (p, d, t, alpha, Li, Be and B), which were obtained for tens of mega electron volt neutrons on carbon and aluminum, using a counter telescope array and a Bragg-curve counter specially developed for neutron-induced reactions, are presented and compared with theoretical calculations using various reaction models. A calculation with the ISOBAR and GEM models was found to reproduce the experimental data except for an underestimation in non-vaporation processes. Calculations of the energy deposition by neutrons in a thin silicon layer show significant differences among the model employed.