Measurements of transepithelial HCO3 transport in the rabbit cortical collecting duct (CCD) indicate that net HCO3 secretion becomes apparent only after the first month of life [F. M. Mehrgut, L. M. Satlin, and G. J. Schwartz, Am. J. Physiol. 259 (Renal Fluid Electrolyte Physiol. 28): F801-F808, 1990]. We used fluorescent probes and immunocytochemistry to trace the postnatal functional development of the beta-intercalated cell, the HCO3-secreting cell of the fully differentiated CCD. Throughout maturation, the beta-intercalated cell was empirically identified by its selective uptake of the pH-sensitive dye 2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein, an alkaline cell pH, apical binding to peanut agglutinin (PNA) and monoclonal antibody B63, and by its functional capacity for apical Cl-HCO3 exchange as manifested by Cl-dependent extrusion of an intracellular alkali load. Compared with the mature segment, the neonatal mid-CCD exhibited fewer intercalated cells, which were characterized by a less alkaline cell pH, reduced apical Cl-HCO3 exchange activity, and shorter apical binding profiles for PNA. There was evidence for basolateral Cl conductance and similar buffering capacity at all ages. In the neonatal outer cortex there was little or no binding to PNA or to B63. As soon as cell surface antigens characteristic of the fully differentiated beta-cell were detected, functional studies indicated the presence, albeit reduced, of apical Cl-HCO3 exchange. Thus there is postnatal proliferation and maturation of HCO3-secreting intercalated cells in the rabbit kidney; the origin of these cells remains to be determined.

In this paper, we report techniques for mimicking and evaluating the human motion in real time by a therapeutic humanoid robot to improve the imitation skill of children with autism. For realizing the mimicking technique, we propose a method of selecting key frames using a QLearning approach to remove the significant noises. Then, in order to evaluate human motion in real time, we introduce a method of cluster-based framework of Mixture Gaussian and an Expectation-Maximization algorithm using parameters which are converted by Principal Component Analysis. Practical experiments have been performed to test the interaction of children with autism with the robot and evaluate the possibility of improving their imitation skills by training them to perform specific tasks through a robot.

Nutritional interdependence among three representatives of rumen bacteria, Bacteroides amylophilus, Megasphaera elsdenii, and Ruminococcus albus, was studied with a basal medium consisting of minerals, vitamins, cysteine hydrochloride, and NH4'. B. amylophilus grew well in the basal medium supplemented with starch and produced branched-chain amino acids after growth ceased. When cocultured with B. amylophilus in the basal medium supplemented with starch and glucose, amino acid-dependent M. elsdenii produced an appreciable amount of branched-chain fatty acids, which are essential growth factors for cellulolytic R. albus. A small addition of starch (0.1 to 0.3%) to the basal medium containing glucose and cellobiose brought about successive growth of the three species in the order of B. amylophilus, M. elsdenii, and R. albus, and successive growth was substantiated by the formation of branched-chain amino acids and fatty acids in the culture. Supplementation with 0.5% starch, however, failed to support the growth of R. albus. On the basis of these results, the effects of supplementary starch or branched-chain fatty acids on cellulose digestion in the rumen was discussed.

Carbonic anhydrase (CA) IV activity facilitates renal acidification by catalyzing the dehydration of luminal carbonic acid. CA IV has been localized to the proximal tubules and medullary collecting ducts. Maturation of CA IV expression has been considered to be important in the development of renal acid excretion. The purpose of the present study was to determine the maturational expression of CA IV in rabbit kidney. A guinea pig polyclonal antibody to purified rabbit lung microsomal membrane CA IV was generated. Immunoblotting of membrane proteins after peptide- N-glycosidase F treatment revealed two N-glycosylation sites and reduction in size from ∼52 to 35 kDa; there appeared to be heavier glycosylation in the medulla. In membrane and total proteins from the kidney cortex, CA IV was 15–30% of the adult level during the first 2 wk of life but increased to mature levels by 5 wk of age. The maturational pattern in the cortex was confirmed by measuring SDS-resistant CA hydratase activity. In the medulla, both membrane and total proteins were generally less than one-fourth of the adult level of CA IV during the first 2 wk of life before reaching mature levels by 5 wk of age. Immunohistochemistry showed staining in proximal tubules (apical > basolateral), with maximal label in the S2 segment. CA IV also appeared on the apical membranes of a minority cell type of the cortical collecting duct, presumably the α-intercalated cell. Several labeled cells also appeared to be the process of being extruded from medullary collecting ducts of 1- to 2-wk rabbits. The antibody did not reliably detect medullary CA IV expression in sections from mature rabbits. These studies indicate that there is a substantial postnatal increase in expression of CA IV in the maturing kidney in both the cortex and medulla. The disappearance of intercalated cells in the maturing rabbit medullary collecting duct may be part of a normal renal developmental program as previously reported [J. Kim, J.-H. Cha, C. C. Tisher, and K. M. Madsen. Am. J. Physiol. 270 ( Renal Fluid Electrolyte Physiol. 39): F575–F592, 1996]. It is likely that the maturation of CA IV expression contributes to the increase in renal acidification observed early in postnatal life.