Reduced contribution of the ipsilateral primary motor cortex to force modulation with short-term motor learning in humans: An NIRS study

How is muscle force modulated during hand exercise? Oxygenation in the contralateral primary motor cortex (M1) has been observed to vary considerably across trials of repetitive handgrip exercise. No linear relationship was observed between the average value of oxygenation determined by a block design study and the force of the handgrip. We found reduced oxygenation in the ipsilateral M1 and unchanged oxygenation in the contralateral M1 during repetitive static handgrip exercises (40% and 60% maximal voluntary contraction; 10 s exercise/75 s rest; 5 sets), which might be due to short-term motor learning. These results support the hypothesis that the ipsilateral M1 might functionally compensate for the contralateral M1 in force modulation during unilateral exercises

Characterization of Alloantigen Specific Human Suppressor T Cells Generated in Mixed Leukocyte Culture (MLC)

The mixed leukocyte culture (MLC) extended to 11 days provides the best source of allospecific suppressor T cell (Ts) as these cultures no longer autostimulate fresh autologous responder cells and have little cytotoxic activity. The suppressor assay is performed by adding these culture primed Ts to flat-bottom microwell cultures of fresh autologous lymphocytes responding to the same stimulator cells used for Ts induction. These Ts are radioresistant similar to the naturally occurring human Ts of the MLC. The phenotype of the Ts generated in this model is CD2+, CD8+ and 9.3+. No suppressor activity is found in the lymphocyte subset bearing the CD4 antigen. Studies on the antigen specificity of these alloactivated Ts povide formal evidence that not only Class II but also Class I HLA antigens can suffice as the target antigen(s). Preliminary data is provided to suggest that there are HLA antigens to which a given individual will easily make Ts and HLA antigens to which that individual will not readily produce Ts. It is suggested that this may be due to the genetic background of the responder and thus may be under Ir gene control as in the mouse. The antigen specificity of these Ts has been demonstrated by their failure to suppress the response of autologous lymphocytes to stimulator cells bearing unrelated alloantigens present in the same cultures. However, suppression of the response to unrelated alloantigens can be produced by presentation of those antigen(s) on the same cell bearing the suppressor inducer target antigen

Nature of cultured cells of the skin from acatalasemic individuals with Takahara's disease

For the purpose to clarify whether minimal catalatic activity exists in Japanese acatalasemic cells or not and the manner how extrinsic hydrogen peroxide affects the acatalasemic cells, the author performed tissue cultures using the skin specimens from four acatalasemic persons affected with Takahara's disease and studied the nature of these cultured cells. The results are summarized as follows. 1. Between normal and acatalasemic cultured cells, no morphological differences could be seen and the growth rate of these cell-lines was similar to one another. 2. On the activity of succinoxidase and cytochrome oxidase there could be observed no difference between normal and acatalasemic cells. 3. In each acatalasemic cell line the minimal catalatic activity was observed and it seemed that this activity has an important role in decomposing hydrogen peroxide under normal metabolic pathway. 4. After treating with 10-4M hydrogen peroxide, respiratory enzyme activities and the growth rate in the acatalasemic cells were markedly disturbed, while in normal cells these remained almost intact. 5. There could be observed no differences between normal and acatalasemic cultured cells after X-ray irradiation (200 to 600 r) on the succinoxidase activity, catalatic activity and growth rate.</p

Weak Resilience of Networked Control Systems

In this paper, we propose a method to establish a networked control system that maintains its stability in the presence of certain undesirable incidents on local controllers. We call such networked control systems weakly resilient. We first derive a necessary and sufficient condition for the weak resilience of networked systems. Networked systems do not generally satisfy this condition. Therefore, we provide a method for designing a compensator which ensures the weak resilience of the compensated system. Finally, we illustrate the efficiency of the proposed method by a power system example based on the IEEE 14-bus test system

Nonlinear analyses of folded-plate structure using meshfree method

広島大学(Hiroshima University)博士(工学)Engineeringdoctora

Learning-Dependent Gene Expression of CREB1 Isoforms in the Molluscan Brain

Cyclic AMP-responsive element binding protein1 (CREB1) has multiple functions in gene regulation. Various studies have reported that CREB1-dependent gene induction is necessary for memory formation and long-lasting behavioral changes in both vertebrates and invertebrates. In the present study, we characterized Lymnaea CREB1 (LymCREB1) mRNA isoforms of spliced variants in the central nervous system (CNS) of the pond snail Lymnaea stagnalis. Among these spliced variants, the three isoforms that code a whole LymCREB1 protein are considered to be the activators for gene regulation. The other four isoforms, which code truncated LymCREB1 proteins with no kinase inducible domain, are the repressors. For a better understanding of the possible roles of different LymCREB1 isoforms, the expression level of these isoform mRNAs was investigated by a real-time quantitative RT-PCR method. Further, we examined the changes in gene expression for all the isoforms in the CNS after conditioned taste aversion (CTA) learning or backward conditioning as a control. The results showed that CTA learning increased LymCREB1 gene expression, but it did not change the activator/repressor ratio. Our findings showed that the repressor isoforms, as well as the activator ones, are expressed in large amounts in the CNS, and the gene expression of CREB1 isoforms appeared to be specific for the given stimulus. This was the first quantitative analysis of the expression patterns of CREB1 isoforms at the mRNA level and their association with learning behavior

Parameter Estimation of Hybrid Sinusoidal FM-Polynomial Phase Signal

This paper considers parameter estimation of a hybrid sinusoidal frequency modulated (FM) and polynomial phase signal (PPS) from a finite number of samples. We first show limitations of an existing method, the high-order ambiguity function (HAF), and then propose a new method by adopting the high-order phase function which was originally designed for the pure PPS. The proposed method estimates parameters of interest from peak locations in the time-frequency rate domain, which are less perturbed by the noise than peak values used by the HAF-based method. Numerical evaluation shows the proposed method can handle the hybrid FM-PPS signal with low sinusoidal frequency and improve estimation accuracy in terms of mean squared error for several orders of magnitude

Direct Observation of Dimerization between Different CREB1 Isoforms in a Living Cell

Cyclic AMP-responsive element binding protein 1 (CREB1) plays multiple functions as a transcription factor in gene regulation. CREB1 proteins are also known to be expressed in several spliced isoforms that act as transcriptional activators or repressors. The activator isoforms, possessing the functional domains for kinase induction and for interaction with other transcriptional regulators, act as transcriptional activators. On the other hand, some isoforms, lacking those functional domains, are reported to be repressors that make heterodimers with activator isoforms. The complex and ingenious function for CREB1 arises in part from the variation in their spliced isoforms, which allows them to interact with each other. To date, however, the dimerization between the activator and repressor isoforms has not yet been proved directly in living cells. In this study, we applied fluorescence cross-correlation spectroscopy (FCCS) to demonstrate direct observation of dimerization between CREB1 activator and repressor. The FCCS is a well established spectroscopic method to determine the interaction between the different fluorescent molecules in the aqueous condition. Using differently labeled CREB1 isoforms, we successfully observed the interaction of CREB1 activator and repressor via dimerization in the nuclei of cultured cells. As a result, we confirmed the formation of heterodimer between CREB1 activator and repressor isoforms in living cells