Autophagy (or self eating), a cellular recycling mechanism, became the center of interest and subject of intensive research in recent years. Development of new molecular techniques allowed the study of this biological...
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There is a growing body of experimental evidence suggesting that the Ca2+ signaling in ventricular myocytes is characterized by a high gradient near the cell membrane and a more uniform Ca2+ distribution in the cell i...
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There is a growing body of experimental evidence suggesting that the Ca2+ signaling in ventricular myocytes is characterized by a high gradient near the cell membrane and a more uniform Ca2+ distribution in the cell interior [1]--[7]. An important reason for this phenomenon might be that in these cells the t-tubular system forms a network of extracellular space, extending deep into the cell interior. This allows the electrical signal, that propagates rapidly along the cell membrane, to reach the vicinity of the sarcoplasmic reticulum (SR), where intracellular Ca2+ required for myofilament activation is stored [1], [8]--[11]. Early studies of cardiac muscle showed that the t-tubules are found at intervals of about 2 lm along the longitudinal cell axis in close proximity to the Z-disks of the sarcomeres [12]. Subsequent studies have demonstrated that the t-tubular system has also longitudinal extensions [9]--[11], [13].
Brachypodium distachyon (L.) Beauv. is a temperate wild grass species;its morphological and genomic characteristics make it a model system when compared to many other grass species. It has a small genome, short growth...
Brachypodium distachyon (L.) Beauv. is a temperate wild grass species;its morphological and genomic characteristics make it a model system when compared to many other grass species. It has a small genome, short growth cycle, self-fertility, many diploid accessions, and simple growth requirements. In addition, it is phylogenetically close to economically important crops, like wheat and barley, and several potential biofuel grasses. It exhibits agricultural traits similar to those of these target crops. For cereal genomes, it is a better model than Arabidopsis thaliana and Oryza sativa (rice), the former used as a model for all flowering plants and the latter hitherto used as model for genomes of all temperate grass species including major cereals like barley and wheat. Increasing interest in this species has resulted in the development of a series of genomics resources, including nuclear sequences and BAC/EST libraries, together with the collection and characterization of other genetic resources. It is expected that the use of this model will allow rapid advances in generation of genomics information for the improvement of all temperate crops, particularly the cereals.
Time resolved imaging and fluorescent assays were used to examine the biological response of confluent cell cultures to pulsed laser microbeam cell lysis using cavitation bubbles generated by Nd:YAG nanosecond laser p...
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Comparative sequence analysis is a powerful approach to identify functional elements for functional genomics. For gene prediction, this would mean whether given genomic sequences exhibit significant similarity to some...
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ISBN:
(纸本)9781932415834
Comparative sequence analysis is a powerful approach to identify functional elements for functional genomics. For gene prediction, this would mean whether given genomic sequences exhibit significant similarity to some arbitrary region in the genome sequence of an evolutionary related organism or not. Three gene prediction methods were examined to see how they perform on randomly chosen sequences. The focus was on examining the methods rather than data analysis. Thus, the dataset was selected in a flexible manner and may be biased. Our analysis of methods indicated that there are not many differences between recent version of *** and GENSCAN in terms of the algorithm used. Both programs use duration HMM and can predict genes and exons on both DNA strands simultaneously. MZEF, on the other hand, uses completely different approach. It employs quadratic discriminant function to distinguish between coding and noncoding regions. The analysis showed that the new generation of programs has substantially better results than the programs analyzed in previous studies. Specifically, *** and GENSCAN performed relatively better than MZEF.
Astronaut biomechanical performance depends on a wide variety of factors. Results from computational modeling suggest that muscle function - a key component of performance - could be modulated by compliance of the con...
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Astronaut biomechanical performance depends on a wide variety of factors. Results from computational modeling suggest that muscle function - a key component of performance - could be modulated by compliance of the contractile filaments in muscle, especially when force is low such as transient Ca 2+ activation in a twitch, reduced activation in muscle fatigue encountered during EVA, or perhaps atrophy during prolonged space flight. We used Monte-Carlo models to investigate the hypotheses that myofilament compliance influences muscle function during a twitch, and also modulates the effects of cooperative interactions between contractile proteins on force generation. Peak twitch force and the kinetics of force decay were both decreased, while tension cost was increased, when myofilament compliance was increased relative to physiological values. Both the apparent Ca 2+-sensitivity and cooperativity of activation of steady-state isometric force were altered by myofilament compliance even when there were no explicit interactions included between binding sites. The effects of cooperative interactions between adjacent regulatory units were found to be greater than either the effect of myofilament compliance on apparent cooperativity of activation or that due to myosin cross-bridge induced cooperativity. These results indicate that muscle function may be "tuned" at the molecular level, particularly under conditions of reduced Ca2+-activation.
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