• Journal of KIISE:Computer Systems and Theory
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• v.34 no.2
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• pp.49-56
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• 2007

MEMS-based storage is being developed as a new storage media. Due to its attractive features such as high-bandwidth, low-power consumption, high-density, and low cost, MEMS storage is anticipated to be used for a wide range of applications from storage for small handhold devices to high capacity mass storage servers. However, MEMS storage has vastly different physical characteristics compared to a traditional disk. First, MEMS storage has thousands of heads that can be activated simultaneously. Second, the media of MEMS storage is a square structure which is different from the platter structure of disks. This paper presents a new request scheduling algorithm for MEMS storage that makes use of the aforementioned characteristics. This new algorithm considers the parallelism of MEMS storage as well as the seek time of requests on the two dimensional square structure. We then extend this algorithm to consider the aging factor so that starvation resistance is improved. Simulation studies show that the proposed algorithms improve the performance of MEMS storage by up to 39.2% in terms of the average response time and 62.4% in terms of starvation resistance compared to the widely acknowledged SPTF (Shortest Positioning Time First) algorithm.

• The Korean Journal of Physiology and Pharmacology
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• v.13 no.6
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• pp.491-496
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• 2009

Skeletal muscle atrophy is a common phenomenon during the prolonged muscle disuse caused by cast immobilization, extended aging states, bed rest, space flight, or other factors. However, the cellular mechanisms of the atrophic process are poorly understood. In this study, we investigated the involvement of mitogen-activated protein kinase (MAPK) in the expression of muscle-specific RING finger 1 (MuRF1) during atrophy of the rat gastrocnemius muscle. Histological analysis revealed that cast immobilization induced the atrophy of the gastrocnemius muscle, with diminution of muscle weight and cross-sectional area after 14 days. Cast immobilization significantly elevated the expression of MuRF1 and the phosphorylation of p38 MAPK. The starvation of L6 rat skeletal myoblasts under serum-free conditions induced the phosphorylation of p38 MAPK and the characteristics typical of cast-immobilized gastrocnemius muscle. The expression of MuRF1 was also elevated in serum-starved L6 myoblasts, but was significantly attenuated by SB203580, an inhibitor of p38 MAPK. Changes in the sizes of L6 myoblasts in response to starvation were also reversed by their transfection with MuRF1 small interfering RNA or treatment with SB203580. From these results, we suggest that the expression of MuRF1 in cast-immobilized atrophy is regulated by p38 MAPK in rat gastrocnemius muscles.

• Journal of Microbiology and Biotechnology
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• v.26 no.12
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• pp.2106-2115
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• 2016

To identify the global effects of (p)ppGpp in the gram-positive bacterium Deinococcus radiodurans, which exhibits remarkable resistance to radiation and other stresses, RelA/SpoT homolog (RSHs) mutants were constructed by direct deletion mutagenesis. The results showed that RelA has both synthesis and hydrolysis domains of (p)ppGpp, whereas RelQ only synthesizes (p)ppGpp in D. radiodurans. The growth assay for mutants and complementation analysis revealed that deletion of relA and relQ sensitized the cells to $H_2O_2$, heat shock, and amino acid limitation. Comparative proteomic analysis revealed that the bifunctional RelA is involved in DNA repair, molecular chaperone functions, transcription, the tricarboxylic acid cycle, and metabolism, suggesting that relA maintains the cellular (p)ppGpp levels and plays a crucial role in oxidative resistance in D. radiodurans. The D. radiodurans relA and relQ genes are responsible for (p)ppGpp synthesis/hydrolysis and (p)ppGpp hydrolysis, respectively. (p)ppGpp integrates a general stress response with a targeted re-programming of gene regulation to allow bacteria to respond appropriately towards heat shock, oxidative stress, and starvation. This is the first identification of RelA and RelQ involvement in response to oxidative, heat shock, and starvation stresses in D. radiodurans, which further elucidates the remarkable resistance of this bacterium to stresses.

• Applied Microscopy
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• v.26 no.1
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• pp.59-65
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• 1996

The silkworm feeding behaviour reveals two types of feeding response i. e., energetic and inert feeding response to diet. These two new technical terms are being introduced in the present study. The structures of functional organs of mouthpart and antenna of energetic and inert feeding response to diet were examined by scanning electron microscope. There is a big variations in the ultrastructures of different sensilla. The maxillary palpi or sensilla basiconica at the top of maxillary palpus of maxilla are well developed in the energetic larva while in the inert larva, these organs on the right side are extremely deformed. Similarly, these sensilla on the third segment of antenna are well developed in the larva energetic to diet has only two deformed sensilla basiconica, that is why silkworm can not show a proper form. This is related to abnormality and it is due to the fact that behaviour is too strong to select the food but fails and finally dies of the starvation.

• Korean Journal of Ecology and Environment
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• v.38 no.4 s.114
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• pp.510-517
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• 2005

The filamentous cyanobacterium Anabaena is capable of both photosynthesis and nitrogen fixation which probably facilitated its incredible adaptation and proliferation in freshwater environments. A small gene, patS, was found to block nitrogen fixing cells from developing which resulted in death of Anabaena in the absence of combined nitrogen sources. We analyzed the DNA sequences in the vicinity of the patS gene by using a codon usage program and detected no codon bias other than the patS open reading frame. Three overlapping cosmids that contain the patS gene were identified, and the presence of other known heterocyst-controlling genes was examined. The patS expression in response to nitrogen starvation was analyzed at the level of transcription and translation by using Northern blot analyses and lacZ-reporter-gene fusion experiments, respectively. The patS expression increased rapidly (within 12 hours) upon the removal of combined nitrogen from the media.

• Journal of Microbiology and Biotechnology
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• v.17 no.2
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• pp.305-312
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• 2007

This study focused on the involvement of the unusual nucleotide (p)ppGpp, a stringent factor, during the morphological and physiological differentiation of Streptomyces coelicolor. Two genes, relA and rshA, were disrupted to demonstrate the roles of the stringent factor in the differentiation. The intracellular concentration of (p)ppGpp in the wild-type (M600) and disrupted mutants was measured in relation to the intentional starvation of a specific nutrient, such as carbon, nitrogen, and phosphate or the in situ depletion of nutrients in a batch culture. As a result, it was found that the morphological characteristic of the ${\Delta}relA$ mutant was a bld phenotype forming condensed mycelia, whereas the ${\Delta}rshA$ mutant grew fast-forming spores and straightforward mycelia. In both mutants, the production of actinorhodin (Act) was completely abolished, yet the undecylprodigiosin (Red) production was increased. Intracellular (p)ppGpp was detected in the ${\Delta}relA$ mutant in the case of limited phosphate, yet not with limited carbon or nitrogen sources. In contrast, (p)ppGpp was produced in the ${\Delta}rshA$ mutant under limited carbon and nitrogen conditions. Therefore, (p)ppGpp in S. coelicolor was found to be selectively regulated by either the RelA or RshA protein, which was differentially expressed in response to the specific nutrient limitation. These results were also supported by the in situ ppGpp production during a batch culture. Furthermore, it is suggested that RelA and RshA are bifunctional proteins that possess the ability to both synthesize and hydrolyze (p)ppGpp.

• Food Science and Preservation
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• v.18 no.4
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• pp.612-619
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• 2011

Cronobacter sakazakii has been isolated from a wide range of environmental sources and from several foods of animal and plant origin. The objective of this study was to determine the resistance of C. sakazakii (ATCC 12868, ATCC 29004, and ATCC 29544) in cold, cold-freeze thaw, cold-acid, and cold starvation-freeze thaw stress. The number of C. sakazakii decreased to 1 log CFU/mL at $5^{\circ}C$ (cold storage) for 10 days. When C. sakazakii was cultivated at a low temperature ($13^{\circ}C$), the population of C sakazakii ATCC 12868 and 29004 increased to $10^9$ CFU/mL, and the population of C. sakazakii ATCC 29544 increased to $10^8$ CFU/mL. For C. sakazakii ATCC 12868 and 29004, the cold-adapted cells ($5^{\circ}C$ 24 hr) decreased by 4 log CFU/mL, and the low-temperature-cultivated cells ($13^{\circ}C$) decreased by 0.5 log CFU/mL. In this study, low-temperature cultivation enhanced the freeze-thaw cross-resistance due to the metabolic changes in the cells. Cold stress ($5^{\circ}C$ 48 hr, $13^{\circ}C$ cultivation) enhanced the cold-acid cross-resistance. The cold-starved cells in the sterilized 0.1% peptone water enhanced the freeze-thaw cross-resistance with significant differences (p<0.05). Therefore, the increased tolerance of the cold-adapted or low-temperature-cultivated C. sakazakii cells to freeze-thaw, acid, or starvation suggests that such environments should be considered when processing minimally processed foods or foods with extended shelf life.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.9
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• pp.3663-3679
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• 2020

Scheduling plays a dynamic role in cloud computing in generating as well as in efficient distribution of the resources of each task. The principle goal of scheduling is to limit resource starvation and to guarantee fairness among the parties using the resources. The demand for resources fluctuates dynamically hence the prearranging of resources is a challenging task. Many task-scheduling approaches have been used in the cloud-computing environment. Security in cloud computing environment is one of the core issue in distributed computing. We have designed a deep learning-based security model for scheduling tasks in cloud computing and it has been implemented using CloudSim 3.0 simulator written in Java and verification of the results from different perspectives, such as response time with and without security factors, makespan, cost, CPU utilization, I/O utilization, Memory utilization, and execution time is compared with Round Robin (RR) and Waited Round Robin (WRR) algorithms.

• Korean Journal of Plant Tissue Culture
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• v.27 no.5
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• pp.411-413
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• 2000

The ability of microspores or young pollen grains (male gametophytes) to undergo developmetal switch to embryogenic (sporophytic) pathway exemplifies the concept of totipotency as applied to haploid posmeiotic cells. As a first step pollen is devoid of positional information provided in situ by the intact anther - by isolation and cultivation in vitro in artificial media. This is inevitably accompanied by some degree of stress response in microspore/pollen. It has been shown in both monocots and dicots that intentional stress treatment (mostly starvation or heat shock) greatly stimulates embryo induction rate. Using transgenic sHSP antisense Nicotiana tabacum we show that expression of small heat shock proteins is an integral part of successful embryo and later haploid plant production from pollen grains. Our recently published data show that sHSP chaperone function is optimal in the absence of ATP.

• Molecules and Cells
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• v.20 no.2
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• pp.271-279
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• 2005

Although macrophages are an important first line of cellular defense, they are unable to effectively kill phagocytosed C. albicans. To determine the physiological basis of this inability, we investigated the alterations of macrophage proteins caused by C. albicans infection. Since the formation of C. albicans hyphae caused cell death, proteins were prepared 3 h after infection and examined by two-dimensional gel electrophoresis (2-DE). The most prominent changes were in glycolytic enzymes, which could have caused energy depletion of the infected cells. Also changed were proteins involved in maintenance of cellular integrity and NO production. Treatment of the macrophages with either cytochalasin D or taxol did not alter their inability to kill C. albicans. Our results indicate that multiple factors contribute to cell death as the pathogenic form of C. albicans becomes fully active inside macrophage cells.