1,431 research outputs found
An economic cost model for network deployment and spectrum in wireless networks
We describe the basic economic theory of cost model for network deployment and spectrum in wireless networks. In particular, we develop a production function for wireless networks. With this production function model, we explore the technical rate of substitution and the elasticity of substitution in the production function for wireless network and find its insight for wireless network. Finally, we compare the engineering value of spectrum and economic value of spectrum
Design and Implementation of Security OS: A Case Study
The importance of a security operating system (OS) with security-enhancing mechanisms at the kernel level, such as a reference monitor and a cryptographic file system, has been increasingly emphasized as the weaknesses and limitation of mechanisms at the user level have been revealed. However, when a system has only a reference monitor, the system is vulnerable to a low-level detour or a physical attack. In addition, when a system has only a cryptographic file system, the file system has a difficulty in protecting itself. To address these problems, we designed and developed a security OS with a reference monitor, a cryptographic file system, authentication limitation, and session limitation. Here we describe the model, its implementation, and its overheads
Soft X-ray resonant Kerr rotation measurement and simulation of element-resolved and interface-sensitive magnetization reversals in a NiFe/FeMn/Co trilayer structure
We report experimental observations of element- and buried interface-resolved magnetization reversals in an oppositely exchange-biased NiFeFeMnCo trilayer structure by soft x-ray resonant Kerr rotation measurements. Not only Co-, Ni-, Fe-specific exchange-biased loops but also interfacial uncompensated (UC) Fe reversal loops coupled to the individual Co and NiFe layers are separately observed. From the experimental results interpreted with the help of the model simulations of soft x-ray resonant Kerr rotation, the effective thicknesses of interfacial UC regions at the buried interfaces of both FeMnCo and NiFeFeMn are found to be tUC =13??2 A and 6??4 A, respectively. The depth sensitivity as well as element specificity of the x-ray resonant Kerr effect offer an elegant way into the investigations of element- and depth-resolved magnetization reversals of ferromagnetic ultrathin regions at buried interfaces in multicomponent multilayer films.open91
Toward a Standardized Strategy of Clinical Metabolomics for the Advancement of Precision Medicine
Despite the tremendous success, pitfalls have been observed in every step of a clinical metabolomics workflow, which impedes the internal validity of the study. Furthermore, the demand for logistics, instrumentations, and computational resources for metabolic phenotyping studies has far exceeded our expectations. In this conceptual review, we will cover inclusive barriers of a metabolomics-based clinical study and suggest potential solutions in the hope of enhancing study robustness, usability, and transferability. The importance of quality assurance and quality control procedures is discussed, followed by a practical rule containing five phases, including two additional "pre-pre-" and "post-post-" analytical steps. Besides, we will elucidate the potential involvement of machine learning and demonstrate that the need for automated data mining algorithms to improve the quality of future research is undeniable. Consequently, we propose a comprehensive metabolomics framework, along with an appropriate checklist refined from current guidelines and our previously published assessment, in the attempt to accurately translate achievements in metabolomics into clinical and epidemiological research. Furthermore, the integration of multifaceted multi-omics approaches with metabolomics as the pillar member is in urgent need. When combining with other social or nutritional factors, we can gather complete omics profiles for a particular disease. Our discussion reflects the current obstacles and potential solutions toward the progressing trend of utilizing metabolomics in clinical research to create the next-generation healthcare system.11Ysciescopu
Role of G{alpha}12 and G{alpha}13 as Novel Switches for the Activity of Nrf2, a Key Antioxidative Transcription Factor
G{alpha}12 and G{alpha}13 function as molecular regulators responding to extracellular stimuli. NF-E2-related factor 2 (Nrf2) is involved in a protective adaptive response to oxidative stress. This study investigated the regulation of Nrf2 by G{alpha}12 and G{alpha}13. A deficiency of G{alpha}12, but not of G{alpha}13, enhanced Nrf2 activity and target gene transactivation in embryo fibroblasts. In mice, G{alpha}12 knockout activated Nrf2 and thereby facilitated heme catabolism to bilirubin and its glucuronosyl conjugations. An oligonucleotide microarray demonstrated the transactivation of Nrf2 target genes by G{alpha}12 gene knockout. G{alpha}12 deficiency reduced Jun N-terminal protein kinase (JNK)-dependent Nrf2 ubiquitination required for proteasomal degradation, and so did G{alpha}13 deficiency. The absence of G{alpha}12, but not of G{alpha}13, increased protein kinase C {delta} (PKC {delta}) activation and the PKC {delta}-mediated serine phosphorylation of Nrf2. G{alpha}13 gene knockout or knockdown abrogated the Nrf2 phosphorylation induced by G{alpha}12 deficiency, suggesting that relief from G{alpha}12 repression leads to the G{alpha}13-mediated activation of Nrf2. Constitutive activation of G{alpha}13 promoted Nrf2 activity and target gene induction via Rho-mediated PKC {delta} activation, corroborating positive regulation by G{alpha}13. In summary, G{alpha}12 and G{alpha}13 transmit a JNK-dependent signal for Nrf2 ubiquitination, whereas G{alpha}13 regulates Rho-PKC {delta}-mediated Nrf2 phosphorylation, which is negatively balanced by G{alpha}12
Growth characteristics and productivity of cold-tolerant “Kowinearly” Italian ryegrass in the northern part of South Korea
The objective of this research is to evaluate differences in growth characteristics and productivity between Kowinearly and Florida 80 Italian ryegrass varieties in regions with severely cold winters. This research was carried out in Suwon (in central South Korea) and Yonchun (in northern South Korea) during the 2002 2006 growing seasons. Kowinearly is a diploid variety with green leaf colour and a semi prostrate growth habit in autumn and a semi-erect one in spring. There were differences among the varieties in terms of cold tolerance, heading date, and forage yield in Yonchun. The winter field survival of Kowinearly was 85%, while that of Florida 80 was 43%. The dry matter yield of Kowinearly in Yonchun was 9,662 kg/ha, which was 31% more than that of Florida 80. In Suwon, the heading date of Kowinearly was May 7, which was 2 days later than that of Florida 80. In Yonchun, Kowinearly’s heading date was May 12, 1 day earlier than that of Florida 80. These results indicate that Kowinearly has good cold tolerance, and that in spring, it starts growth earlier than Florida 80, because of its higher cold tolerance.Keywords: Italian ryegrass, Kowinearly, cold tolerance, new variety, forage cro
Acute Spontaneous Subdural Hematoma of Arterial Origin
Acute spontaneous subdural hematoma (SDH) of arterial origin is very rare. We report a case of acute spontaneous SDH that showed contrast media extravasation from cortical artery on angiograms. A 58-year-old male patient developed sudden onset headache and right hemiparesis. Brain CT scan demonstrated acute SDH at left convexity. The patient was drowsy mentality on admission. He had no history of head trauma. Cerebral angiography was performed and revealed a localized extravasation of the contrast media from distal cortical MCA branch. After angiography, the patient deteriorated to comatose mentality. Decompressive craniectomy for removal of SDH was performed. We verified the arterial origin of the bleeding and coagulated the bleeding focus. The histological diagnosis was aneurysmal artery. He recovered after surgery with mild disability. In a case of acute spontaneous SDH, the possibility of a cortical artery origin should be considered
Distribution of particulate organic matter in the Kum River, Korea
Article信州大学理学部附属諏訪臨湖実験所報告 9: 101-110(1995)departmental bulletin pape
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