A Dynamic Resource Manager with Effective Resource Isolation Based on Workload Types in Virtualized Cloud Computing Environments

To use computing resources for processing parallel algorithms on demand, cloud computing has been widely used since it is able to scale in response to load increases and decreases. Typically, cloud computing providers offer virtual machines to cloud users with static configurations, and these configurations are not changed until virtual machines are shutting down. To accelerate parallel processing computations in cloud computing environments, we design and implement a dynamic resource manager by isolating resources based on workload types. To avoid unnecessary context switching and increase CPUs affinity, our dynamic resource manager determines whether vCPU to physical CPU core pinning is required. If so, the VM’s vCPUs are pinned by our dynamic resource manager, which can guarantee the resource and performance isolation. With our proposed resource manager for virtual machines, we can achieve a performance boost and load balancing at the same time. Performance results show that our proposed method outperforms the default scheduler of Xen about 36.2% by reducing the number of context switching for VMs

Meteorological characteristics and assessment of the effect of local emissions during high PM10 concentration in the Seoul Metropolitan Area

In this study, we investigate the meteorological characteristics and the effect of local emissions during high PM10 concentrations in the Seoul Metropolitan Area (SMA) by utilizing data from a high-resolution urban meteorological observation system network (UMS-Seoul) and The Air Pollution Model (TAPM). For a detailed analysis, days with PM10 concentrations higher than 80 ??g m-3 for daily average PM10 concentration (classified as unhealthy by the Korean Ministry of Environment) in the Seoul Metropolitan Area (SMA) were classified into 3 Cases. Case I was defined as when the prevailing effect was from outside the SMA. Case II was defined as when the prevailing effect was a local effect with outside. Case III was defined as when the prevailing effect was local. Overall, high PM10 concentrations in the SMA mostly occurred under weak migratory anticyclone systems over the Korean Peninsula during warm temperatures. Prior to the PM10 concentration reaching the peak concentration, the pattern in each case was distinctive. After peak concentrations, however, the pattern for the 3 cases became less distinct. This study showed that nearly 50% of the high PM10 concentrations in the SMA occurred in spring and were governed by the conditions for Case II more than these for Cases I and III. In spring, the main sources of the high PM10 concentrations in the SMA were local emissions due to the predominance of weak winds and local circulation. The simulation showed that the non-SMA emissions were about 63 to 73% contribution to the spring high PM10 concentrations in the SMA. Specifically, local point sources including industrial combustion, electric utility, incineration and cement production facilities scattered around the SMA and could account for PM10 concentrations more than 10 ??g m-3 in the SMA

Effect of shared decision-making education on physicians’ perceptions and practices of end-of-life care in Korea

Background Evidence of the ethical appropriateness and clinical benefits of shared decision-making (SDM) are accumulating. This study aimed to not only identify physicians’ perspectives on SDM, and practices related to end-of-life care in particular, but also to gauge the effect of SDM education on physicians in Korea. Methods A 14-item questionnaire survey using a modified Delphi process was delivered to nephrologists and internal medicine trainees at 17 university hospitals. Results A total of 309 physicians completed the survey. Although respondents reported that 69.9% of their practical decisions were made using SDM, 59.9% reported that it is not being applied appropriately. Only 12.3% of respondents had received education on SDM as part of their training. The main obstacles to appropriate SDM were identified as lack of time (46.0%), educational materials and tools (29.4%), and education on SDM (24.3%). Although only a few respondents had received training on SDM, the proportion of those who thought they were using SDM appropriately in actual practice was high; the proportion of those who chose lack of time and education as factors that hindered the proper application of SDM was low. Conclusion The majority of respondents believed that SDM was not being implemented properly in Korea, despite its use in actual practice. To improve the effectiveness of SDM in the Korean medical system, appropriate training programs and supplemental policies that guarantee sufficient application time are required

Life-Threatening Late Hemorrhage due to Superior Thyroid Artery Dissection After Anterior Cervical Discectomy and Fusion

Study Design. Case report. Objective. The object of this report is to identify causes of late bleeding after anterior cervical discectomy and to suggest an optimal management plan. Summary of Background Data. The anterior discectomy and fusion is one of the most common spine procedures for cervical disc disease. Although this procedure has a low postoperative morbidity rate, rarely fatal vascular complications occur, the majority of which can be predicted intraoperatively. However, causes of unpredicted delayed bleeding are not fully understood. Methods. We reviewed the hospital charts and radiographs of a patient who underwent coil embolization for late bleeding after anterior cervical discectomy with fusion (ACDF). Results. A 33-year-old man underwent ACDF for cervical discs at C3-C4 and C4-C5. Intraoperatively, there was no major bleeding and the operation was completed after meticulous hemostasis. The patient was discharged 6 days after surgery without complications. However, at 16 days after surgery, the patient revisited the emergency room with sudden progressive neck swelling and accompanying respiratory difficulty. Because the neck swelling was rapidly progressing, the wound was opened in the intensive care unit under local anesthesia due to suspicion of hematoma. After evacuating the hematoma, we encountered active bleeding, which was controlled with gauze packing, but we were unable to identify the bleeding focus. After intubation, emergency right common carotid angiography was performed. Dissection of the right superior thyroid artery with active bleeding was identified, and this was promptly embolized with coils. After angiographic intervention, the remnant hematoma was removed in an operating room. The patient was discharged 5 days later without complication. Conclusion. This is the first report that shows late hemorrhage due to superior thyroid artery dissection after ACDF. This case cautions that intraoperative injury to an artery, unrecognized at operation, may cause late hemorrhage.Lied B, 2008, ACTA NEUROCHIR, V150, P111, DOI 10.1007/s00701-007-1472-yMenon RK, 2008, ANN NY ACAD SCI, V1142, P200, DOI 10.1196/annals.1444.015Fountas KN, 2007, SPINE, V32, P2310Wang MC, 2007, SPINE, V32, P342Choi JW, 2006, SPINE, V31, pE891Karim A, 2006, NEUROSURGERY, V59, P705, DOI 10.1227/01.NEU.0000229056.02698.6EWong TC, 2005, ORTHOPEDICS, V28, P793Alzamora MG, 2005, NEURORADIOLOGY, V47, P282, DOI 10.1007/s00234-005-1343-2WATTERS WC, 1994, SPINE, V19, P2343JENIS LG, 1994, SPINE, V19, P1291

Protective effects of ginsenoside Rg2 and astaxanthin mixture against UVB-induced DNA damage

Ultraviolet B (UVB) radiation induces skin damage, skin matrix degradation, and wrinkle formation through photochemical reaction and oxidative stress. Therefore, protecting the skin from UVB can prevent skin aging. In this study, we investigated the effects of a mixture (RA) of Rg2, a ginsenoside, and astaxanthin, an antioxidant, on the responses of HaCaT cells exposed to UVB (700 J/m2). The cells were incubated for 24 h after UVB exposure and cell viability was determined by MTT assay. UVB decreased cell viability by 60% compared to that of untreated control cells, whereas RA increased cell viability in a concentration-dependent manner, and this increase was significantly higher than that in the single treatment groups. Further, UVB increased the levels of DNA lesions such as cyclobutane pyrimidine dimer (CPD) and 8-hydroxyguanine (8-OHdG). Conversely, RA decreased both CPD and 8-OHdG levels in a concentration-dependent manner. UVB exposure also increased phosphorylation of ataxia-telangiectasia mutated (ATM) protein kinase and p53 and subsequently increased the levels of GADD45α, p21, and matrix metalloproteinases (MMPs)-3, -9, and -13. Additionally, UVB exposure decreased the level of COL1A1. However, RA treatment decreased the levels of p-ATM, p-p53, GADD45α, p21, MMP-3, -9, and -13 and increased the level of COL1A1 in a concentration-dependent manner. These results suggest that RA reduces UVB-induced cytotoxicity and genotoxicity through up-regulation of DNA repair via the combined effects of Rg2 and astaxanthin

Graded Layer Modification for High Efficiency Hydrogenated Amorphous Silicon-Germanium Solar Cells

Hydrogenated amorphous silicon-germanium (a-SiGe:H) solar cells are fabricated with different thicknesses of the i/n graded layer and profiling shapes for appropriate band gap profiling. Comparison of the solar parameters between the U-shape profiling and the exponential shape (E-shape) profiling has been carried out at the same total thickness. In the U-shape profiling, as the thickness of the i/n graded layer increase, the fill factor (FF) and open circuit voltage (V oc) of p-i-n single-junction a-SiGe:H solar cells increase, but the short circuit current (J sc) of cells decreases. In the E-shape profiling, the J sc of the a-SiGe:H cell is enhanced without significant losses in V oc. For further analysis, a modified E-shape profiling is incorporated in a-Si:H/a-SiGe:H double-junction cells, which has resulted in the improvement of V oc and FF of doublejunction cells to 1.67 V and 0.753, respectively, without significant reduction in J sc,SiGe QE, 12.58 mA/cm 2. © 2012 The Japan Society of Applied Physics.

The Arabidopsis Dynamin-Like Proteins ADL1C and ADL1E Play a Critical Role in Mitochondrial Morphogenesis

Dynamin-related proteins are high molecular weight GTP binding proteins and have been implicated in various biological processes. Here, we report the functional characterization of two dynamin homologs in Arabidopsis, Arabidopsis dynamin-like 1C (ADL1C) and Arabidopsis dynamin-like 1E (ADL1E). ADL1C and ADL1E show a high degree of amino acid sequence similarity with members of the dynamin family. However, both proteins lack the C-terminal Pro-rich domain and the pleckstrin homology domain. Expression of the dominant-negative mutant ADL1C[K48E] in protoplasts obtained from leaf cells caused abnormal mitochondrial elongation. Also, a T-DNA insertion mutation at the ADL1E gene caused abnormal mitochondrial elongation that was rescued by the transient expression of ADL1C and ADL1E in protoplasts. In immunohistochemistry and in vivo targeting experiments in Arabidopsis protoplasts, ADL1C and ADL1E appeared as numerous speckles and the two proteins colocalized. These speckles were partially colocalized with F1-ATPase-γ:RFP, a mitochondrial marker, and ADL2b localized at the tip of mitochondria. These results suggest that ADL1C and ADL1E may play a critical role in mitochondrial fission in plant cells