Dynamic Voltage and Frequency Scaling Techniques for Chip Multiprocessor Designs

Due to chip power density limitations as well as the recent breakdown of Dennard's Scalingover the past decade, performance growth in microprocessor design has largely been driven by core scaling. These trends have led to Chip Multi- Processor(CMP) designs, currently with tens of cores, and expected to grow to the thousands in the pursuit of exascale computing. The more complicated CMP design is more leading power consumption relatively in computer architecture. The increased power consumption generates thermal issues, and so performance degradation. Therefore, it is certain that power efficient algorithm in CMP and main memory are essential. For the power efficiency, we focus on dynamic voltage/frequency scaling (DVFS) techniques for CMP and main memory. In the first work, we focus on the "uncore", consisting of an on-chip communication fabric and shared LLC in CMP. The uncore now occupies as much as 30% of the overall die area, which is not negligible in CMP design, but has rarely researched. We find there are predictable patterns in uncore utility which point towards the potential of a proactive approach to uncore power management. In this work, we utilize artificial intelligence principles to proactively leverage uncore utility pattern prediction via an Artificial Neural Network (ANN). Even though the uncore takes non-negligible portion of CMP power consumption, processor cores still exist as major power consumers. For core DVFS, We explore a novel approach with the potential to achieve synergistic energy-savings and performance gain in chip multiprocessors (CMPs). In current designs, performance must typically be traded-off to achieve energy savings or, conversely, performance gains come with significant energy overhead. Resources shared by processor cores, such as on-chip interconnect and shared memory, play an increasingly critical role in determining the overall CMP performance. Our key observation is that per-core DVFS can be used as a client regulation mechanism for the shared resources. Based on this observation, we propose a new DVFS technique inspired by TCP Vegas, a congestion control protocol from the IP-networking domain. In addition to uncore in CMP, main memory is also critical shared resource in total system. As uncore is critical resource for CMP performance while occupying critical portion of total CMP energy consumed, main memory is also critical for total performance and accounts for large fraction of total energy consumption. Most conventional approaches focused on utilization of cores and memory only for memory power management. We found, however, the uncore plays an important role of total system performance and its utilization must be considered as well for memory power management. From the observation, we propose shared resource utilization aware power management technique for main memory. Our technique chooses low V/F level of memory for some congested case in uncore, and so derives negligible performance degradation while saving more energy by the low V/F level. We also proposed coordination policies to avoid oscillation issues among individual DVFS techniques (i.e. over energy saving or over performance increment). Full system simulations on PARSEC benchmarks show that our coordinated technique reduces total energy dissipation by over 47% across all benchmarks with less than 2.3% performance degradation

High-resolution crystal structure of the non-specific lipid-transfer protein from maize seedlings

AbstractBackground: The movement of lipids between membranes is aided by lipid-transfer proteins (LTPs). Some LTPs exhibit broad specificity, transferring many classes of lipids, and are termed non-specific LTPs (ns-LTPs). Despite their apparently similar mode of action, no sequence homology exists between mammalian and plant ns-LTPs and no three-dimensional structure has been reported for any plant ns-LTP.Results We have determined the crystal structure of ns-LTP from maize seedlings by multiple isomorphous replacement and refined the structure to 1.9 å resolution. The protein comprises a single compact domain with four α-helices and a long C-terminal region. The eight conserved cysteines form four disulfide bridges (assigned as Cys4–Cys52, Cys14–Cys29, Cys30–Cys75, and Cys50–Cys89) resolving the ambiguity that remained from the chemical determination of pairings in the homologous protein from castor bean. Two of the bonds, Cys4–Cys52 and Cys50–Cys89, differ from what would have been predicted from sequence alignment with soybean hydrophobic protein. The complex between maize ns-LTP and hexadecanoate (palmitate) has also been crystallized and its structure refined to 1.8 å resolution.Conclusion The fold of maize ns-LTP places it in a new category of all-α-type structure, first described for soybean hydrophobic protein. In the absence of a bound ligand, the protein has a tunnel-like hydrophobic cavity, which is large enough to accommodate a long fatty acyl chain. In the structure of the complex with palmitate, most of the acyl chain is buried inside this hydrophobic cavity

Visfatin exerts angiogenic effects on human umbilical vein endothelial cells through the mTOR signaling pathway

AbstractThe biologically active factors known as adipocytokines are secreted primarily by adipose tissues and can act as modulators of angiogenesis. Visfatin, an adipocytokine that has recently been reported to have angiogenic properties, is upregulated in diabetes, cancer, and inflammatory diseases. Because maintenance of an angiogenic balance is critically important in the management of these diseases, understanding the molecular mechanism by which visfatin promotes angiogenesis is very important. In this report, we describe our findings demonstrating that visfatin stimulates the mammalian target of the rapamycin (mTOR) pathway, which plays important roles in angiogenesis. Visfatin induced the expression of hypoxia-inducible factor 1α (HIF1α) and vascular endothelial growth factor (VEGF) in human endothelial cells. Inhibition of the mTOR pathway by rapamycin eliminated the angiogenic and proliferative effects of visfatin. The visfatin-induced increase in VEGF expression was also eliminated by RNA interference-mediated knockdown of the 70-kDa ribosomal protein S6 kinase (p70S6K), a downstream target of mTOR. Visfatin inactivated glycogen synthase kinase 3β (GSK3β) by phosphorylating it at Ser-9, leading to the nuclear translocation of β-catenin. Both rapamycin co-treatment and p70S6K knockdown inhibited visfatin-induced GSK3β phosphorylation at Ser-9 and nuclear translocation of β-catenin. Taken together, these results indicate that mTOR signaling is involved in visfatin-induced angiogenesis, and that this signaling leads to visfatin-induced VEGF expression and nuclear translocation of β-catenin

Image quality and attenuation values of multi detector CT coronary angiography using high iodine-concentration contrast material: A comparison of the use of iopromide 370 and iomeprol 400

Background: Effects of high iodine-concentration contrast material on the image quality of coronary CT angiography (CCTA) have not been well evaluated

Decreased health-related quality of life in disease-free survivors of differentiated thyroid cancer in Korea

<p>Abstract</p> <p>Background</p> <p>Concern regarding the health-related quality of life (HRQOL) of long-term survivors of thyroid cancer has risen due to the rapid increase in the incidence of thyroid cancer, which generally has an excellent prognosis. The aim of this study was to evaluate the status of HRQOL in disease-free survivors of differentiated thyroid carcinoma (DTC) and to evaluate the important determinants of HRQOL.</p> <p>Methods</p> <p>This was a cross-sectional study in which we interviewed consecutive disease-free survivors of DTC. Three different validated questionnaires ("EORTC QLQ-C30" for various functional domains, the "brief fatigue inventory (BFI)" and the "hospital anxiety and depression scale" (HADS)) were used. Data from a large, population based survey of 1,000 people were used as a control.</p> <p>Results</p> <p>The response rate for the questionnaires was 78.9% (316/401). Disease-free survivors of DTC showed a decreased HRQOL in all five functional domains (physical, role, cognitive, emotional, and social) on the EORTC QLQ-C30 compared with controls (<it>P </it>< 0.01). BFI and HADS-anxiety scores also showed greater distress in disease-free survivors of DTC than in controls (<it>P </it>< 0.05). A multiple regression analysis for the determinants of HRQOL showed that the HADS-anxiety, HADS-depression, and BFI scores were the most significant components of decreased HRQOL.</p> <p>Conclusions</p> <p>Although disease-free survivors of DTC are expected to have disease-specific survival comparable to the general population, they experience a significantly decreased HRQOL. Anxiety, depression, and fatigue were the major determinants of the decreased HRQOL. Supportive psychological care should be integrated into the management of long-term survivors of DTC.</p

Predictors of intentional intoxication using decision tree modeling analysis: a retrospective study

Objective The suicide rate in South Korea is very high and is expected to increase in coming years. Intoxication is the most common suicide attempt method as well as one of the common reason for presenting to an emergency medical center. We used decision tree modeling analysis to identify predictors of risk for suicide by intentional intoxication. Methods A single-center, retrospective study was conducted at our hospital using a 4-year registry of the institute from January 1, 2013 to December 31, 2016. Demographic factors, such as sex, age, intentionality, therapeutic adherence, alcohol consumption, smoking status, physical disease, cancer, psychiatric disease, and toxicological factors, such as type of intoxicant and poisoning severity score were collected. Candidate risk factors based on the decision tree were used to select variables for multiple logistic regression analysis. Results In total, 4,023 patients with intoxication were enrolled as study participants, with 2,247 (55.9%) identified as cases of intentional intoxication. Reported annual percentages of intentional intoxication among patients were 628/937 (67.0%), 608/1,082 (56.2%), 536/1,017 (52.7), 475/987 (48.1%) from 2013 to 2016. Significant predictors identified based on decision tree analysis were alcohol consumption, old age, psychiatric disease, smoking, and male sex; those identified based on multiple regression analysis were alcohol consumption, smoking, male sex, psychiatric disease, old age, poor therapeutic adherence, and physical disease. Conclusion We identified important predictors of suicide risk by intentional intoxication. A specific and realistic approach to analysis using the decision tree modeling technique is an effective method to determine those groups at risk of suicide by intentional intoxication

A Case of Infected Left Atrial Myxoma With Concomitant Mitral Valve Endocarditis

Myxoma is the most common primary tumor in the heart. Cardiac myxomas can present in various manners including embolization and fever, sometimes simulating endocarditis. However, they are rarely infected. We report here a case of an infected left atrial myxoma that seeded a normal mitral valve and atypically presented with multiple embolic events in the lower extremities along with multiple splenic and a cerebellar infarction

The impact of sequential versus single anastomoses on flow characteristics and mid-term patency of saphenous vein grafts in coronary bypass grafting

ObjectiveTo assess the influence of bypass grafting technique on the flow characteristics and mid-term patency of saphenous vein coronary bypass grafts.MethodsIn the present study, 309 patients who underwent either sequential (group A, N = 84 grafts) or individual (group B, N = 244 grafts) saphenous vein coronary bypass grafting between February 2002 and September 2007 were investigated. Individual bypassing only was performed in 212 patients, and sequential bypassing only was performed in 78 patients. The remaining 19 patients received both. A total of 436 distal anastomoses were performed with 328 saphenous vein grafts. The intraoperative flow characteristics and the graft patency were assessed with the transit time flow meter and serial multi-detector computed tomography coronary angiograms, respectively.ResultsGroup A showed a higher mean flow compared with group B at 49.4 ± 27.4 mL/min versus 37.1 ± 20.1 mL/min, respectively (P = .001). The mean flow increased linearly as the number of anastomoses increased per graft (P < .001). Graft patency at 3 years was 93.3% ± 3.4% in group A and 86.5% ± 3.1% in group B (P = .048). After adjustment for baseline characteristics, group A showed a tendency for superior mid-term patency than group B (hazard ratio 0.362; 95% confidence interval, 0.129–1.017; P = .0538).ConclusionsSequential bypass grafts were associated with higher mean flows and superior mid-term patency compared with individual grafts. These findings suggest the more favorable results of sequential bypass grafting to be attributed to the enhanced flow hemodynamics

A case of levocetirizine-induced liver injury

Levocetirizine is a second-generation nonsedative antihistaminic agent that has been demonstrated to be safe and effective for treating allergic disease. There was only one case report of levocetirizine-induced liver toxicity, but a liver biopsy was not performed. In this article, we present the first case of levocetirizine-induced liver injury with histologic findings. A 48-year-old man was hospitalized with jaundice and generalized pruritus that had developed after 2 months of therapy with levocetirizine for prurigo nodularis. Laboratory findings revealed acute hepatitis with cholestasis. A liver biopsy demonstrated portal inflammation and hepatitis with apoptotic hepatocytes. The patient fully recovered 3 weeks after withdrawing levocetirizine. Although levocetirizine is safe and effective, physicians should be aware of its potential hepatotoxicity

Validation and Reliability of a Smartphone Application for the International Prostate Symptom Score Questionnaire: A Randomized Repeated Measures Crossover Study

Background: Smartphone-based assessment may be a useful diagnostic and monitoring tool for patients. There have been many attempts to create a smartphone diagnostic tool for clinical use in various medical fields but few have demonstrated scientific validity. Objective: The purpose of this study was to develop a smartphone application of the International Prostate Symptom Score (IPSS) and to demonstrate its validity and reliability. Methods: From June 2012 to May 2013, a total of 1581 male participants (>= 40 years old), with or without lower urinary tract symptoms (LUTS), visited our urology clinic via the health improvement center at Soonchunhyang University Hospital (Republic of Korea) and were enrolled in this study. A randomized repeated measures crossover design was employed using a smartphone application of the IPSS and the conventional paper form of the IPSS. Paired t test under a hypothesis of non-inferior trial was conducted. For the reliability test, the intraclass correlation coefficient (ICC) was measured. Results: The total score of the IPSS (P=.289) and each item of the IPSS (P=.157-1.000) showed no differences between the paper version and the smartphone version of the IPSS. The mild, moderate, and severe LUTS groups showed no differences between the two versions of the IPSS. A significant correlation was noted in the total group (ICC=.935, P<.001). The mild, moderate, and severe LUTS groups also showed significant correlations (ICC=.616,.549, and .548 respectively, all P<.001). There was selection bias in this study, as only participants who had smartphones could participate. Conclusions: The validity and reliability of the smartphone application version were comparable to the conventional paper version of the IPSS. The smartphone application of the IPSS could be an effective method for measuring lower urinary tract symptoms.X1144Ysciescopu