Measuring and Analyzing Energy Consumption of the Data Center

Data centers are continuously expanding, so does the energy consumed to power their infrastructure. Server is the major component of data center’s computer rooms, which runs the most intensive computational workloads and stores the data. Server is responsible for more than a quarter of the total energy consumption of data center. This thesis is focused on analyzing and predicting the energy consumption of the server. Three major components are considered in our study; the processor, the access memory and the network interface controller. We collect data from these components and analyze them using linear regression Lasso model with non-negative coefficients. A power model is proposed for predicting energy consumption at the system-level. The model takes as input CPU cycles and data Translation Lookaside Buffer loads, and predicts the energy consumption of the server with 5.33% median error regardless of its workload

High-density lipoprotein cholesterol and multiple myeloma: A systematic review and meta-analysis

Background and aims: To systematically investigate all relevant evidence on the association between high-density lipoprotein cholesterol (HDL-C) and multiple myeloma (MM). Methods: We searched PubMed and Cochrane library databases (up to 20 September 2022) for studies with evidence on HDL-C in patients with MM. A qualitative synthesis of published prospective and retrospective studies for the role of HDL-C and other lipid profile parameters in MM was performed. Additionally, a meta-analysis on HDL-C mean differences (MD) between MM cases and controls was performed. Results: Fourteen studies (3 prospective, 11 retrospective) including 895 MM patients were eligible for this systematic review. Ten studies compared HDL-C levels in MM patients with healthy controls. In these 10 studies (n = 17,213), pooled analyses showed that MM patients had significantly lower HDL-C levels compared to healthy controls (MD: −13.07 mg/dl, 95% CI: −17.83, −8.32, p < 0.00001). Regarding secondary endpoints, total cholesterol (TC) (MD: −22.19 mg/dl, 95% CI: −39.08, −5.30) and apolipoprotein A-I (apoA-I) (−40.20 mg/dl, 95% CI: −55.00, −25.39) demonstrated significant decreases, while differences in low-density lipoprotein cholesterol (LDL-C) (MD: −11.33 mg/dl, 95% CI: −36.95, 14.30) and triglycerides (MD: 9.93 mg/dl, 95% CI: −3.40, 23.26) were not shown to be significant. Conclusions: HDL-C, as well as TC and apoA-I, levels are significantly decreased in MM. Hence, lipid profile parameters should be taken into account when assessing such patients

New insights into weaning from mechanical ventilation: left ventricular diastolic dysfunction is a key player

To investigate the diagnostic performance of Doppler echocardiography (DE) in predicting the outcome of weaning from mechanical ventilation in patients without overt cardiac disease. Fifty critical care noncardiac patients who fulfilled predetermined criteria for weaning underwent DE before and at the end of spontaneous breathing trial (pre-SBT/end-SBT, respectively). "Conventional" mitral inflow analysis and "advanced" DE parameters [tissue Doppler imaging (TDI)-derived mitral/tricuspid annular velocities and color M-mode Doppler velocity of propagation (V (p))] were used to assess left ventricular (LV) diastolic function/filling pressures. Weaning was considered successful if patients had been extubated after successful SBT and sustained spontaneous breathing for more than 48 h. Twenty-eight patients (56%) failed weaning: 23 patients failed SBT and 5 required reintubation within 48 h. Weaning failure was associated with the degree of LV diastolic dysfunction at pre-SBT (P = 0.01). Patients who failed weaning presented evidence of increased LV filling pressures at pre-SBT, by demonstrating increased E/E (m) and E/V (p) ratios compared with patients with successful outcome (P a parts per thousand currency sign 0.004); pre-SBT values of lateral E/E (m) greater than 7.8 and E/V (p) greater than 1.51 predicted weaning failure with an area under the curve, sensitivity (%), and specificity (%) of 0.86, 79, and 100, and 0.74, 75, and 73, respectively. Lateral E/E (m) was the only factor independently associated with weaning failure before SBT; OR (95% CI) 5.62 (1.17-26.96), P = 0.03. Our findings suggest that LV diastolic dysfunction is significantly associated with weaning outcome in critically ill patients with preserved LV systolic function. An E/E (m) ratio greater than 7.8 may identify patients at high risk of weaning failure