Correlation-Aware Virtual Machine Allocation for Energy-Efficient Datacenters

Server consolidation plays a key role to mitigate the continuous power increase of datacenters. The recent advent of scale-out applications (e.g., web search, MapReduce, etc.) necessitate the revisit of existing server consolidation solutions due to distinctively different characteristics compared to traditional high-performance computing (HPC), i.e., user interactive, latency critical, and operations on large data sets split across a number of servers. This paper presents a power saving solution for datacenters that especially targets the distinctive characteristics of the scale-out applications. More specifically, we take into account correlation information of core utilization among virtual machines (VMs) in server consolidation to lower actual peak server utilization. Then, we utilize this reduction to achieve further power savings by aggressively-yet-safely lowering the server operating voltage and frequency level. We have validated the effectiveness of the proposed solution using 1) multiple clusters of real-life scale-out application workloads based web search and 2) utilization traces obtained from real datacenter setups. According to our experiments, the proposed solution provides up to 13.7% power savings with up to 15.6% improvement of Quality-of-Service (QoS) compared to existing correlation-aware VM allocation schemes for datacenters

Frequency of and Risk Factors for Depression among Participants in the Swiss HIV Cohort Study (SHCS).

OBJECTIVES: We studied the incidence and prevalence of, and co-factors for depression in the Swiss HIV Cohort Study. METHODS: Depression-specific items were introduced in 2010 and prospectively collected at semiannual cohort visits. Clinical, laboratory and behavioral co-factors of incident depression among participants free of depression at the first two visits in 2010 or thereafter were analyzed with Poisson regression. Cumulative prevalence of depression at the last visit was analyzed with logistic regression. RESULTS: Among 4,422 participants without a history of psychiatric disorders or depression at baseline, 360 developed depression during 9,348 person-years (PY) of follow-up, resulting in an incidence rate of 3.9 per 100 PY (95% confidence interval (CI) 3.5-4.3). Cumulative prevalence of depression during follow-up was recorded for 1,937/6,756 (28.7%) participants. Incidence and cumulative prevalence were higher in injection drug users (IDU) and women. Older age, preserved work ability and higher physical activity were associated with less depression episodes. Mortality (0.96 per 100 PY, 95% CI 0.83-1.11) based upon 193 deaths over 20,102 PY was higher among male IDU (2.34, 1.78-3.09), female IDU (2.33, 1.59-3.39) and white heterosexual men (1.32, 0.94-1.84) compared to white heterosexual women and homosexual men (0.53, 0.29-0.95; and 0.71, 0.55-0.92). Compared to participants free of depression, mortality was slightly elevated among participants with a history of depression (1.17, 0.94-1.45 vs. 0.86, 0.71-1.03, P = 0.033). Suicides (n = 18) did not differ between HIV transmission groups (P = 0.50), but were more frequent among participants with a prior diagnosis of depression (0.18 per 100 PY, 95%CI 0.10-0.31; vs. 0.04, 0.02-0.10; P = 0.003). CONCLUSIONS: Depression is a frequent co-morbidity among HIV-infected persons, and thus an important focus of care

Ribavirin Concentrations Do Not Predict Sustained Virological Response in HIV/HCV-Coinfected Patients Treated with Ribavirin and Pegylated Interferon in the Swiss HIV Cohort Study.

BACKGROUND: Ribavirin (RBV) is an essential component of most current hepatitis C (HCV) treatment regimens and still standard of care in the combination with pegylated interferon (pegIFN) to treat chronic HCV in resource limited settings. Study results in HIV/HCV-coinfected patients are contradicting as to whether RBV concentration correlates with sustained virological response (SVR). METHODS: We included 262 HCV treatment naïve HIV/HCV-coinfected Swiss HIV Cohort Study (SHCS) participants treated with RBV and pegIFN between 01.01.2001-01.01.2010, 134 with HCV genotype (GT) 1/4, and 128 with GT 2/3 infections. RBV levels were measured retrospectively in stored plasma samples obtained between HCV treatment week 4 and end of therapy. Uni- and multivariable logistic regression analyses were used to evaluate the association between RBV concentration and SVR in GT 1/4 and GT 2/3 infections. The analyses were repeated stratified by treatment phase (week 4-12, 13-24, >24) and IL28B genotype (CC versus CT/TT). RESULTS: SVR rates were 35.1% in GT 1/4 and 70.3% in GT 2/3 infections. Overall, median RBV concentration was 2.0 mg/L in GT 1/4, and 1.9 mg/L in GT 2/3, and did not change significantly across treatment phases. Patients with SVR had similar RBV concentrations compared to patients without SVR in both HCV genotype groups. SVR was not associated with RBV levels ≥2.0 mg/L (GT 1/4, OR 1.19 [0.5-2.86]; GT 2/3, 1.94 [0.78-4.80]) and ≥2.5 mg/L (GT 1/4, 1.56 [0.64-3.84]; GT 2/3 2.72 [0.85-8.73]), regardless of treatment phase, and IL28B genotype. CONCLUSION: In HIV/HCV-coinfected patients treated with pegIFN/RBV, therapeutic drug monitoring of RBV concentrations does not enhance the chance of HCV cure, regardless of HCV genotype, treatment phase and IL28B genotype

Hepatitis C infection and the risk of non-liver-related morbidity and mortality in HIV-positive persons in the Swiss HIV Cohort Study.

BACKGROUND HCV infection has been associated with increased non-liver-related morbidity and mortality. However, studies have yielded inconsistent results. METHODS The incidence of clinical events in HIV-infected HCV-seropositive and incidence-density-matched HCV-seronegative participants of the Swiss HIV Cohort Study from 08/1994 to 12/2014 was studied. We compared firstly, HCV-seropositive with HCV-seronegative participants, and secondly, HCV-viremic with successfully treated nonviremic patients. Poisson regression was used to assess differences between these groups. RESULTS We included 2503 HCV-seropositive participants, 540 with spontaneous HCV-clearance, 1294 untreated HCV-RNA-positive, 345 treated with SVR, 281 treated without SVR, and 2503 HCV-seronegative controls. After a mean follow-up of 8.2 years, we observed 107/18 (HCV-seropositive/HCV-seronegative) liver events, 41/14 kidney events, 230/121 osteoporosis/fractures, 82/94 diabetes mellitus, 114/129 cardiovascular events, 119/147 non-AIDS malignancies, 162/126 HIVCDC B/C events, 106/10 liver-related deaths, and 227/218 non-liver-related deaths. Compared to HCV-negative controls, HCV-seropositive participants had an increased risk of liver events (IRR 6.29[95% CI 3.52-11.22]), liver-related death (8.24[3.61-18.83]), kidney events (2.43[1.11-5.33]), and osteoporosis/fracture (1.43[1.03-2.01]). Among HCV-seropositive individuals, treated participants without SVR versus those with SVR had a higher risk of liver events (6.79[2.33-19.81]), liver-related death (3.29[1.35-8.05]), and diabetes mellitus (4.62[1.53-13.96]). Similar but not statistically significant differences were found between untreated HCV-RNA positive patients and those with SVR. CONCLUSIONS While HCV-exposure was associated with an increased risk of kidney disease and osteoporosis/fracture, this risk did not seem to be dependent of persistent HCV-RNA. Successful HCV treatment was associated with a lower incidence of liver disease, liver-related death and diabetes mellitus while the other conditions studied were less affected

Hepatitis C Infection and the Risk of Non-Liver-Related Morbidity and Mortality in HIV-Infected Persons in the Swiss HIV Cohort Study

Background: Hepatitis C virus (HCV) infection has been associated with increased non-liver-related morbidity and mortality. However, studies have yielded inconsistent results. Methods: The incidence of clinical events in human immunodeficiency virus (HIV)–infected HCV-seropositive and incidence density–matched HCV-seronegative participants of the Swiss HIV Cohort Study from August 1994 to December 2014 was studied. We compared (1) HCV-seropositive with HCV-seronegative participants and (2) HCV-viremic with successfully treated nonviremic patients. Poisson regression was used to assess differences between these groups. Results: We included 2503 HCV-seropositive participants (540 with spontaneous HCV clearance, 1294 untreated HCV RNA positive, 345 treated with sustained virologic response [SVR], 43 during treatment, and 281 treated without SVR), and 2503 HCV-seronegative controls. After a mean follow-up of 8.2 years, we observed (HCV seropositive and HCV seronegative, respectively) 107 and 18 liver events, 41 and 14 kidney events, 230 and 121 osteoporosis/fractures, 82 and 94 diabetes mellitus, 114 and 129 cardiovascular events, 119 and 147 non-AIDS malignancies, 162 and 126 Centers for Disease Control and Prevention HIV category B/C events, 106 and 10 liver-related deaths, and 227 and 218 non-liver-related deaths. Compared with HCV-negative controls, HCV-seropositive participants had an increased risk of liver events (incidence rate ratio [IRR], 6.29 [95% confidence interval {CI}, 3.52–11.22]), liver-related death (IRR, 8.24 [95% CI, 3.61–18.83]), kidney events (IRR, 2.43 [95% CI, 1.11–5.33]), and osteoporosis/fracture (IRR, 1.43 [95% CI, 1.03–2.01]). Among HCV-seropositive individuals, treated participants without SVR vs those with SVR had a higher risk of liver events (IRR, 6.79 [95% CI, 2.33–19.81]), liver-related death (IRR, 3.29 [95% CI, 1.35–8.05]), and diabetes mellitus (IRR, 4.62 [95% CI, 1.53–13.96]). Similar but not statistically significant differences were found between untreated HCV RNA–positive patients and those with SVR. Conclusions: While HCV exposure was associated with an increased risk of kidney disease and osteoporosis/fracture, this risk did not seem to be dependent of persistent HCV RNA. Successful HCV treatment was associated with a lower incidence of liver disease, liver-related death, and diabetes mellitus, whereas the other conditions studied were less affected

Weight and Metabolic Changes After Switching From Tenofovir Disoproxil Fumarate to Tenofovir Alafenamide in People Living With HIV : A Cohort Study

BACKGROUND Tenofovir-based antiretroviral therapy (ART) has become first-line in all major HIV treatment guidelines. Compared with tenofovir disoproxil fumarate (TDF), tenofovir alafenamide (TAF) has a favorable renal and bone safety profile, but concerns about metabolic complications remain. OBJECTIVE To assess weight changes, the development of overweight/obesity, and changes in lipid levels 18 months after replacing TDF with TAF. DESIGN Cohort study. SETTING 5 university hospitals, affiliated hospitals, and private physicians in Switzerland. PARTICIPANTS 4375 adults living with HIV who received TDF-containing ART for 6 months or longer. MEASUREMENTS Changes in weight and lipid levels were assessed using mixed-effect models. Differences in proportions of newly overweight/obese participants were calculated using 2-proportions Z tests. RESULTS 4375 individuals were included, with follow-up between 1 January 2016 and 31 July 2019. Median age was 50 years (interquartile range, 43 to 56 years), 25.9% were female, and 51.7% had a normal body mass index (BMI); 3484 (79.6%) switched to TAF and 891 (20.4%) continued TDF. After 18 months, switching to TAF was associated with an adjusted mean weight increase of 1.7 kg (95% CI, 1.5 to 2.0 kg), compared with 0.7 kg (CI, 0.4 to 1.0 kg) with the continued use of TDF (between-group difference, 1.1 kg [CI, 0.7 to 1.4 kg]). Among individuals with a normal BMI, 13.8% who switched to TAF became overweight/obese, compared with 8.4% of those continuing TDF (difference, 5.4 percentage points [CI, 2.1 to 8.8 percentage points]). Switching to TAF led to increases in adjusted mean total cholesterol (0.25 mmol/L [9.5 mg/dL]), high-density lipoprotein cholesterol (0.05 mmol/L [1.9 mg/dL]), low-density lipoprotein cholesterol (0.12 mmol/L [4.7 mg/dL]), and triglyceride (0.18 mmol/L [16.1 mg/dL]) levels after 18 months. LIMITATION Short follow-up, small subgroup analyses, and potential residual confounding. CONCLUSION Replacing TDF with TAF is associated with adverse metabolic changes, including weight increase, development of obesity, and worsening serum lipid levels. PRIMARY FUNDING SOURCE Swiss National Science Foundation

Changes in renal function after switching from TDF to TAF in HIV-infected individuals: a prospective cohort study

BACKGROUND: Replacing tenofovir disoproxil fumarate (TDF) with tenofovir alafenamide (TAF) improves renal tubular markers in HIV-infected individuals but the impact on estimated glomerular filtration rate (eGFR) remains unclear. METHODS: In all participants from the Swiss HIV Cohort Study who switched from TDF to TAF-containing antiretroviral regimen or continued TDF, we estimated changes in eGFR and urine protein-to-creatinine ratio (UPCR) after 18 months using mixed-effect models. RESULTS: Of 3520 participants (26.6% women, median age 50 years), 2404 (68.5%) switched to TAF. Overall, 1664 (47.3%) had an eGFR <90 mL/min and 1087 (30.9%) an UPCR ≥15 mg/mmol. In patients with baseline eGFR ≥90 mL/min, eGFR decreased with the use of TDF and TAF (-1.7 mL/min). Switching to TAF was associated with increases in eGFR of 1.5 mL/min (95% confidence interval [CI], .5-2.5) if the baseline eGFR was 60-89 mL/min, and 4.1 mL/min (95% CI, 1.6-6.6) if <60 mL/min. In contrast, eGFR decreased by 5.8 mL/min (95% CI, 2.3-9.3) with continued use of TDF in individuals with baseline eGFR <60 mL/min. UPCR decreased after replacing TDF by TAF, independent of baseline eGFR. CONCLUSIONS: Switching from TDF to TAF improves eGFR and proteinuria in patients with renal dysfunction

Weight and Metabolic Changes After Switching From Tenofovir Disoproxil Fumarate to Tenofovir Alafenamide in People Living With HIV : A Cohort Study.

BACKGROUND Tenofovir-based antiretroviral therapy (ART) has become first-line in all major HIV treatment guidelines. Compared with tenofovir disoproxil fumarate (TDF), tenofovir alafenamide (TAF) has a favorable renal and bone safety profile, but concerns about metabolic complications remain. OBJECTIVE To assess weight changes, the development of overweight/obesity, and changes in lipid levels 18 months after replacing TDF with TAF. DESIGN Cohort study. SETTING 5 university hospitals, affiliated hospitals, and private physicians in Switzerland. PARTICIPANTS 4375 adults living with HIV who received TDF-containing ART for 6 months or longer. MEASUREMENTS Changes in weight and lipid levels were assessed using mixed-effect models. Differences in proportions of newly overweight/obese participants were calculated using 2-proportions Z tests. RESULTS 4375 individuals were included, with follow-up between 1 January 2016 and 31 July 2019. Median age was 50 years (interquartile range, 43 to 56 years), 25.9% were female, and 51.7% had a normal body mass index (BMI); 3484 (79.6%) switched to TAF and 891 (20.4%) continued TDF. After 18 months, switching to TAF was associated with an adjusted mean weight increase of 1.7 kg (95% CI, 1.5 to 2.0 kg), compared with 0.7 kg (CI, 0.4 to 1.0 kg) with the continued use of TDF (between-group difference, 1.1 kg [CI, 0.7 to 1.4 kg]). Among individuals with a normal BMI, 13.8% who switched to TAF became overweight/obese, compared with 8.4% of those continuing TDF (difference, 5.4 percentage points [CI, 2.1 to 8.8 percentage points]). Switching to TAF led to increases in adjusted mean total cholesterol (0.25 mmol/L [9.5 mg/dL]), high-density lipoprotein cholesterol (0.05 mmol/L [1.9 mg/dL]), low-density lipoprotein cholesterol (0.12 mmol/L [4.7 mg/dL]), and triglyceride (0.18 mmol/L [16.1 mg/dL]) levels after 18 months. LIMITATION Short follow-up, small subgroup analyses, and potential residual confounding. CONCLUSION Replacing TDF with TAF is associated with adverse metabolic changes, including weight increase, development of obesity, and worsening serum lipid levels. PRIMARY FUNDING SOURCE Swiss National Science Foundation

HIV viral load as an independent risk factor for tuberculosis in South Africa: collaborative analysis of cohort studies

Introduction: Chronic immune activation due to ongoing HIV replication may lead to impaired immune responses against opportunistic infections such as tuberculosis (TB). We studied the role of HIV replication as a risk factor for incident TB after starting antiretroviral therapy (ART)