Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease

Background: Experimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. Methods: We conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1β, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. RESULTS: At 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in the 300-mg group than in the placebo group. Canakinumab did not reduce lipid levels from baseline. At a median follow-up of 3.7 years, the incidence rate for the primary end point was 4.50 events per 100 person-years in the placebo group, 4.11 events per 100 person-years in the 50-mg group, 3.86 events per 100 person-years in the 150-mg group, and 3.90 events per 100 person-years in the 300-mg group. The hazard ratios as compared with placebo were as follows: in the 50-mg group, 0.93 (95% confidence interval [CI], 0.80 to 1.07; P = 0.30); in the 150-mg group, 0.85 (95% CI, 0.74 to 0.98; P = 0.021); and in the 300-mg group, 0.86 (95% CI, 0.75 to 0.99; P = 0.031). The 150-mg dose, but not the other doses, met the prespecified multiplicity-adjusted threshold for statistical significance for the primary end point and the secondary end point that additionally included hospitalization for unstable angina that led to urgent revascularization (hazard ratio vs. placebo, 0.83; 95% CI, 0.73 to 0.95; P = 0.005). Canakinumab was associated with a higher incidence of fatal infection than was placebo. There was no significant difference in all-cause mortality (hazard ratio for all canakinumab doses vs. placebo, 0.94; 95% CI, 0.83 to 1.06; P = 0.31). Conclusions: Antiinflammatory therapy targeting the interleukin-1β innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid-level lowering. (Funded by Novartis; CANTOS ClinicalTrials.gov number, NCT01327846.

On the performance anomaly in WiMAX networks

The WiMAX system carries a wide range of services in urban and rural environments supporting quality of service. A key element of the QoS framework is the scheduling algorithm adopted by the Base Station (BS). In this paper, we analyze the saturation throughput perceived by Mobile Stations in the cases of two BS scheduling algorithms: Deficit Round Robin (DRR) and time-based DRR. We demonstrate that theWiFi issue of ‘Performance Anomaly’ also occurs in WiMAX networks: when the BS uses scheduling approaches aimed at achieving throughputfairness, like DRR. Performance Anomaly means that when some Mobile Stations (MSs) use a very low bit rate, the throughput of MSs with a high bit rate is dramatically degraded. We propose time-based DRR as a viable solution to remove the Performance Anomaly. Time-based DRR is a simple modification of the DRR algorithm that achieves time-fairness. Its implementation is feasible in WiMAX. The analysis is carried out by means of analytical models supported by NS2 simulations. Two scenarios are considered: the first is suitably set up to highlight and understand the phenomenon of Performance Anomaly; the second examines the impact of Performance Anomaly on a system level focusing on a rural environment

On the performance anomaly in WiMAX networks

The WiMAX system carries a wide range of services in urban and rural environments supporting quality of service. A key element of the QoS framework is the scheduling algorithm adopted by the Base Station (BS). In this paper, we analyze the saturation throughput perceived by Mobile Stations in the cases of two BS scheduling algorithms: Deficit Round Robin (DRR) and time-based DRR. We demonstrate that theWiFi issue of ‘Performance Anomaly’ also occurs in WiMAX networks: when the BS uses scheduling approaches aimed at achieving throughputfairness, like DRR. Performance Anomaly means that when some Mobile Stations (MSs) use a very low bit rate, the throughput of MSs with a high bit rate is dramatically degraded. We propose time-based DRR as a viable solution to remove the Performance Anomaly. Time-based DRR is a simple modification of the DRR algorithm that achieves time-fairness. Its implementation is feasible in WiMAX. The analysis is carried out by means of analytical models supported by NS2 simulations. Two scenarios are considered: the first is suitably set up to highlight and understand the phenomenon of Performance Anomaly; the second examines the impact of Performance Anomaly on a system level focusing on a rural environment

Wireless Opportunistic Network Based on UWB for Preserving Environment

In last years, research on developing sensing devices allows new applications for preserving the environment. A typical application foresees to collect data through sensors deployed in the desired area. We proposed to use Ultrawideband (UWB) technology to provide connectivity among sensors enabling the collecting site (the sink) to store environmental parameters. When necessary those parameters are transmitted to the remote monitoring site. The main problems of sensor network is from one side to have a large number of nodes to guarantee a high connectivity level and on the other side not to have a harmful interference on licensed primary users (PUs), with which UWBs share the same bandwidth. In this paper, we propose a deployment strategy for sensors in an open outdoor area. The methodology takes into account both connectivity and coexistence issues envisaged in the deployment phase. Results show that a certain connectivity level can be reached depending on the number of sensors in the area and on propagation conditions. Moreover, an analysis on coexistence between UWBs and PUs is performed depending on the number of PUs in the same area to be preserved and the bit rate required by the application

Impact of control channel design on cooperative spectrum sensing in opportunistic spectrum access networks

In Opportunistic Spectrum Access (OSA) networks, Secondary unlicensed Users (SUs) need a common Control Channel (CC) to identify the spectrum opportunities, i.e., common spectrum holes unused by licensed Primary Users (PUs). Typically, an interference-free CC is unrealistically assumed in the literature. In this paper we evaluate the impact of the availability and the characteristics of the CC on the performance of cooperative spectrum sensing. We deal with the dimensioning of an underlay Ultra-wideband (UWB) signalling network for the exchange of sensing data among secondary Cognitive Radio (CR) nodes avoiding harmful interference to PUs. To this aim, we analyse the trade-off between the connectivity degree of a multihop underlay UWB signalling network, directly related to the possibility to perform cooperative sensing, and its coexistence with PUs. It is observed that the correct dimensioning of the UWB signalling network allows to achieve high accuracy of PU detection without compromising primary systems

Performance Evaluation of an Opportunistic Distributed Power Control Procedure for Wireless Multiple Access

In wireless ad hoc networks, effective spatial channel reuse can maximize the achievable throughput. To this aim, power-controlled multiple access MAC protocols seems to be a viable solution to allow a greater number of simultaneous transmissions on the same channel. In this paper, we propose an opportunistic distributed algorithm to increase throughput in ad-hoc networks by exploiting the spatial reuse deriving from the implementation of power controlled data transmissions. Performance is evaluated through simulation. Results show that a marked improvement of the aggregate channel utilization can be achieved with respect to the no power control schemes (such as in the typical IEEE 802.11 systems) by properly selecting the link margins for fading and interference