Cost-aware optimization models for communication networks with renewable energy sources

We address a traffic engineering problem where, given a communication network and a set of origin-destination demands, we have to select a single-path routing for each demand and decide which communication interfaces to switch off or run at partial load so as to minimize the total operational costs. We account for the presence of renewable energy plants at some nodes of the network, as well as feed-in-tariffs, rebates and variable energy prices. We also consider the related problem of deciding where renewable energy sources (photovoltaic modules in this case) have to be installed so as to maximize the profit, while respecting a maximum investment budget constraint. We propose mixed integer optimization models for these two problems and we report results for two different network topologies

Surgery versus conservative antibiotic treatment in acute appendicitis: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND/AIMS: Although standard treatment typically consists of an early appendectomy, there has recently been an increase in the use of antibiotic therapy as primary treatment for acute appendicitis (AA). The aim of this analysis is to systematically evaluate the evidence available in relevant literature in order to compare the relative effectiveness of antibiotic therapy as a viable alternative to appendectomies in the treatment of AA. METHODS: Literature was searched for randomized clinical trials (RCTs) comparing the efficacy of surgery versus antibiotic therapy. Differences in pooled odds ratios (OR) for outcomes within 95% confidence intervals (CI) were calculated. RESULTS: Four RCTs were identified including 741 patients. Efficacy was significantly higher for surgery (OR = 6.01, 95% CI = 4.27-8.46). No differences were found in the numbers of perforated appendices (OR = 0.73, 95% CI = 0.29-1.84) and patients treated with antibiotics (OR = 0.04, 95% CI = 0.00-3.27). Complication rates were significantly higher for surgery (OR = 1.92, 95% CI = 1.30-2.85). CONCLUSION: Although a nonsurgical approach in AA can reduce the complications rate, the lower efficacy prevents antibiotic treatment from being a viable alternative to surgery. Since only a small number of RCTs of poor methodological quality are available, well-designed RCTs are needed for further investigation