Opportunistic networking in OMNeT

ABSTRACT We describe mechanisms for simulating opportunistic and delay-tolerant networks in the OMNeT++ discrete event simulator. The mechanisms allow for simulating open systems of wireless mobile nodes where mobility-or contact traces are used to drive the simulations. This way mobility generation is separated from the core OMNeT++ protocol simulations which facilitates importing synthetic or real data from external mobility generators, real mobility tracking data or real contact traces. The paper describes the design and implementation of our mechanisms for OMNeT++ and gives an example of how we have used these to simulate opportunistic wireless content distribution in an urban environment

Results of immediate breast reconstructions at Landspítali-The National University Hospital of Iceland, in 2008-2010

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/Open Allur texti - Full textIn late 2007, the availability of immediate breast reconstructions increased as a result of the establishment of an oncoplastic breast surgical service at Landspítali-The National University Hospital The aim of this study was to look at the rates and early complications of immediate breast reconstructions in our hospital in 2008-2010 and compare with the results from the UK National Mastectomy and Breast Reconstruction Audit (NMBRA). This is a retrospective population-based study, including all women who had immediate breast reconstruction at Landspítali in 2008-2010. 319 mastectomies and 157 breast reconstructions were performed. Of these, 98 (62%) were immediate, (mean age 49, 29-69). The immediate breast reconstruction rate was therefore 31%, with a respective 55% for patients 50 years old or younger. In comparison, the rate was 5% in 2000-2005. Immediate reconstructions with an extended autologous latissimus dorsi flap were performed in 25 (26%) cases and implant based reconstructions in the remaining (n=73, 74%). Inpatient complications occurred in 12 (12%) patients and 5 needed reoperation (3 post-operative bleeding, 1 skin necrosis, 1 imminent LD-flap failure). Readmission due to complications after discharge occurred in 14 (14%), while 37 (38%) developed mild complications not requiring readmission. The results were comparable to NMBRA, although the rates of autologous flap reconstructions were significantly higher than in this study (63% vs. 26%). As a result of the establishment of an oncoplastic breast surgical service at Landspítali, the rates of immediate breast reconstruction have increased significantly (from 5% to 31%). The complication rates are low and similar to NMBRA.Inngangur: Möguleikar íslenskra brjóstakrabbameinssjúklinga til að gangast undir tafarlausa brjóstauppbyggingu hafa aukist verulega á undanförnum árum, einkum frá lokum árs 2007. Markmið þessarar rannsóknar var að kanna tíðni og snemmkomna fylgikvilla tafarlausra brjóstauppbygginga á Landspítala á árunum 2008-2010 og bera niðurstöðurnar saman við einu birtu rannsókn á þessu efni sem nær til heillar þjóðar og er frá Bretlandi (NMBRA). Efniviður og aðferðir: Rannsóknin er afturskyggn þýðisrannsókn á öllum konum sem gengust undir tafarlausa brjóstauppbyggingu á Landspítala á árunum 2008-2010. Niðurstöður: Heildarfjöldi brjóstnáma á tímabilinu var 319 en brjóstauppbyggingar voru 157 og af þeim voru 98 (62%) tafarlausar. Tafarlausar uppbyggingar voru því gerðar hjá 31% allra sem gengust undir brjóstnám en 55% hjá 50 ára og yngri. Til samanburðar var heildarhlutfallið 5% á árunum 2000-2005. Meðalaldur kvenna sem gengust undir tafarlausa uppbyggingu á rannsóknartímabilinu var 49 ár (29-69). Tafarlausar vöðvaflipauppbyggingar voru 25 (26%) en aðrar uppbyggingar voru gerðar með ígræði. Fylgikvillar í legu í kjölfar aðgerðar urðu eftir 12 (12%) tafarlausar uppbyggingar, þar af þurftu 5 sjúklingar enduraðgerð (þrír vegna blæðinga, einn vegna húðdreps og annar vegna yfirvofandi vöðvaflipadreps). Þörf var á endurinnlögn eftir útskrift í 14 (14%) tilfellum. Eftir útskrift urðu vægir fylgikvillar sem ekki kröfðust endurinnlagnar í 37 (38%) tilfellum. Almennt voru fylgikvillar sambærilegir og í NMBRA en flipauppbyggingar voru mun algengari í þeirri rannsókn (63% á móti 26%). Ályktun: Veruleg aukning hefur orðið á tafarlausum brjóstauppbyggingum á Landspítala (frá 5% í 31%). Almennt eru þessar aðgerðir áhættulitlar og tíðni fylgikvilla svipuð og í NMBRA

Serum biomarkers of brain injury after uncomplicated cardiac surgery: Secondary analysis from a randomized trial

BACKGROUND: Postoperative cognitive dysfunction is common after cardiac surgery. Postoperative measurements of brain injury biomarkers may identify brain damage and predict cognitive dysfunction. We describe the release patterns of five brain injury markers in serum and plasma after uncomplicated cardiac surgery. METHODS: Sixty-one elective cardiac surgery patients were randomized to undergo surgery with either a dextran-based prime or a crystalloid prime. Blood samples were taken immediately before surgery, and 2 and 24 hours after surgery. Concentrations of the brain injury biomarkers S100B, glial fibrillary acidic protein (GFAP), tau, neurofilament light (NfL) and neuron-specific enolase (NSE)) and the blood-brain barrier injury marker β-trace protein were analyzed. Concentrations of brain injury biomarkers were correlated to patients' age, operation time, and degree of hemolysis. RESULTS: No significant difference in brain injury biomarkers was observed between the prime groups. All brain injury biomarkers increased significantly after surgery (tau +456% (25th-75th percentile 327%-702%), NfL +57% (28%-87%), S100B +1145% (783%-2158%), GFAP +17% (-3%-43%), NSE +168% (106%-228%), while β-trace protein was reduced (-11% (-17-3%). Tau, S100B and NSE peaked at 2h, NfL and GFAP at 24h. Postoperative concentrations of brain injury markers correlated to age, operation time, and/or hemolysis. CONCLUSION: Uncomplicated cardiac surgery with cardiopulmonary bypass is associated with an increase in serum/plasma levels of all the studied injury markers, without signs of blood-brain barrier injury. The biomarkers differ markedly in their levels of release and time course. Further investigations are required to study associations between perioperative release of biomarkers, postoperative cognitive function and clinical outcome

Conclave: secure multi-party computation on big data (extended TR)

Secure Multi-Party Computation (MPC) allows mutually distrusting parties to run joint computations without revealing private data. Current MPC algorithms scale poorly with data size, which makes MPC on "big data" prohibitively slow and inhibits its practical use. Many relational analytics queries can maintain MPC's end-to-end security guarantee without using cryptographic MPC techniques for all operations. Conclave is a query compiler that accelerates such queries by transforming them into a combination of data-parallel, local cleartext processing and small MPC steps. When parties trust others with specific subsets of the data, Conclave applies new hybrid MPC-cleartext protocols to run additional steps outside of MPC and improve scalability further. Our Conclave prototype generates code for cleartext processing in Python and Spark, and for secure MPC using the Sharemind and Obliv-C frameworks. Conclave scales to data sets between three and six orders of magnitude larger than state-of-the-art MPC frameworks support on their own. Thanks to its hybrid protocols, Conclave also substantially outperforms SMCQL, the most similar existing system.Comment: Extended technical report for EuroSys 2019 pape

Pneumococcal vaccination: Direct and herd effect on carriage of vaccine types and antibiotic resistance in Icelandic children

Background Since the introduction of pneumococcal conjugate vaccines, vaccine type pneumococcal carriage and disease has decreased world-wide. The aim was to monitor changes in the nasopharyngeal carriage of pneumococci, the distribution of serotypes and antimicrobial resistance in children before and after initiation of the 10-valent pneumococcal vaccination in 2011, in a previously unvaccinated population. Methods Repeated cross-sectional study at 15 day-care centres in greater Reykjavik area. Nasopharyngeal swabs were collected yearly in March from 2009 to 2015. The swabs were selectively cultured for pneumococci, which were serotyped using latex agglutination and/or PCR and antimicrobial susceptibility determined. Two independent studies were conducted. In study 1, on total impact, isolates from children aged <4 years were included. The vaccine-eligible-cohort (birth-years: 2011–2013, sampled in 2013–2015) was compared with children at the same age born in 2005–2010 and sampled in 2009–2012. In study 2 on herd effect, isolates from older non-vaccine-eligible children (3.5–6.3 years) were compared for the periods before and after the vaccination (2009–2011 vs 2013–2015. Vaccine impact was determined using 1-odds-ratio. Results Following vaccination, the vaccine impact on vaccine type acquisition was 94% (95% CI: 91–96%) in study 1 and 56% (95% CI: 44–65%) in study 2. The impact on serotype 6 A was 33% (95% CI: −9%; 59%) in study 1 and 42% (95% CI: 10–63%) in study 2 with minimal effect on 19A. The non-vaccine serotypes/groups 6C, 11, 15 and 23B were the most common serotypes/groups after vaccination. Isolates from the vaccine-eligible-cohort had lower penicillin MICs, less resistance to erythromycin and co-trimoxazole and less multi resistance than isolates from the control-group. Conclusions The efficacy of the vaccination on vaccine serotypes was high, and a milder effect on vaccine-associated-serotype 6A was observed for the vaccine-eligible-cohort. There was a significant herd effect on vaccine types in older non-vaccine-eligible children. Overall antimicrobial non-susceptibility was reduced.Funding for this study was provided by GlaxoSmithKline Biologicals SA and a grant was received from the Landspitali University Hospital Research Fund. GlaxoSmithKline Biologicals SA was provided the opportunity to review a draft version of this manuscript but the authors are solely responsible for final content and interpretation. The authors received no financial support or other form of compensation related to the development of the manuscript.Peer Reviewe

Postcardiotomy Venoarterial Extracorporeal Membrane Oxygenation With and Without Intra-Aortic Balloon Pump

Publisher Copyright: © 2022 The Author(s)Objectives: To compare the outcomes of patients with postcardiotomy shock treated with venoarterial extracorporeal membrane oxygenation (VA-ECMO) only compared with VA-ECMO and intra-aortic balloon pump (IABP). Design: A retrospective multicenter registry study. Setting: At 19 cardiac surgery units. Participants: A total of 615 adult patients who required VA-ECMO from 2010 to 2018. The patients were divided into 2 groups depending on whether they received VA-ECMO only (ECMO only group) or VA-ECMO plus IABP (ECMO-IABP group). Measurements and Main Results: The overall series mean age was 63 +/- 13 years, and 33% were female. The ECMO-only group included 499 patients, and 116 patients were in the ECMO-IABP group. Urgent and/or emergent procedures were more common in the ECMO-only group. Central cannulation was performed in 47% (n = 54) in the ECMO-IABP group compared to 27% (n = 132) in the ECMO-only group. In the ECMOIABP group, 58% (n = 67) were successfully weaned from ECMO, compared to 46% (n = 231) in the ECMO-only group (p = 0.026). However, inhospital mortality was 63% in the ECMO-IABP group compared to 65% in the ECMO-only group (p = 0.66). Among 114 propensity score-matched pairs, ECMO-IABP group had comparable weaning rates (57% v 53%, p = 0.51) and in-hospital mortality (64% v 58%, p = 0.78). Conclusions: This multicenter study showed that adjunctive IABP did not translate into better outcomes in patients treated with VA-ECMO for postcardiotomy shock. (C) 2022 The Author(s). Published by Elsevier Inc.Peer reviewe

Central versus Peripheral Postcardiotomy Veno-Arterial Extracorporeal Membrane Oxygenation: Systematic Review and Individual Patient Data Meta-Analysis

Background: It is unclear whether peripheral arterial cannulation is superior to central arterial cannulation for postcardiotomy veno-arterial extracorporeal membrane oxygenation (VA-ECMO). Methods: A systematic review was conducted using PubMed, Scopus, and Google Scholar to identify studies on postcardiotomy VA-ECMO for the present individual patient data (IPD) meta-analysis. Analysis was performed according to the intention-to-treat principle. Results: The investigators of 10 studies agreed to participate in the present IPD meta-analysis. Overall, 1269 patients were included in the analysis. Crude rates of in-hospital mortality after central versus peripheral arterial cannulation for VA-ECMO were 70.7% vs. 63.7%, respectively (adjusted OR 1.38, 95% CI 1.08–1.75). Propensity score matching yielded 538 pairs of patients with balanced baseline characteristics and operative variables. Among these matched cohorts, central arterial cannulation VA-ECMO was associated with significantly higher in-hospital mortality compared to peripheral arterial cannulation VA-ECMO (64.5% vs. 70.8%, p = 0.027). These findings were confirmed by aggregate data meta-analysis, which showed that central arterial cannulation was associated with an increased risk of in-hospital mortality compared to peripheral arterial cannulation (OR 1.35, 95% CI 1.04–1.76, I2 21%). Conclusions: Among patients requiring postcardiotomy VA-ECMO, central arterial cannulation was associated with an increased risk of in-hospital mortality compared to peripheral arterial cannulation. This increased risk is of limited magnitude, and further studies are needed to confirm the present findings and to identify the mechanisms underlying the potential beneficial effects of peripheral VA-ECMO

Peripheral versus central extracorporeal membrane oxygenation for postcardiotomy shock: Multicenter registry, systematic review, and meta-analysis

BackgroundWe hypothesized that cannulation strategy in venoarterial extracorporeal membrane oxygenation (VA-ECMO) could play a crucial role in the perioperative survival of patients affected by postcardiotomy shock.MethodsBetween January 2010 and March 2018, 781 adult patients receiving VA-ECMO for postcardiotomy shock at 19 cardiac surgical centers were retrieved from the Postcardiotomy Veno-arterial Extracorporeal Membrane Oxygenation study registry. A parallel systematic review and meta-analysis (PubMed/MEDLINE, Embase, and Cochrane Library) through December 2018 was also accomplished.ResultsCentral and peripheral VA-ECMO cannulation were performed in 245 (31.4%) and 536 (68.6%) patients, respectively. Main indications for the institution VA-ECMO were failure to wean from cardiopulmonary bypass (38%) and heart failure following cardiopulmonary bypass weaning (48%). The doubly robust analysis after inverse probability treatment weighting by propensity score demonstrated that central VA-ECMO was associated with greater hospital mortality (odds ratio 1.54; 95% confidence interval, 1.09-2.18), reoperation for bleeding/tamponade (odds ratio, 1.96; 95% confidence interval, 1.37-2.81), and transfusion of more than 9 RBC units (odds ratio, 2.42; 95% confidence interval, 1.59-3.67). The systematic review provided a total of 2491 individuals with postcardiotomy shock treated with VA-ECMO. Pooled prevalence of in-hospital/30-day mortality in overall patient population was 66.6% (95% confidence interval, 64.7-68.4%), and pooled unadjusted risk ratio analysis confirmed that patients undergoing peripheral VA-ECMO had a lower in-hospital/30-day mortality than patients undergoing central cannulation (risk ratio, 0.92; 95% confidence interval, 0.87-0.98). Adjustments for important confounders did not alter our results.ConclusionsIn patients with postcardiotomy shock treated with VA-ECMO, central cannulation was associated with greater in-hospital mortality than peripheral cannulation.</p

SUSTAIN drilling at Surtsey volcano, Iceland, tracks hydrothermal and microbiological interactions in basalt 50 years after eruption

The 2017 Surtsey Underwater volcanic System for Thermophiles, Alteration processes and INnovative concretes (SUSTAIN) drilling project at Surtsey volcano, sponsored in part by the International Continental Scientific Drilling Program (ICDP), provides precise observations of the hydrothermal, geochemical, geomagnetic, and microbiological changes that have occurred in basaltic tephra and minor intrusions since explosive and effusive eruptions produced the oceanic island in 1963–1967. Two vertically cored boreholes, to 152 and 192 m below the surface, were drilled using filtered, UV-sterilized seawater circulating fluid to minimize microbial contamination. These cores parallel a 181 m core drilled in 1979. Introductory investigations indicate changes in material properties and whole-rock compositions over the past 38 years. A Surtsey subsurface observatory installed to 181 m in one vertical borehole holds incubation experiments that monitor in situ mineralogical and microbial alteration processes at 25–124 ∘C. A third cored borehole, inclined 55∘ in a 264∘ azimuthal direction to 354 m measured depth, provides further insights into eruption processes, including the presence of a diatreme that extends at least 100 m into the seafloor beneath the Surtur crater. The SUSTAIN project provides the first time-lapse drilling record into a very young oceanic basaltic volcano over a range of temperatures, 25–141 ∘C from 1979 to 2017, and subaerial and submarine hydrothermal fluid compositions. Rigorous procedures undertaken during the drilling operation protected the sensitive environment of the Surtsey Natural Preserve

Prognostic Significance of Arterial Lactate Levels at Weaning from Postcardiotomy Venoarterial Extracorporeal Membrane Oxygenation

Background: The outcome after weaning from postcardiotomy venoarterial extracorporeal membrane oxygenation (VA-ECMO) is poor. In this study, we investigated the prognostic impact of arterial lactate levels at the time of weaning from postcardiotomy VA. Methods: This analysis included 338 patients from the multicenter PC-ECMO registry with available data on arterial lactate levels at weaning from VA-ECMO. Results: Arterial lactate levels at weaning from VA-ECMO (adjusted OR 1.426, 95%CI 1.157-1.758) was an independent predictor of hospital mortality, and its best cutoff values was 1.6 mmol/L (= 1.6 mmol/L, 45.0%; adjusted OR 2.489, 95%CI 1.374-4.505). When 261 patients with arterial lactate at VA-ECMO weaning = 1.4 mmol/L, 38.5%, p = 0.014). Among 87 propensity score-matched pairs, hospital mortality was significantly higher in patients with arterial lactate >= 1.4 mmol/L (39.1% vs. 23.0%, p = 0.029) compared to those with lower arterial lactate. Conclusions: Increased arterial lactate levels at the time of weaning from postcardiotomy VA-ECMO increases significantly the risk of hospital mortality. Arterial lactate may be useful in guiding optimal timing of VA-ECMO weaning