In software security, balancing the need for robust protection with performance considerations is a critical challenge. Mitigation techniques are essential to defend against various types of attacks, but they can also introduce performance overheads. Meanwhile, compilers provide optimizations that aim to enhance performance but inadvertently introduce security vulnerabilities, such as double-fetches. This thesis explores the trade-offs associated with disabling compiler optimisation options to enhance security against such vulnerabilities. By examining various optimisation levels (-O1, -O2, -O3, -Ofast) in GNU Compiler Collectio (GCC) and  LLVM compilers, we quantitatively analyse their impact on execution time, memory usage, and complexity of the binaries. Our study reveals that while opting out of optimisations can significantly improve security by eliminating double-fetch bugs, it also leads to increased execution time and larger binary sizes. These findings underscore developers' need to make informed choices about optimisations,  balancing security concerns with performance requirements. This work contributes to a deeper understanding of the security-performance trade-offs in software development and provides a foundation for further research into compiler optimisations and security.

Introduction: Coronary artery bypass grafting surgery is an effective treatment for coronary heart disease for many patients; however, evidence suggests that there are some patients who do not report a good post-operative recovery. Although several studies have begun investigating possible reasons for these observations, little is known about the impact of CABG on quality of life and there still remains a lack of information that can help clinicians identify those people more likely to experience poorer recovery so that interventions can be targeted appropriately. Aims: The overall aim was to investigate barriers to and facilitators of recovery after CABG. Method: Phase 1 was a retrospective qualitative study involving semi-structured interviews with eleven patients who had undergone CABG and with ten health professionals experienced in caring for these patients. Data were analysed using thematic analysis. Phase 2 was a prospective study comprising two components, questionnaire and interview. The questionnaire included measures of quality of life, perceived recovery, demographic and psychosocial variables and was administered prior to surgery and at six and twelve months post-surgery. A sample of ten people who completed questionnaires were interviewed at the same time points and data analysed using framework analysis. Results: Interview data described the patient experience of undergoing CABG and identified components of a good recovery from the patient perspective. Patient and health professional participants identified numerous barriers and facilitators to recovery at three key time points - prior to surgery, during the hospital inpatient stay and post-CABG - and noted the complex inter-relationships between them, thus emphasising the need for a holistic approach to investigating recovery. Questionnaire data described the pattern of psychosocial functioning, quality of life and perceived recovery across the surgical pathway and identified depression and self-efficacy as the main predictors of post-CABG quality of life and perceived recovery. Using interview and questionnaire data a model of recovery is proposed. Conclusions: Findings from this research have identified a complex inter-related network of barriers and facilitators to recovery, suggested the possible mechanisms by which they impact on post-CABG outcome and identified recommendations for clinical practice.

Seit vielen Jahren werden Glukokortikoide routinemäßig eingesetzt, um Zeichen der inflammatorischen Reaktion nach kardiochirurgischen Eingriffen unter extrakorporaler Zirkulation (EKZ) zu mildern. Glukokortikoide sind jedoch für ihre immunsuppressiven Wirkungen bekannt, und bisher blieben die möglichen Auswirkungen auf immunologische Funktionen weitgehend hypothetisch. Ziel der vorliegenden Studie war es daher, den Einfluss von Methylprednisolon (MP) und Tirilazad Mesylat (TM), einer antiinflammatorischen Substanz aus der Klasse der Aminosteroide auf immunologische Funktionen nach koronarchirurgischen Eingriffen mit EKZ zu untersuchen. 38 Patienten wurden randomisiert den Behandlungsgruppen Placebo (NaCl 0,9 %, n=13), MP (15 mg/ kg KG, n=12) und TM (10 mg/kg KG, n=13) zugeteilt. Die Verläufe der Plasmakonzentrationen von IL-6 und IL-10, der monozytären HLA-DR Expression und der ex vivo LPS-stimulierten TNF-alpha, IL-1RA, IFN-gamma und IL-12 Sekretion wurden bestimmt. Im Vergleich zu Placebo resultierte die Gabe von MP in geringeren postoperativen Plasmakonzentrationen von IL-6, aber einer deutlichen Erhöhung von IL-10. Die monozytäre HLA-DR Expression nahm postoperativ in allen Gruppen ab mit einer deutlichen Verstärkung durch MP. Die ex vivo stimulierte TNF-alpha Sekretion nahm postoperativ in allen Gruppen deutlich ab, ebenfalls mit einer deutlichen Verstärkung durch MP. Die IL-1RA Sekretion hingegen war zu keinem Zeitpunkt eingeschränkt. Die ex vivo stimulierte IFN-gamma und IL-12 war postoperativ in allen Gruppen stark vermindert ohne Einfluss einer medikamentösen Behandlung. Die Gabe von TM zeigte keinerlei Beeinflussung aller gemessenen Parameter im Vergleich zu Placebo. Nach koronarchirurgischen Eingriffen sind insbesondere monozytäre Funktionen stark eingeschränkt. Diese Suppression wird durch die Gabe von MP verstärkt, während die Gabe von TM nicht in einer zusätzlichen Immunsuppression resultiert. IL-10 scheint eine Schlüsselrolle bei der beobachteten monozytären Funktionseinschränkung einzunehmen. / Glucocorticoids have been routinely applied in cardiac surgery involving cardiopulmonary bypass (CPB) for many years in order to diminish inflammatory stress reactions. On the other hand glucocorticoids are well known for their immunosuppressive effects, and data on the consequences on immune function are scarce. Thus it was the aim of this trial to determine the influence of methylprednisolone (MP) and tirilazad mesylate (TM), an antiinflammatory drug of the class of aminosteroids, on immunological parameters after coronary surgery involving CPB. 38 patients were randomised to receive either placebo (NaCl 0.9 %, n=13), MP (15 mg/kg, n=12) or TM (10 mg/kg, n=13) treatment. Plasma concentrations of IL-6 and IL-10, monocyte surface expression of HLA-DR and the ex vivo endotoxin-stimulated secretion of TNF-alpha, IL-1RA, IFN-gamma und IL-12 were measured. Compared to placebo IL-6 concentrations were lower after MP treatment, whereas IL-10 levels were much higher. The rate of HLA-DR+-monocytes decreased in all groups with a significant aggravation by MP treatment. The ex vivo stimulated TNF-alpha secretion was postoperatively diminished in all groups, with again significantly lower values after MP treatment. IL-1RA secretion was not suppressed at any point. The ex vivo stimulated IFN-gamma and IL-12 secretion was strongly suppressed postoperatively regardless of the treatment. TM treatment resulted in no alterations of any parameter measured. It was demonstrated that especially monocyte functions are depressed after coronary surgery, and that MP treatment results in marked aggravation of this immunosuppression, whereas TM treatment shows no additional immunosuppressive effect. IL-10 seems to play a key role in the observed monocyte functional depression.

Background: Despite the recent improvements in surgical techniques and postoperative patient care, atrial fibrillation (AF) remains the most frequent complication after cardiac surgery. Although postoperative AF is often regarded as a benign clinical condition, this arrhythmia has significant adverse effects on patient recovery and postoperative survival. Its exact pathophysiology has not yet been elucidated. The present thesis aims to analyze AF risk factors and their interaction, pre-existing histological explanatory alterations of the atrium, the AF impact on postoperative survival and the compliance of a prophylactic drug regimen. Methods: During a 10-year period, consecutive cardiac surgery cases with complete data on AF occurrence and postoperative survival were extracted. All patients were operated on for coronary or valvular surgery, with cardiopulmonary bypass (CPB). Hospital and long-term survival data were obtained from Swedish population registry. Study I) Isolated coronary artery bypass grafting (CABG, n=7056), aortic valve replacement (n=690) and their combination (n=688) were considered. Independent AF risk factors and AF effects on early and 1 year mortality were investigated. Study II) Patients affected by postoperative AF among isolated CABG patients (n=7621), valvular surgeries (n=995) and their combination (n=879) were studied. Long-term survival was obtained and prognostic factors identified. Study III) Seventy patients were randomized to on-pump (n=35) or off-pump (n=35) CABG. Samples from the right atrial appendage were collected and histology was evaluated by means of light and electronic microscopy with reference to preexistent alterations related to postoperative AF. Study IV) Cardiac surgery patients with complete data on smoking status (n=3245) were reviewed. Effects of smoking on AF development and interaction among variables were explored. Study V) CABG patients without clinical contraindications to receive oral sotalol (80 mg twice daily) and magnesium were prospectively enrolled (n = 49) and compared with a matched contemporary control CABG group (n = 844). The clinical compliance to the AF prophylactic drug regimen was tested. Results: The overall AF incidence was around 26%, subdivided into 23%, 40% and 45% for isolated CABG, valve procedures and their combined surgeries, respectively. Age was the strongest predictor of postoperative AF. Coronary disease superimposed risk factors with reference to myocardial conditions at CPB weaning. Considering the preoperative smoking condition, smokers demonstrated a reduced AF incidence compared to non-smokers (20% versus 27%, p<0.001). An interaction between smoking status and inotropic support was observed: without this interaction smoking conferred a 46% risk reduction of AF (p=0.011). At the histological level, myocyte vacuolization and nuclear derangement represented anatomical independent AF predictors (p=0.002 and p=0.016, respectively). CPB exposure was not associated to postoperative AF nor histological changes. Although, postoperative AF increases the length of hospitalization in all patient groups, it did not affect the hospital survival. However, AF independently impaired the late survival, a phenomenon seen in the CABG group only. With reference to the tested sotalolmagnesium drug regimen, only 55% of CABG patients were compliant to the treatment, with marginal effects on AF occurrence. Conclusions: In addition to age, details at the CPB weaning period, pre-existing histopathological changes, the hyperadrenergic state and catecholamines are key mechanisms in the pathophysiology of postoperative AF. In particular, the CPB period hides valuable information for timely AF prophylactic stratifications. Further, compliance effects due to patient selection should also be considered in a prophylactic therapy model. Postoperative AF increases late mortality after isolated CABG surgery, but not after valvular procedures. Although the mechanisms are unclear, our results draw the attention to possible AF recurrence after hospital discharge, indicating a strict postoperative surveillance.

Dagens samhälle kräver att varje enskild individ måste ta beslut över alla de val som vi ställs inför. När det gäller val som antingen gynnar eller missgynnar vår hälsa är möjligheterna idag oändliga. På grund av detta finns det många som ökar i vikt och därmed kan behöva hjälp med att göra en livsstilsförändring. Syftet med denna studie var att undersöka vilka faktorer som kan ha påverkat och motiverat i valet av att göra en gastric bypass operation, samt att urskilja vilka förändringar som följer efter den typen av livsstilsförändring. Semistrukturerade intervjuer genomfördes där fyra informanter deltog och studiens data analyserades med en kvalitativ innehållsanalys. Resultatet skrevs fram med tre huvudkategorier: Livet innan operationen, Faktorer som påverkat och motiverat till att välja gastric bypass samt Livet efter operationen. Detta visade att informanterna motiverades av deras oro inför den framtida hälsan samt deras förhoppningar om en förändrad framtid, det visade också att deras val påverkades av omgivningen. Sinnesstämningen och den sociala tillhörigheten hade förbättrats efter operationen och livskvaliteten hade ökat. / Today's society requires that each individual has to take decisions on all the choices that we face. When it comes to choices that either benefit or disadvantage our health the possibilities are endless. As a result of this there is a large part of the population that has increased in weight and might need help in making lifestyle changes. The purpose of this study was to investigate the factors that may have influenced and motivated the choice of going through a gastric bypass surgery, and to discern which changes following that kind of lifestyle change. Semi-structured interviews with the four participants were conducted, data were analyzed using qualitative content analysis. The result was partitioned into three main categories: Life before surgery, Factors that influenced and motivated to choose gastric bypass and Life after surgery. The findings displayed that the participants were motivated by their concern for the future health and their hopes for a changed future, the findings also showed that their choice was influenced by the surroundings. The surgery led to an improvement in mood and social life as well as an increase in quality of life for the participants.

Thesis (D.P.H.)--University of Michigan.

Thesis (D.P.H.)--University of Michigan.

Thesis (M.Sc.)--Memorial University of Newfoundland, 2003. / Restricted until October 2004. Bibliography: leaves 95-101.

Abstract The identification of risk factors for major adverse events after coronary artery bypass surgery is of main importance as it allows outcome prediction, facilitates preoperative patient selection and improves the quality of care. In the present clinical studies we have evaluated the impact of preoperative angiographic severity of a coronary artery disease and preoperative C-reactive protein (CRP) on the immediate outcome after coronary artery bypass surgery. We have reviewed the results of off-pump (OPCAB) versus conventional on-pump coronary artery bypass surgery (CCAB) in high risk patients. We have evaluated the impact of postoperative pulmonary artery blood temperature on the immediate outcome as well. In addition, we have investigated the incidence, timing and outcome of an atrial fibrillation (AF) related stroke after surgery. The multivariate analysis showed that among 2233 patients, the overall coronary angiographic score was predictive of postoperative death (p = 0.03; OR 1.027, 95% CI: 1.003–1.052) and of a low cardiac output syndrome (p = 0.04; OR 1.172, 95% CI: 1.010–1.218). The poor status of the proximal segment of the left circumflex coronary artery, the diagonal branches and the left obtuse marginal artery were most closely associated with adverse postoperative outcome. Patients (114/764) with a preoperative serum concentration of CRP ≥ 1.0 mg/dL had a higher risk of overall postoperative death (5.3% vs. 1.1%, p = 0.001), cardiac death (4.4% vs. 0.8%, p = 0.002), a low cardiac output syndrome (8.8% vs. 3.7%, p = 0.01). Among 179 high risk patients with an additive EuroSCORE6, the 30-day postoperative death and stroke rates were 7.5% and 6.0% in the OPCAB group, and 5.4% (p = 0.75) and 8.0% (p = 0.77) in the CCAB group, respectively. No significant differences were observed in other major outcome end-points between these non-randomised groups either. High pulmonary artery blood temperature on admission to the ICU among 1639 patients was significantly associated with an increased risk of overall postoperative death (p = 0.002), cardiac death (p = 0.03), and a low cardiac output syndrome (p < 0.0001), and was significantly correlated with prolonged length of the ICU stay (r = 0.095; p < 0.0001), and postoperative bleeding (ρ = –0.091; p = 0.001). Among 2,630 patients who underwent coronary artery bypass grafting (CABG), 52 (2.0%) experienced a postoperative stroke. Twelve out of these 52 patients (23.1%) died postoperatively. The ischemic cerebral event occurred after a mean of 3.7 days (0–33). In 19 patients (36.5%), atrial fibrillation preceded the occurrence of neurological complication. The angiographic severity of the coronary artery disease and the preoperative serum concentration of CRP predict postoperative outcome after a CABG operation. OPCAB can be performed safely in high-risk patients with results as satisfactory as those achieved with CCAB. CABG patients with a high pulmonary artery blood temperature on admission to the ICU seem to have a higher risk of postoperative adverse events. Atrial fibrillation occurring after coronary artery bypass grafting is a major determinant of a postoperative stroke.

Hjärt- och kärlsjukdomar är den största dödsorsaken i världen. En av behandlingarna som kan ges vid detta är koronar bypass operation. Väntan inför denna operation kan upplevas oviss och skapa oro hos patienten. Syftet med litteraturstudien var att undersöka patientens upplevelse i väntan på koronar bypass operation. Metod: Studien genomfördes som en allmän strukturerad litteraturstudie med induktiv ansats där sex kvalitativa, en kvantitativ samt en artikel med mixad metod erhölls. Data bearbetades genom en innehållsanalys. Resultat: Resultatet visade att patienter upplever såväl emotionell som somatisk påfrestning i väntan på koronar bypass operation. De mest framträdande upplevelserna var att patienterna upplevde ängslan och oro, ovisshet, rädsla och fysiska restriktioner. Dessa upplevelser mynnade ut till två teman den emotionella väntan och den somatiska väntan. Konklusion: I väntan på koronar bypass operation var de mest framträdande upplevelserna ovisshet samt ängslan och oro. För att reducera ovissheten, ängslan och oron var det av största vikt att sjuksköterskan arbetade personcentrerat. En sjuksköterskeledd intervention samt möjlighet att prata med tidigare koronar bypass operation patienter visade en signifikant reducering av den emotionella påfrestningen. En ökad förståelse för patienters upplevelse i väntan på koronar bypass operation är av stor vikt för att möjliggöra personcentrerad omvårdnad. / Cardiovascular disease is the leading cause of death in the world. One of the treatments for this is to undergo a coronary artery bypass graft. The waiting time before surgery causes uncertainty and worry in some patients. The aim was to examine patients’ experience while waiting for coronary artery bypass. The Method used was a general structured literature study with an inductive approach, where sixarticles with a qualitative approach, one quantitative and one with mixed method were found. The data was processed through a content analysis. The Result showed that patients experience both emotional and somatic stress while waiting for coronary artery bypass surgery. The most dominant experiences and emotions that patients felt were anxiety, uncertainty, fear, and physical restrictions. These experiences and emotions resulted in two themes Emotional waiting and Somatic waiting. TheConclusion showed to reduce uncertainty and anxiety it was of the utmost importance that the nurse applied person-centered care. A nurse-led intervention as well as the opportunity to talk with former coronary artery bypass patients showed a significant reduction in emotional strain. An increased understanding of patient´s experience while waiting for coronary artery bypass is of great importance to enable person-centered care.