Traffic Analysis Resistant Infrastructure

Network traffic analysis is using metadata to infer information from traffic flows. Network traffic flows are the tuple of source IP, source port, destination IP, and destination port. Additional information is derived from packet length, flow size, interpacket delay, Ja3 signature, and IP header options. Even connections using TLS leak site name and cipher suite to observers. This metadata can profile groups of users or individual behaviors. Statistical properties yield even more information. The hidden Markov model can track the state of protocols where each state transition results in an observation. Format Transforming Encryption (FTE) encodes data as the payload of another protocol. The emulated protocol is called the host protocol. Observation-based FTE is a particular case of FTE that uses real observations from the host protocol for the transformation. By communicating using a shared dictionary according to the predefined protocol, it can difficult to detect anomalous traffic. Combining observation-based FTEs with hidden Markov models (HMMs) emulates every aspect of a host protocol. Ideal host protocols would cause significant collateral damage if blocked (protected) and do not contain dynamic handshakes or states (static). We use protected static protocols with the Protocol Proxy--a proxy that defines the syntax of a protocol using an observation-based FTE and transforms data to payloads with actual field values. The Protocol Proxy massages the outgoing packet\u27s interpacket delay to match the host protocol using an HMM. The HMM ensure the outgoing traffic is statistically equivalent to the host protocol. The Protocol Proxy is a covert channel, a method of communication with a low probability of detection (LPD). These covert channels trade-off throughput for LPD. The multipath TCP (mpTCP) Linux kernel module splits a TCP streams across multiple interfaces. Two potential architectures involve splitting a covert channel across several interfaces (multipath) or splitting a single TCP stream across multiple covert channels (multisession). Splitting a covert channel across multiple interfaces leads to higher throughput but is classified as mpTCP traffic. Splitting a TCP flow across multiple covert channels is not as performant as the previous case, but it provides added obfuscation and resiliency. Each covert channel is independent of the others, and a channel failure is recoverable. The multipath and multisession frameworks provide independently address the issues associated with covert channels. Each tool addresses a challenge. The Protocol Proxy provides anonymity in a setting were detection could have critical consequences. The mpTCP kernel module offers an architecture that increases throughput despite the channel\u27s low-bandwidth restrictions. Fusing these architectures improves the goodput of the Protocol Proxy without sacrificing the low probability of detection

Interventions to optimise the outputs of national clinical audits to improve the quality of health care: a multi-method study including RCT

Background National clinical audit programmes aim to improve patient care by reviewing performance against explicit standards and directing action towards areas not meeting those standards. Their impact can be improved by (1) optimising feedback content and format, (2) strengthening audit cycles and (3) embedding randomised trials evaluating different ways of delivering feedback. Objectives The objectives were to (1) develop and evaluate the effects of modifications to feedback on recipient responses, (2) identify ways of strengthening feedback cycles for two national audits and (3) explore opportunities, costs and benefits of national audit participation in a programme of trials. Design An online fractional factorial screening experiment (objective 1) and qualitative interviews (objectives 2 and 3). Setting and participants Participants were clinicians and managers involved in five national clinical audits – the National Comparative Audit of Blood Transfusions, the Paediatric Intensive Care Audit Network, the Myocardial Ischaemia National Audit Project, the Trauma Audit & Research Network and the National Diabetes Audit – (objective 1); and clinicians, members of the public and researchers (objectives 2 and 3). Interventions We selected and developed six online feedback modifications through three rounds of user testing. We randomised participants to one of 32 combinations of the following recommended specific actions: comparators reinforcing desired behaviour change; multimodal feedback; minimised extraneous cognitive load for feedback recipients; short, actionable messages followed by optional detail; and incorporating ‘the patient voice’ (objective 1). Main outcome measures The outcomes were intended actions, including enactment of audit standards (primary outcome), comprehension, user experience and engagement (objective 1). Results For objective 1, the primary analysis included 638 randomised participants, of whom 566 completed the outcome questionnaire. No modification independently increased intended enactment of audit standards. Minimised cognitive load improved comprehension (+0.1; p = 0.014) and plans to bring audit findings to colleagues’ attention (+0.13, on a –3 to +3 scale; p = 0.016). We observed important cumulative synergistic and antagonistic interactions between modifications, participant role and national audit. The analysis in objective 2 included 19 interviews assessing the Trauma Audit Research Network and the National Diabetes Audit. The identified ways of strengthening audit cycles included making performance data easier to understand and guiding action planning. The analysis in objective 3 identified four conditions for effective collaboration from 31 interviews: compromise – recognising capacity and constraints; logistics – enabling data sharing, audit quality and funding; leadership – engaging local stakeholders; and relationships – agreeing shared priorities and needs. The perceived benefits of collaboration outweighed the risks. Limitations The online experiment assessed intended enactment as a predictor of actual clinical behaviour. Interviews and surveys were subject to social desirability bias. Conclusions National audit impacts may be enhanced by strengthening all aspects of feedback cycles, particularly effective feedback, and considering how different ways of reinforcing feedback act together

Surgical rib fracture fixation : systematic review of effectiveness, assessment of current UK practice, and development of a core outcome set

AimTo synthesise contemporary evidence for rib fracture fixation, and thereby to fill the gaps in the knowledge required to inform a trial and provide recommendations for future study.MethodA systematic review of systematic reviews and a meta-analysis of primary research were the methods used to examine the effectiveness of rib fracture fixation. Delphi consensus methods were used to survey three international stakeholder groups so as to define a core outcome set and a consensus on indications for and timing of rib fracture fixation. A United Kingdom (UK) survey assessed the provision of rib fracture care and analysis of a UK trauma database assessed the factors that predict rib fixation and the outcomes experienced by rib fracture patients.ResultsThe systematic reviews and meta-analysis suggest that rib fracture fixation shortens the duration of mechanical ventilation, reduces critical care and hospital stay as well as overall mortality. UK clinical data suggests that rib fracture fixation improves these outcomes, and that early intervention confers an advantage over late fixation. With regard to which patients receive an intervention; fracture pattern, pulmonary contusion, admission to a major trauma centre, injury severity and age are all important predictors of undergoing surgery. A core outcome set was derived to include 23 outcomes. Consensus was achieved on 20 indications and 7 timings of surgery. Care of rib fracture patients in England and Wales is delivered in a variety of centres with different care protocols, referral pathways, lead specialties and rehabilitation services.ConclusionFurther evidence is required to assess the effectiveness of rib fracture fixation. A feasibility trial is required to understand more clearly if clinicians have equipoise, patients are willing to be randomised and whether comparative care can be delivered. A trial will need to be stratified for surgical indication and further study is required to define outcome instruments

East Lancashire Research 2008

East Lancashire Research 200

Open fractures of the tibia: a national, regional and individual perspective

Introduction Open tibial fractures are complex high energy injuries, associated with soft tissue loss and contamination; they are amongst the most severe injuries seen in orthopaedic practice. Modern practice demonstrates a tendency to reconstruct severely injured limbs; yet despite the use of aggressive protocols, recovery is often incomplete with long-term implications for patients. Robust research in this field is limited; much of the published work is based on single institutional experiences and hampered by poor study design. Ultimately, there will be a role for randomised controlled trials in determining the best interventions for these patients; although research questions in randomised controlled trials must be set on firm foundations with comprehensive work undertaken to understand current perspectives. These perspectives are currently not clearly outlined in the literature where; epidemiological patterns, the limits of established practice and patient views are all poorly represented. The aim of this thesis is to pursue answers to these questions, with an overall purpose of supporting the future development of high quality research in open tibial fractures. Methods A mixed-methods study with a sequential explanatory study design. Descriptive statistics, sensitivity analysis and generalised linear models were used to analyse data from two large datasets. The two datasets included data from the Trauma Audit Research Network (TARN); the national registry for trauma which contains comprehensive characterisation of patients and care-pathways; and a detailed local injury register from the East Midlands Trauma Centre which holds linked micro-costings and a cross-sectional patient-reported outcome measures (PROMS) dataset. A qualitative systematic review was performed using Joanna Briggs Institute methodology, and the results of these three studies were triangulated to inform the design of a qualitative study considering patient perspective. The qualitative study used semi-structured interviews with individuals who had sustained an open tibial fracture 12-72 months ago and were analysed using framework and cross-case analysis. Results Based on an analysis of 7994 cases from the TARN dataset, crude incidence rate of open tibial fracture was 2.85 per 100,000 persons per year. Injury occurred most frequently in males aged 25-30; however, incidence was 15% higher in patients aged over 65 when compared to the 15-39 age group (IRR: 1.15 (1.09-1.22). A fully adjusted model identified the mortality rate was two times greater in patients with comorbidities (OR: 2.34, CI: 1.60 – 3.42). In a further fully adjusted model including 2157 Gustilo 3B or 3C fractures, time to soft tissue coverage was related to wound complications. The proportion of individuals experiencing early inpatient wound complication increased by 0.3% per hour until definitive soft tissue cover (OR: 1.003, (CI: 1.001 - 1.004); other variables in this model relating to the injury or treatment were mostly not significant. The study highlighted the challenges of applying a research question to a dataset collected with a different aim. The regional injury dataset included 212 individuals. The complication rate was 24% with mean time to revision surgery at 260 days. One year after injury, individuals reported a 26% (p<0.01) reduction in quality of life, and a 30% increase in disability (p<0.01). The mean cost of treatment was £27312, however, there was significant variation in cost dependant on injuries, treatment (p<0.05) and complications (p<0.05). The qualitative study included 26 individuals who described recovery with parallel physical and psychological narratives. Regaining mobility was a priority for individuals who perceived this to be the gateway to returning to their former roles and responsibilities; whilst mobility was important, many symptoms were reported. The breakdown of routine and purpose that came after the accident was devastating and challenging to navigate. Hope was difficult to sustain due to unknown outcomes, although coping strategies such as goal setting and seeking personal support were important psychological mediators. Experience of recovery differed dependant on fixation strategy; with ring-fixators appearing more difficult to tolerate with broad social consequences. Age was also relevant; the gravity of these challenges was exacerbated for younger individuals, who did not have the financial stability or social capital to endure this life-changing injury without long-term social ramifications. Conclusion: This thesis provides a clear national picture of the epidemiology, care pathways and costs associated with open tibial fracture, and provides insight into the implications of this injury for individuals. The thesis offers a case for improving surgical care for individuals with an open tibial fracture; but recognises that this will only be achieved with carefully planned research that adequately controls for variation in these injuries. In addition, modest restructuring of care-pathways to acknowledge the psychosocial implications of these injuries could dramatically improve patient experience with minimal cost

The BG News October 25, 2002

The BGSU campus student newspaper October 25, 2002. Volume 91 - Issue 43https://scholarworks.bgsu.edu/bg-news/8021/thumbnail.jp

Open fractures of the tibia: a national, regional and individual perspective

Introduction Open tibial fractures are complex high energy injuries, associated with soft tissue loss and contamination; they are amongst the most severe injuries seen in orthopaedic practice. Modern practice demonstrates a tendency to reconstruct severely injured limbs; yet despite the use of aggressive protocols, recovery is often incomplete with long-term implications for patients. Robust research in this field is limited; much of the published work is based on single institutional experiences and hampered by poor study design. Ultimately, there will be a role for randomised controlled trials in determining the best interventions for these patients; although research questions in randomised controlled trials must be set on firm foundations with comprehensive work undertaken to understand current perspectives. These perspectives are currently not clearly outlined in the literature where; epidemiological patterns, the limits of established practice and patient views are all poorly represented. The aim of this thesis is to pursue answers to these questions, with an overall purpose of supporting the future development of high quality research in open tibial fractures. Methods A mixed-methods study with a sequential explanatory study design. Descriptive statistics, sensitivity analysis and generalised linear models were used to analyse data from two large datasets. The two datasets included data from the Trauma Audit Research Network (TARN); the national registry for trauma which contains comprehensive characterisation of patients and care-pathways; and a detailed local injury register from the East Midlands Trauma Centre which holds linked micro-costings and a cross-sectional patient-reported outcome measures (PROMS) dataset. A qualitative systematic review was performed using Joanna Briggs Institute methodology, and the results of these three studies were triangulated to inform the design of a qualitative study considering patient perspective. The qualitative study used semi-structured interviews with individuals who had sustained an open tibial fracture 12-72 months ago and were analysed using framework and cross-case analysis. Results Based on an analysis of 7994 cases from the TARN dataset, crude incidence rate of open tibial fracture was 2.85 per 100,000 persons per year. Injury occurred most frequently in males aged 25-30; however, incidence was 15% higher in patients aged over 65 when compared to the 15-39 age group (IRR: 1.15 (1.09-1.22). A fully adjusted model identified the mortality rate was two times greater in patients with comorbidities (OR: 2.34, CI: 1.60 – 3.42). In a further fully adjusted model including 2157 Gustilo 3B or 3C fractures, time to soft tissue coverage was related to wound complications. The proportion of individuals experiencing early inpatient wound complication increased by 0.3% per hour until definitive soft tissue cover (OR: 1.003, (CI: 1.001 - 1.004); other variables in this model relating to the injury or treatment were mostly not significant. The study highlighted the challenges of applying a research question to a dataset collected with a different aim. The regional injury dataset included 212 individuals. The complication rate was 24% with mean time to revision surgery at 260 days. One year after injury, individuals reported a 26% (p<0.01) reduction in quality of life, and a 30% increase in disability (p<0.01). The mean cost of treatment was £27312, however, there was significant variation in cost dependant on injuries, treatment (p<0.05) and complications (p<0.05). The qualitative study included 26 individuals who described recovery with parallel physical and psychological narratives. Regaining mobility was a priority for individuals who perceived this to be the gateway to returning to their former roles and responsibilities; whilst mobility was important, many symptoms were reported. The breakdown of routine and purpose that came after the accident was devastating and challenging to navigate. Hope was difficult to sustain due to unknown outcomes, although coping strategies such as goal setting and seeking personal support were important psychological mediators. Experience of recovery differed dependant on fixation strategy; with ring-fixators appearing more difficult to tolerate with broad social consequences. Age was also relevant; the gravity of these challenges was exacerbated for younger individuals, who did not have the financial stability or social capital to endure this life-changing injury without long-term social ramifications. Conclusion: This thesis provides a clear national picture of the epidemiology, care pathways and costs associated with open tibial fracture, and provides insight into the implications of this injury for individuals. The thesis offers a case for improving surgical care for individuals with an open tibial fracture; but recognises that this will only be achieved with carefully planned research that adequately controls for variation in these injuries. In addition, modest restructuring of care-pathways to acknowledge the psychosocial implications of these injuries could dramatically improve patient experience with minimal cost