Obesity is associated with poor surgical outcome in Crohn\u27s disease

BACKGROUND: Published data suggest a link between obesity and adverse outcomes in Crohn\u27s disease (CD). We aimed to test the hypothesis that obese CD patients would be more likely than non-obese CD patients to have poor surgical outcome when undergoing surgery for a complication of CD. METHODS: We designed a retrospective cohort study to test our hypothesis. The population comprised of adult CD patients who underwent CD related surgery at a tertiary referral center. The exposed and unexposed cohorts were represented by patients who were obese vs. non-obese at the pre-op visit respectively. Outcome was represented by successful vs. unsuccessful surgical outcome as deemed by the treating clinician. RESULTS: Ninety CD patients were eligible for inclusion into this cohort study of which 36 were obese (exposed cohort) and 54 were non-obese (unexposed cohort). Among obese CD patients, 64% had an unsuccessful surgical outcome vs. 41% with unsuccessful surgical outcome among the non-obese. Based on unadjusted bivariate analysis, potential confounders identified included age and type of surgery. Gender distribution, disease duration, ethnicity, tobacco use, steroid use, traditional and biological immune modulator use and clinical disease activity were similar between the two groups. Logistic regression adjusted for age and type of surgery revealed that obese CD patients were approximately 2.5 times more likely to have a poor surgical outcome than patients with CD who were not obese (P = 0.05 OR 2.53 95% CI 0.99 - 6.52). BMI as a continuous variable (adjusted for age and type of surgery) appeared to be associated with poor surgical outcome (P = 0.06 OR 1.07 95% CI 0.99 - 1.15). CONCLUSIONS: Obesity may be associated with poor surgical outcome in CD patients

Security Verification of Low-Trust Architectures

Low-trust architectures work on, from the viewpoint of software, always-encrypted data, and significantly reduce the amount of hardware trust to a small software-free enclave component. In this paper, we perform a complete formal verification of a specific low-trust architecture, the Sequestered Encryption (SE) architecture, to show that the design is secure against direct data disclosures and digital side channels for all possible programs. We first define the security requirements of the ISA of SE low-trust architecture. Looking upwards, this ISA serves as an abstraction of the hardware for the software, and is used to show how any program comprising these instructions cannot leak information, including through digital side channels. Looking downwards this ISA is a specification for the hardware, and is used to define the proof obligations for any RTL implementation arising from the ISA-level security requirements. These cover both functional and digital side-channel leakage. Next, we show how these proof obligations can be successfully discharged using commercial formal verification tools. We demonstrate the efficacy of our RTL security verification technique for seven different correct and buggy implementations of the SE architecture.Comment: 19 pages with appendi

Navigating to Objects Specified by Images

Images are a convenient way to specify which particular object instance an embodied agent should navigate to. Solving this task requires semantic visual reasoning and exploration of unknown environments. We present a system that can perform this task in both simulation and the real world. Our modular method solves sub-tasks of exploration, goal instance re-identification, goal localization, and local navigation. We re-identify the goal instance in egocentric vision using feature-matching and localize the goal instance by projecting matched features to a map. Each sub-task is solved using off-the-shelf components requiring zero fine-tuning. On the HM3D InstanceImageNav benchmark, this system outperforms a baseline end-to-end RL policy 7x and a state-of-the-art ImageNav model 2.3x (56% vs 25% success). We deploy this system to a mobile robot platform and demonstrate effective real-world performance, achieving an 88% success rate across a home and an office environment