175 research outputs found
Finite Automata for the Sub- and Superword Closure of CFLs: Descriptional and Computational Complexity
We answer two open questions by (Gruber, Holzer, Kutrib, 2009) on the
state-complexity of representing sub- or superword closures of context-free
grammars (CFGs): (1) We prove a (tight) upper bound of on
the size of nondeterministic finite automata (NFAs) representing the subword
closure of a CFG of size . (2) We present a family of CFGs for which the
minimal deterministic finite automata representing their subword closure
matches the upper-bound of following from (1).
Furthermore, we prove that the inequivalence problem for NFAs representing sub-
or superword-closed languages is only NP-complete as opposed to PSPACE-complete
for general NFAs. Finally, we extend our results into an approximation method
to attack inequivalence problems for CFGs
Peritonitis secondary to traumatic duodenal laceration in the presence of a large pancreatic pseudocyst: a case report
<p>Abstract</p> <p>Introduction</p> <p>A pancreatic pseudocyst is a common sequela of severe acute pancreatitis. Commonly, it presents with abdominal pain and a mass in the epigastrium several weeks after the acute episode and can be managed conservatively, endoscopically or surgically. We report a patient with a pancreatic pseudocyst awaiting endoscopic therapy who developed a life-threatening complication following a rather innocuous trauma to the abdomen.</p> <p>Case presentation</p> <p>A 23-year-old Asian male student presented as an emergency with an acute abdomen a week after a minor trauma to his upper abdomen. The injury occurred when he was innocently punched in the abdomen by a friend. He experienced only moderate discomfort briefly at the time. His past medical history included coeliac disease and an admission four months previously with severe acute pancreatitis. He was hospitalized for 15 days; his pancreatitis was thought to be due to alcohol binge drinking on weekends. Ultrasound scanning showed no evidence of gallstone disease. Five days after the trauma, he became anorexic, lethargic and feverish and started vomiting bilious content. Seven days post-trauma, he presented to our emergency department with severe abdominal pain. An emergency laparotomy was performed where a transverse linear duodenal laceration was found at the junction of the first and second part of his duodenum, with generalized peritonitis. His stomach and duodenum were stretched over a large pancreatic pseudocyst posterior to his stomach. It was postulated that an incomplete duodenal injury (possibly a serosal tear) occurred following the initial minor trauma, which was followed by local tissue necrosis at the injury site resulting in a delayed presentation of generalized peritonitis.</p> <p>Conclusion</p> <p>This is the first reported case of a traumatic duodenal laceration following minor blunt trauma in the presence of a large pancreatic pseudocyst. Minor blunt abdominal trauma in a normal healthy adult would not be expected to result in a significant duodenal injury. In the presence of a large pseudocyst, however, the stretching of the duodenum over the pseudocyst had probably predisposed the duodenum to this injury. Patients awaiting therapeutic interventions for their pancreatic pseudocysts should be warned about this unusual but life-threatening risk following minor blunt abdominal trauma.</p
Species-specific responses of planktivorous fish to the introduction of a new piscivore: implications for prey fitness
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75539/1/j.1365-2427.2007.01810.x.pd
The impact of age on predictive performance of national early warning score at arrival to emergency departments: development and external validation
Study objective: To investigate how age affects the predictive performance of the National Early Warning Score (NEWS) at arrival to the emergency department (ED) regarding inhospital mortality and intensive care admission.Methods: International multicenter retrospective cohorts from 2 Danish and 3 Dutch ED. Development cohort: 14,809 Danish patients aged >= 18 years with at least systolic blood pressure or pulse measured from the Danish Multicenter Cohort. External validation cohort: 50,448 Dutch patients aged >18 years with all vital signs measured from the Netherlands Emergency Department Evaluation Database (NEED). Multivariable logistic regression was used for model building. Performance was evaluated overall and within age categories: 18 to 64 years, 65 to 80 years, and more than 80 years.Results: In the Danish Multicenter Cohort, a total of 2.5% died inhospital, and 2.8% were admitted to the ICU, compared with 2.8% and 1.6%, respectively, in the NEED. Age did not add information for the prediction of intensive care admission but was the strongest predictor for inhospital mortality. For NEWS alone, severe underestimation of risk was observed for persons above 80 while overall Area Under Receiver Operating Characteristic (AUROC) was 0.82 (confidence interval [CI] 0.80 to 0.84) in the Danish Multicenter Cohort versus 0.75 (CI 0.75 to 0.77) in the NEED. When combining NEWS with age, underestimation of risks was eliminated for persons above 80, and overall AUROC increased significantly to 0.86 (CI 0.85 to 0.88) in the Danish Multicenter Cohort versus 0.82 (CI 0.81 to 0.83) in the NEED.Conclusion: Combining NEWS with age improved the prediction performance regarding inhospital mortality, mostly for persons aged above 80, and can potentially improve decision policies at arrival to EDs
EFSUMB Guidelines on Interventional Ultrasound (INVUS), Part II : Diagnostic ultrasound-guided interventional procedures (Long Version)
Publisher Copyright: © Georg Thieme Verlag KG Stuttgart New York.This is the second part of the series on interventional ultrasound guidelines of the Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB). It deals with the diagnostic interventional procedure. General points are discussed which are pertinent to all patients, followed by organ-specific imaging that will allow the correct pathway and planning for the interventional procedure. This will allow for the appropriate imaging workup for each individual interventional procedure (Long version).publishersversionPeer reviewe
The association between systolic blood pressure and heart rate in emergency department patients: a multicenter cohort study
BackgroundGuidelines and textbooks assert that tachycardia is an early and reliable sign of hypotension, and an increased heart rate (HR) is believed to be an early warning sign for the development of shock, although this response may change by aging, pain, and stress.ObjectiveTo assess the unadjusted and adjusted associations between systolic blood pressure (SBP) and HR in emergency department (ED) patients of different age categories (18–50 years; 50–80 years; > 80 years).MethodsA multicenter cohort study using the Netherlands Emergency department Evaluation Database (NEED) including all ED patients ≥ 18 years from three hospitals in whom HR and SBP were registered at arrival to the ED. Findings were validated in a Danish cohort including ED patients. In addition, a separate cohort was used including ED patients with a suspected infection who were hospitalized from whom measurement of SBP and HR were available prior to, during, and after ED treatment. Associations between SBP and HR were visualized and quantified with scatterplots and regression coefficients (95% confidence interval [CI]).ResultsA total of 81,750 ED patients were included from the NEED, and a total of 2358 patients with a suspected infection. No associations were found between SBP and HR in any age category (18–50 years: −0.03 beats/min/10 mm Hg, 95% CI −0.13–0.07, 51–80 years: −0.43 beats/min/10 mm Hg, 95% CI −0.38 to −0.50, > 80 years: −0.61 beats/min/10 mm Hg, 95% CI −0.53 to −0.71), nor in different subgroups of ED patient. No increase in HR existed with a decreasing SBP during ED treatment in ED patients with a suspected infection.ConclusionNo association between SBP and HR existed in ED patients of any age category, nor in ED patients who were hospitalized with a suspected infection, even during and after ED treatment. Emergency physicians may be misled by traditional concepts about HR disturbances because tachycardia may be absent in hypotension.Development and application of statistical models for medical scientific researc
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