49 research outputs found

    Optimal dynamic auditing based on game theory

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    A dynamic model based on game-theory is proposed to address the problem of fraud detection in auditing under non-linear payoff functions. Non-linearity is introduced by incorporating learning and sympathy effects in the audit process. It is proven that the audit/fraud detection game between two new engagement parties has a unique mixed strategy equilibrium, between an experienced auditor and a client has a unique pure strategy equilibrium, whereas in the long-run the game converges to a pure strategy equilibrium. In addition to this, to ensure an acceptable level of quality in the audit process, a closed form formula used to estimate the optimal auditor’s replacement time is extracted. The validity of the proposed scheme is tested on empirical data and modeling results comply with the International Standard of Auditing that requires the key audit partner to be rotated after a predefined period

    System Identification of Tunnel Response to Ground Motion Considering a Simplified Model

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    This paper presents a simplified model using coupled Bernoulli and shear beams supported by Winkler-type springs for system identification of tunnels subjected to earthquake induced ground motions. The model formulation is introduced and closed-form solutions to the modal characteristic equation and mode shapes are derived. The latter are verified against the results of numerical models. Then, the system identification algorithm is presented, showcasing its ability to recover model parameters when recorded acceleration time histories along the tunnel are compromised by noise and sensor locations are varied. The presented framework can be used to initially and, simply, recover tunnel response when monitoring data is available, or to plan for monitoring campaigns in newly constructed or existing tunnels

    Fulminant Aeromonas hydrophila infection during acute lymphoblastic leukemia treatment

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    Aeromonas hydrophila septicemia has a fulminant course and it has been usually reported in immunocompromised hosts and rarely among children with leukemia. High morbidity and mortality is associated with A hydrophila infections. We describe the case of a child with acute lymphoblastic leukemia who presented with septicemia due to A hydrophila. The patient presented with fever and skin discoloration during a febrile neutropenia episode, which rapidly evolved into bacteremia and extensive thigh suppuration, fasciitis, and myonecrosis. Apart from antibiotic treatment, surgical debridement to relieve compartment pressure and prevent further lower extremity compromise was promptly performed. Despite long delays in chemotherapy and an extensive tissue gap, primary closure of the involved area was possible with full cosmetic and functional limb recovery, and the patient has remained in clinical remission for more than 7 years

    Factors Associated With Retinal Vessel Diameters in an Elderly Population: the Thessaloniki Eye Study

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    Purpose: To identify the factors associated with retinal vessel diameters in the population of the Thessaloniki Eye Study. Methods: Cross-sectional population-based study (age ≥ 60 years). Subjects with glaucoma, late age-related macular degeneration, and diabetic retinopathy were excluded from the analyses. Retinal vessel diameters were measured using the IVAN software, and measurements were summarized to central retinal artery equivalent (CRAE), central retinal vein equivalent (CRVE), and arteriole to venule ratio (AVR). Results: The analysis included 1614 subjects. The hypertensive group showed lower values of CRAE (P = 0.033) and AVR (P = 0.0351) compared to the normal blood pressure (BP) group. On the contrary, the group having normal BP under antihypertensive treatment did not have different values compared to the normal BP group. Diastolic BP (per mm Hg) was negatively associated with CRAE (P < 0.0001) and AVR (P < 0.0001), while systolic BP (per mm Hg) was positively associated with CRAE (P = 0.001) and AVR (P = 0.0096). Other factors significantly associated included age, sex, alcohol, smoking, cardiovascular disease history, ophthalmic medication, weight, and IOP; differences were observed in a stratified analysis based on BP medication use. Conclusions: Our study confirms previous reports about the association of age and BP with vessel diameters. The negative correlation between BP and CRAE seems to be guided by the effect of diastolic BP as higher systolic BP is independently associated with higher values of CRAE. The association of BP status with retinal vessel diameters is determined by diastolic BP status in our population. Multiple other factors are also independently associated with retinal vessel diameters

    Safety and effectiveness of outpatient laparoscopic cholecystectomy in a teaching hospital: a prospective study of 110 consecutive patients

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    <p>Abstract</p> <p>Background</p> <p>The aim of this study was to evaluate the safety and efficacy of outpatient laparoscopic cholecystectomy (OLC) in a day surgery unit in a teaching hospital. OLC was offered to patients with symptomatic cholelithiasis who met the following established inclusion criteria: ASA (American Society of Anesthesiology) physical status classification class I and II; age: 18 - 70 years; body mass index (BMI) < 30 kg/m<sup>2</sup>; patient acceptance and cooperation (informed consent); presence of a responsible adult to accompany the patient to his residency; patient residency in Athens. The primary study end-point was to evaluate success rates (patient discharge on the day of surgery), postoperative outcome (complications, re-admissions, morbidity and mortality) and patient satisfaction. A secondary endpoint was to evaluate its safe performance under appropriate supervision by higher surgical trainees (HSTs).</p> <p>Findings</p> <p>110 consecutive patients, predominantly female (71%) and ASA I (89%) with a mean age 40.6 ± 8.1 years underwent an OLC. Surgery was performed by a HST in 90 patients (81.8%). A mean postoperative pain score 3.3 (range 0-6) occurred in the majority of patients and no patient presented postoperative nausea or vomiting. Discharge on the day of surgery occurred in 95 cases (86%), while an overnight admission was required for 15 patients (14%). Re-admission following hospital discharge was necessary for 2 patients (1.8%) on day 2, due to persistent pain in the umbilical trocar site. The overall rate of major (trocar site bleeding) and minor morbidity was 15.5% (17 patients). At 1 week follow-up, 94 patients (85%) were satisfied with their experience undergoing OLC, with no difference between grades of operating surgeons.</p> <p>Conclusions</p> <p>This study confirmed that OLC is clinical effective and can be performed safely in a teaching hospital by supervised HSTs.</p

    Esophagopericardial fistula as a rare complication after total gastrectomy for cancer

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    <p>Abstract</p> <p>Background</p> <p>Esophagopericardial fistula is a rare but life-threatening complication of benign, malignant or traumatic esophageal disease. It is most commonly associated with benign etiology and carries a high mortality rate which increases with delay in diagnosis.</p> <p>Case presentation</p> <p>We present a case of an esophagopericardial fistula as a rare complication in a 53-year-old male patient, 7 months after total gastrectomy for an adenocarcinoma of the esophagogastric junction.</p> <p>Conclusion</p> <p>The prognosis of esophagopericardial fistula is poor, especially when it is associated with malignancy.</p

    Humeral septal aperture associated with supracondylar process: a case report and review of the literature

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    The supracondylar process is usually a beak-like osseous prominence located at the anteromedial aspect of the distal portion of the humerus. It is usually asymptomatic but occasionally may compress underlying structures such as the median or ulnar nerve, the brachial artery or its branches. The term septal aperture defines an oval or round shaped bony defect of the septum that separates the olecranon from the coronoid fossa of the humerus. It is of significance for surgeons because it may alter the fracture pattern at the region and thus their management. We present a rare case of coexistence of supracondylar process and septal aperture in a macerated left humerus. The reported incidence of the supracondylar process alone varies from 0.28% to 2.78%, while that of the septal aperture from 6.9% to 60%. We have reviewed the literature and emphasized the radiological and surgical significance of the findings
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