Piecewise Affine Dynamical Models of Petri Nets – Application to Emergency Call Centers*

We study timed Petri nets, with preselection and priority routing. We represent the behavior of these systems by piecewise affine dynamical systems. We use tools from the theory of nonexpansive mappings to analyze these systems. We establish an equivalence theorem between priority-free fluid timed Petri nets and semi-Markov decision processes, from which we derive the convergence to a periodic regime and the polynomial-time computability of the throughput. More generally, we develop an approach inspired by tropical geometry, characterizing the congestion phases as the cells of a polyhedral complex. We illustrate these results by a current application to the performance evaluation of emergency call centers in the Paris area. We show that priorities can lead to a paradoxical behavior: in certain regimes, the throughput of the most prioritary task may not be an increasing function of the resources.

Significance of Pelvic Fluid Observed during Ovarian Cancer Screening with Transvaginal Sonogram

The primary objective was to examine the role of pelvic fluid observed during transvaginal ultrasonography (TVS) in identifying ovarian malignancy. A single-institution, observational study was conducted within the University of Kentucky Ovarian Cancer Screening trial from January 1987 to September 2019. We analyzed true-positive (TP), false-positive (FP), true-negative (TN), and false-negative (FN) groups for the presence of pelvic fluid during screening encounters. Measured outcomes were the presence and duration of fluid over successive screening encounters. Of the 48,925 women surveyed, 2001 (4.1%) had pelvic fluid present during a TVS exam. The odds ratio (OR) of detecting fluid in the comparison group (TN screen; OR = 1) significantly differed from that of the FP cases (benign pathology; OR: 13.4; 95% confidence interval (CI): 9.1–19.8), the TP cases with a low malignant potential (LMP; OR: 28; 95% CI: 26.5–29.5), TP ovarian cancer cases (OR: 50.4; 95% CI: 27.2–93.2), and FN ovarian cancer cases (OR: 59.3; 95% CI: 19.7–178.1). The mean duration that pelvic fluid was present for women with TN screens was 2.2 ± 0.05 encounters, lasting 38.7 ± 1.3 months. In an asymptomatic screening population, free fluid identified in TVS exams was more associated with ovarian malignancy than in the control group or benign ovarian tumors. While pelvic free fluid may not solely discriminate malignancy from non-malignancy, it appears to be clinically relevant and warrants thoughtful consideration.

Uterine Rupture of a Patient With Rudimentary Horn Pregnancy at 26th Gestational Weeks Diagnosed via Magnetic Resonance Imaging: a Case Report

Objective: Pregnancy of Rudimentary Horn is a type of ectopic pregnancy, that is recognized almost always during surgical treatment of a rupture of the rudimentary horn. This is an obstetric case diagnosed preoperatively by magnetic resonance imaging (MRI).Case: We report the case of a 19-years-old primigravida patient with rupture of rudimentary horn in 26th gestational week. The patient presented with sudden onset severe abdominal pain in the emergency room. Intraabdominal free fluid is detected. To evaluate the etiology of free fluid and location of the gestational sac, an abdominal magnetic resonance imaging (MRI) scan was planned. The decision of emergent laparotomy is made because of sonographic detection of abdominal excessive -concentrated- free fluid, abdominal tenderness, and 2 points decrease of hemoglobin value in the control hemogram. A rudimentary horn pregnancy and fundal rupture of the rudimentary part of the uterus are diagnosed during the surgical procedure. A baby -live- weighing 450 grams was delivered. The ruptured rudimentary horn and same-sided tuba uterina were surgically removed.Conclusion: Rudimentary horn pregnancy is a rare ectopic pregnancy. Diagnosis is difficult clinically, even with diagnostic imaging modalities. Identifying both cornuas systematically in all patients increases the detection rate. The absence of continuity between the gestational sac’s lumen and the cervical canal on imaging is an important finding. Due to the serious maternal and fetal complications, its detection at an early week may be life-saving.

Giant Fibrothecoma of the Ovary in a Young Patient a Case Report

Fibrothecomas are benign ovarian stromal tumors, they are rare tumors of gonadal stromal cell origin that represent 3-4% of all ovarian tumors. It commonly occurs in post-menopausal women. The clinical presentation is often nonspecific, whereas patients more frequently present with a pelvic mass, metrorrhagia, and pelvic pain. We present a 35-year-old patient, nulli-pregnant, with no personal or family pathological history, who attended a medical consultation for presenting progressive abdominal distention of 6 months of evolution in addition to abdominal pain in the last 2 months type colic which increased during her menstrual periods concomitantly alteration in your defecatory habits. Abdominal ultrasound was performed, finding a solid intrapelvic mass of approximately 14x10x10 cm in diameter of probable left ovarian origin, free fluid in the Douglas space, compression and displacement of intestinal loops and bladder. The patient underwent surgery and an exploratory laparotomy was performed, finding a pelvic tumor adhered to the tube and left ovary, in addition to ascites fluid in the abdominal cavity, complete resection of the tumor, ovary and left salpingue was performed.

A Curious “Appendicitis”, Magnetic Foreign Bodies Ingestion In a Five Year Old Girl With Ileal Perforation. Case Report and Review of Literature.

BackgroundForeign body ingestion is common in children. Ingestion of multiple magnetic foreign bodies poses a significant risk of complications as they are unlikely to pass spontaneously. Case presentationWe present our interesting case of a 5 Year old girl, complaining of right iliac fossa pain not relieved with paracetamol, associated with 2 episodes of vomiting and one episode of loose bowel motion. Abdominal examination revealed tender right iliac fossa with weak rebound and mild guarding with no rigidity. WBC was 16.9, with 12.68 neutrophils, with normal urea, creatinine, amylase, CRP and liver function tests. Patient was admitted for suspected appendicitis versus gastroenteritis. Abdominal ultrasound showed free fluid in the pelvis, appendix was not seen and there was a mass in the right iliac fossa. The patient was started on intravenous co-amoxiclav and diagnostic laparoscopy revealed a normal appendix with free fluid in pelvis. The omentum was stuck to terminal ileum with two necrotic patches and a perforation in the terminal ileum with magnetic foreign bodies protruding from the perforation site.There was no peritoneal contamination. Laparotomy was performed via right lower transverse incision with resection & anastomosis of necrotic perforated bowel segment and removal of three magnetic foreign bodies from the terminal ileum. Patient had smooth postoperative recovery. ConclusionThe Ingestion of multiple magnets, or a magnet with a metallic object should be considered an impending surgical emergency as it is unlikely to pass spontaneously and complications are more likely. There are no reports where more than one magnet was passed spontaneously. The possibility of foreign body ingestion should always be considered in a young child presenting with abdominal symptoms. Early intervention is indicated if the history, clinical findings and imaging are suggestive of multiple magnetic ingestion to prevent serious life threatening complications.

Can I Be Pregnant? – Diagnostic Challenges in Ruptured Chronic Ectopic Pregnancy

Ectopic pregnancy is an obstetric emergency which accounts for 4% of all pregnancy-related deaths. All women of child bearing age with abdominal pain or vaginal bleeding presenting to the Emergency Department should be evaluated for ectopic pregnancy. However, there have been many reported cases of diagnostic challenges of ectopic pregnancy. One rare variant of ectopic pregnancy that can be easily overlooked is chronic ectopic pregnancy. We present this case of a 39-yearold female, who presented with acute abdomen and free fluid in her abdomen. Urine pregnancy test indicated she was not pregnant. However, intraoperative findings confirmed left tubular pregnancy. We would like to highlight three major diagnostic challenges we faced in this case i.e.; (i) women of child bearing age with abdominal pain should always be evaluated for ectopic pregnancy; (ii) diagnosis of ectopic pregnancy should not be dismissed even though the pregnancy test is negative; and (iii) the role of computed tomography (CT) scan in acute abdomen of unclear aetiology. As a rule, all haemodynamically unstable acute abdomen should be sent to the operation theatre. Haemodynamically stable patients should be carefully evaluated to facilitate surgical management.

Traumatic Small Bowel Injury: A Diagnosis Challenge

Traumatic small bowel injury is rare complication following a blunt abdominal trauma. We encountered a case of small bowel injury following a motor vehicle accident that was initially missed during the first presentation due to unremarkable findings in examination. Patient re-presented five days later with bowel ischaemia and was managed accordingly. It is a challenge in diagnosing the injury due to its vague presentation. The usage of Focused Assessment with Sonography for Trauma (FAST) scan as a screening tool in Emergency Department to pick up intra-abdominal injury do have limitations especially in diagnosing small bowel perforation post blunt abdominal trauma. The early phase of small bowel injury post blunt abdominal trauma rarely produces significant free fluid during the FAST scan. It is paramount for the emergency doctors to have a high level of suspicion in high risk cases to provide early supportive treatment and early referral to surgical team. If left undiagnosed bowel ischaemia may lead to catastrophic complication affecting the patient’s morbidity and mortality. In conclusion, each case should be managed and risk stratify individually. Computed tomography abdomen is found to be more superior in detecting bowel injuries, hence, and investigation of choice compared to bedside ultrasonograpy in cases with high level of suspicaion.

Role of f(G) Gravity in the Study of Non-Static Complex Systems

The concept of complexity for dynamical spherically symmetric dissipative self-gravitating configuration [1] is generalized in the scenario of modified Gauss-Bonnet gravity. For this purpose, a spherically symmetric fluid with locally anisotropic, dissipative, and non-dissipative configuration is considered. We choose the same complexity factor for the structure as we did for the static case, while we consider the homologous condition for the simplest pattern of evolution. In this approach, we formulate structure scalars that demonstrate the essential properties of the system. A fluid distribution that fulfills the vanishing complexity constraint and proceeds homologously corresponds to isotropic, geodesic, homogeneous, and shear-free fluid. In the dissipative case, the fluid is still geodesic but it is shearing, and there is a wide range of solutions. In the last, the stability of vanishing complexity is examined.

USING NEURAL NETWORK MODELING TO PREDICT THE COURSE OF ACUTE PANCREATITIS

The database of studies of 82 patients with acute pancreatitis are presented. Using neural network analysis, the most indicative parameters for predicting acute pancreatitis were revealed: indexes of Kalf-Kalif intoxication modified by Kostyuchenko and Khomich, Reis, Garkavi, the ratio of leukocytes to ESR, leukocyte index, general intoxication index; sonographic parameters – the size of the head of the pancreas, the diameter of the splenic vein, the presence of free fluid in the abdominal cavity; biochemical parameters – blood amylase concentration, urine diastase. When conducting clustering in a multidimensional feature space, a Kohonen neural network was created. All analyzed objects were effectively divided into 3 clusters. The most severe and prognostically unfavorable is cluster 1, which included data from 30 patients, with the maximum mortality rate and maximum hospital stay.

A mixed elasticity formulation for fluid-poroelastic structure interaction

We develop a mixed finite element method for the coupled problem arising in the interaction between a free fluid governed by the Stokes equations and flow in deformable porous medium modeled by the Biot system of poroelasticity. Mass conservation, balance of stress, and the Beavers-Joseph-Saffman condition are imposed on the interface. We consider a fully mixed Biot formulation based on a weakly symmetric stress-displacement-rotation elasticity system and Darcy velocity-pressure flow formulation. A velocity-pressure formulation is used for the Stokes equations. The interface conditions are incorporated through the introduction of the traces of the structure velocity and the Darcy pressure as Lagrange multipliers. Existence and uniqueness of a solution are established for the continuous weak formulation. Stability and error estimates are derived for the semi-discrete continuous-in-time mixed finite element approximation. Numerical experiments are presented to verify the theoretical results and illustrate the robustness of the method with respect to the physical parameters.