Renforcement de systèmes de détection d’intrusions par des attaques GAN et métaheuristiques

Un système de détection d’intrusion est un outil capital en cybersécurité. Il sert aux administrateurs réseau d’identifier le traffic internet malicieux, et les cyberattaques : une fois celle-ci détectée, l’administrateur prend des décisions afin d’arrêter l’attaque en cours. Grâce au développement de l’Intelligence artificielle, de plus en plus de système de détection d’intrusion sont basés sur des algorithmes d’apprentissage automatique. Ces algorithmes ont en effet la particularité d’être capable de traiter des données rapidement une fois entraînés, ce qui est un facteur important dans le cadre de la détection d’attaques. Ces algorithmes de détection se basent sur des métriques issues du réseau, comme le débit entrant par seconde, le port de destination, ... Des ensembles de données des métriques lors de différents types d’attaques informatiques existent, et c’est sur l’un d’eux que nous nous baserons pour notre étude. Néanmoins, diverses études ont montré que ces algorithmes sont peu robustes lorsque confrontés à des types d’attaques nouveaux. Considérant le nombre croissant de nouvelles attaques informatiques ainsi que la possibilité de générer des attaques grâce à des algorithmes d'apprentissage, disposer d’un outil de détection capable de déceler ces attaques inhabituelles devient une nécessité. Ce travail explore la possibilité d’utiliser des modèles génératifs dans le but de rendre des systèmes de détection basés sur des algorithmes d’intelligence artificielle plus robuste. Nous avons développé la méthode SIGMA, utilisant des Generative Adversarial Networks (GANs) et des métaheuristiques afin de confronter des IDS à de nouveaux types d’attaques. L’usage de ces deux méthodes permet en effet d’explorer un espace de solutions trop grand pour effectuer des méthodes de résolution exactes. SIGMA génère des exemples d’attaques, itérativement, et les utilise pour réentraîner le système de détection jusqu’à convergence, c’est à dire jusqu’à ce qu’il ne soit plus possible d’améliorer l’IDS.----------ABSTRACT: An Intrusion Detection System (IDS) is a key cybersecurity tool for network administrators as it identifies malicious traffic and cyberattacks. With the recent successes of machine learning techniques such as deep learning, more and more IDS are now using machine learning algorithms to detect attacks faster. However, these systems lack robustness when facing previously unseen types of attacks. With the increasing number of new attacks, especially against Internet of Things devices, having a robust IDS able to spot unusual and new attacks becomes necessary. Those algorithms are trained with data from the network, such as the destination port, the incoming data rate, ... Datasets of network data during cyberattack are accessible, and we’ll be using a recent dataset for our study. This work explores the possibility of leveraging generative adversarial models to improve the robustness of machine learning based IDS. More specifically, we propose a new method named SIGMA, that leverages adversarial examples to strengthen IDS against new types of attacks. Using Generative Adversarial Networks (GAN) and metaheuristics, SIGMA generates adversarial examples, iteratively, and uses it to retrain a machine learning-based IDS, until a convergence of the detection rate (i.e. until the detection system is not improving anymore). Using metaheuristics and GANs allow to efficiently explore the solution space of a problem too complex to use exhaustive search methods. A round of improvement consists of a generative phase, in which we use GANs and metaheuristics to generate instances ; an evaluation phase in which we calculate the detection rate of those newly generated attacks ; and a training phase, in which we train the IDS with those attacks

Is Palliative Laparoscopic Hyperthermic Intraperitoneal Chemotherapy Effective in Patients with Malignant Hemorrhagic Ascites?

Malignant hemorrhagic ascites may complicate the terminal evolution of digestive cancers with peritoneal carcinomatosis. It has a bad influence on prognosis and may severely impair patients’ quality of life. Palliative laparoscopic hyperthermic intraperitoneal chemotherapy (HIPEC) has been proposed to treat debilitating malignant ascites. Two cases of peritoneal carcinomatosis causing hemorrhagic ascites and severe anemia that needed iterative blood transfusions are reported. These patients were treated by laparoscopic HIPEC (mitomycin C and cisplatin with an inflow temperature of 43°C), resulting in cessation of peritoneal bleeding. No postoperative complication or relapse of ascites occurred during the following months. No more blood transfusion was needed. Laparoscopic HIPEC might be an effective and safe therapeutic option to consider in patients with malignant hemorrhagic ascites

Open versus laparoscopically-assisted oesophagectomy for cancer: a multicentre randomised controlled phase III trial - the MIRO trial

<p>Abstract</p> <p>Background</p> <p>Open transthoracic oesophagectomy is the standard treatment for infracarinal resectable oesophageal carcinomas, although it is associated with high mortality and morbidity rates of 2 to 10% and 30 to 50%, respectively, for both the abdominal and thoracic approaches. The worldwide popularity of laparoscopic techniques is based on promising results, including lower postoperative morbidity rates, which are related to the reduced postoperative trauma. We hypothesise that the laparoscopic abdominal approach (laparoscopic gastric mobilisation) in oesophageal cancer surgery will decrease the major postoperative complication rate due to the reduced surgical trauma.</p> <p>Methods/Design</p> <p>The MIRO trial is an open, controlled, prospective, randomised multicentre phase III trial. Patients in study arm A will receive laparoscopic-assisted oesophagectomy, i.e., a transthoracic oesophagectomy with two-field lymphadenectomy and laparoscopic gastric mobilisation. Patients in study arm B will receive the same procedure, but with the conventional open abdominal approach. The primary objective of the study is to evaluate the major postoperative 30-day morbidity. Secondary objectives are to assess the overall 30-day morbidity, 30-day mortality, 30-day pulmonary morbidity, disease-free survival, overall survival as well as quality of life and to perform medico-economic analysis. A total of 200 patients will be enrolled, and two safety analyses will be performed using 25 and 50 patients included in arm A.</p> <p>Discussion</p> <p>Postoperative morbidity remains high after oesophageal cancer surgery, especially due to major pulmonary complications, which are responsible for 50% of the postoperative deaths. This study represents the first randomised controlled phase III trial to evaluate the benefits of the minimally invasive approach with respect to the postoperative course and oncological outcomes in oesophageal cancer surgery.</p> <p>Trial Registration</p> <p><a href="http://www.clinicaltrials.gov/ct2/show/NCT00937456">NCT00937456</a> (ClinicalTrials.gov)</p

Trials

BACKGROUND: Postoperative upper gastrointestinal fistula (PUGIF) is a devastating complication, leading to high mortality (reaching up to 80%), increased length of hospital stay, reduced health-related quality of life and increased health costs. Nutritional support is a key component of therapy in such cases, which is related to the high prevalence of malnutrition. In the prophylactic setting, enteral nutrition (EN) is associated with a shorter hospital stay, a lower incidence of severe infectious complications, lower severity of complications and decreased cost compared to total parenteral nutrition (TPN) following major upper gastrointestinal (GI) surgery. There is little evidence available for the curative setting after fistula occurrence. We hypothesize that EN increases the 30-day fistula closure rate in PUGIF, allowing better health-related quality of life without increasing the morbidity or mortality. METHODS/DESIGN: The NUTRILEAK trial is a multicenter, randomized, parallel-group, open-label phase III trial to assess the efficacy of EN (the experimental group) compared with TPN (the control group) in patients with PUGIF. The primary objective of the study is to compare EN versus TPN in the treatment of PUGIF (after esophagogastric resection including bariatric surgery, duodenojejunal resection or pancreatic resection with digestive tract violation) in terms of the 30-day fistula closure rate. Secondary objectives are to evaluate the 6-month postrandomization fistula closure rate, time of first fistula closure (in days), the medical- and surgical treatment-related complication rate at 6 months after randomization, the fistula-related complication rate at 6 months after randomization, the type and severity of early (30 days after randomization) and late fistula-related complications (over 30 days after randomization), 30-day and 6-month postrandomization mortality rate, nutritional status at day 30, day 60, day 90 and day 180 postrandomization, the mean length of hospital stay, the patient's health-related quality of life (by self-assessment questionnaire), oral feeding time and direct costs of treatment. A total of 321 patients will be enrolled. DISCUSSION: The two nutritional supports are already used in daily practice, but most surgeons are reluctant to use the enteral route in case of PUGIF. This study will be the first randomized trial testing the role of EN versus TPN in PUGIF. TRIAL REGISTRATION: ClinicalTrials.gov: NCT03742752. Registered on 14 November 2018.This research program is funded by the French Ministry of Health through Programme Hospitalier de Recherche Clinique 2016

Complications infectieuses en chirurgie non colo-rectale (facteurs de risque et élaboration de score prédictif)

De 1982 à 1986, une base de données de 5798 patients ayant eu une chirurgie abdominale non colo-rectale a été établi à partir de trois études randomisées prospectives multicentriques. Une analyse multivariée a été réalisée à l'aide d'une régression logistique non conditionnelle exprimée en oddsratio. Le taux de complications infectieuses globales, d'infection du site opératoire (ISO), de complications infectieuses pariétales, profondes avec ou sans fistules étaient respectivement de 13,3 %, 4,05 %, 2,2 %, 2,18 % et 1,38 %. Les facteurs de risque d'ISO et de complications infectieuses globales sont différents, car le seul facteur commun est la réalisation d'une suture ou d'une anastomose digestive. Un score prédictif a été établi en chirurgie abdominale propre (strate 1) sans mise en place d'un matériel prothétique : - 4,9 + (1,5 x cirrhose) + (autre comorbidité) + (0,8 x sonde urinaire). Dans le taux de complication infectieuse, alors que dans le sous groupe à haut risque (score [supérieur] - 4,5) l'administration d'une antibioprophylaxie réduisait significativement le taux d'infection du site opératoire et d'abcès de paroi de 58 % et 69 %. Un score prédictif a été établi après cure d'hernie inguinale sans mise en place d'un matériel prothétique : - 4,7 + (0,95 x âge >= 75 ans (1,1 obésite) + (2,1x sonde urinaire). Dans le sous groupe à faible risque, l'administration d'une antibioprophylaxie ne réduisait pas le taux de complication infectieuse, alors que dans le sous groupe à haut risque l'administration d'une antibioprophylaxie réduisait significativement le taux d'infection du site opératoire, d'infection globale, et d'abcès de paroi de 72 %, 67 % et 76,8 % respectivement. Ce score validé sur une autre série retrouve les mêmes résultatsLYON1-BU.Sciences (692662101) / SudocSudocFranceF

The Distance between the Pylorus and Left Vagus Nerve during Sleeve Gastrectomy

International audienceThe sleeve gastrectomy (SG) can be performed with or without antral preservation (distance from the pylorus <50 mm). The objective of this study was to evaluate the distance between the pylorus and the end of the left vagus nerve in order to determine whether it could be used as a constant anatomical landmark to start gastric transection. This was a prospective, nonrandomized study of 120 patients undergoing SG from January to October 2018. The distance measurement between pylorus and vagus nerve was performed at the beginning of the SG. The primary endpoint was the distance between the beginning of the pylorus and the end of the second branch of the vagus nerve on the upper edge of the antrum. The secondary endpoints was the correlation factors between the preoperative data and the position of the end of the vagus nerve. A total of 120 patients, with a mean body mass index of 42.2 kg/m(2), underwent primary SG. The mean distance between pylorus and the end of the vagus nerve was 50.4 mm (35-64) on the upper part of the antrum. When considering the inferior part of the antrum, the minimum distance was 50 mm. No correlations were found between preoperative data and distance measurements. The vagus nerve can be considered as a constant and reliable anatomical landmark for performing SG with antral preservation. However, no correlation was found between the preoperative data and the location of the end of the vagus nerve. Clin. Anat., 2019. (c) 2019 Wiley Periodicals, Inc

Current challenges in providing bariatric surgery in France

International audienceBariatric surgery is a well-accepted procedure for severe and massive obesity management. We aimed to determine trends, geographical variations, and factors influencing bariatric surgery and the choice of procedure in France in a large observational study.The Health Insurance Fund for Salaried Workers (Caisse National Assurance Maladie Travailleurs Salariés) covers about 86% of the French population. The Système National d'Information Inter-régimes de l'Assurance Maladie database contains individualized and anonymized patient data on all reimbursements for healthcare expenditure. All types of primary bariatric procedures (Roux-en-Y gastric bypass [RYGB] or omega loop, adjustable gastric banding [AGB], or longitudinal sleeve gastrectomy [LSG]) performed during 2011 to 2013 were systematically recorded. Surgical techniques performed by region of residence and age-range relative risks with 95% confidence intervals of undergoing LSG or RYGB versus AGB were computed.In 2013, LSG was performed more frequently than RYGB and AGB (57% vs 31% and 13%, respectively). A total of 41,648 patients underwent a bariatric procedure; they were predominantly female (82%) with a mean (±standard deviation) age of 40 (±12) years and a body mass index ≥40 kg/m for 68% of them. A total of 114 procedures were performed in patients younger than 18 years and 2381 procedures were performed in patients aged 60 years and older. Beneficiaries of the French universal health insurance coverage for low-income patients were more likely to undergo surgery than the general population. Large nationwide variations were observed in the type choice of bariatric surgical procedures. Significant positive predictors for undergoing RYGB compared to those for undergoing AGB were as follows: referral to a center performing a large number of surgeries or to a public hospital, older age, female gender, body mass index ≥50 kg/m, and treatment for obstructive sleep apnea syndrome, diabetes, or depression. Universal health insurance coverage for low-income patients was inversely correlated with the probability of RYGB.Differences in access to surgery have been observed in terms of the patient's profile, geographical variations, and predictors of types of procedures. Several challenges must be met when organizing the medical care of this growing number of patients, when delivering surgery through qualified centers while assuring the quality of long-term follow-up for all patients