Chatbots are artificial communication systems becoming increasingly popular and not all their security questions are clearly solved. People use chatbots for assistance in shopping, bank communication, meal delivery, healthcare, cars, and many other actions.However, it brings an additional security risk and creates serious security challenges which have to be handled. Understanding the underlying problems requires defining the crucial steps in the techniques used to design chatbots related to security. There are many factors increasing security threats and vulnerabilities. All of them are comprehensively studied, and security practices to decrease security weaknesses are presented. Modern chatbots are no longer rule-based models, but they employ modern natural language and machine learning techniques. Such techniques learn from a conversation, which can contain personal information. The paper discusses circumstances under which such data can be used and how chatbots treat them. Many chatbots operate on a social/messaging platform, which has their terms and conditions about data. The paper aims to present a comprehensive study of security aspects in communication with chatbots. The article could open a discussion and highlight the problems of data storage and usage obtained from the communication user-chatbot and propose some standards to protect the user. K E Y W O R D Schat, chatbots, data protection, GDPR, security, virtual assistants * A bot is sometimes referred to as a chatbot, but to be precise, a bot is a computer program (tool) that automates processes. A chatbot is a sub-genre of the bot environment with a focus on talking or conversation. Some companies instead of Chatbot use the name 'Conversational AI' or ' AI chatbots' to highlight that their chatbot is powered by machine learning and information retrieval techniques. In this article the term 'chatbot' is used for all types of chatbots.This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

IntroductionThe liver is the most common site of colorectal metastases (colorectal liver metastases – CLM). Surgical treatment in combination with oncological therapy is the only potentially curative method. Unfortunately, only 10–25% of patients are suitable for surgery. Traditionally, open liver resection (OLR) is usually performed. However, laparoscopic liver resection (LLR) has become popular worldwide in the last two decades.AimTo evaluate the effectiveness and benefits of radiofrequency minor LLR of CLM in comparison with OLR.Material and methodsThe indication for surgery was CLM and the possibility to perform minor laparoscopic or OLR not exceeding two hepatic segments according to Couinaud's classification.ResultsSixty-six minor liver resections for CLM were performed. Twenty-five (37.9%) patients underwent a laparoscopic approach and 41 (62.1%) patients underwent OLR. The mean operative time was 166.4 min for LLR and 166.8 min for OLR. Average blood loss was 132.3 ±218.0 ml during LLR and 149.5 ±277.5 ml during OLR. Length of hospital stay was 8.4 ±2.0 days for LLR and 10.5 ±5.8 days for OLR. All resections were R0. There was no case of mortality. Postoperative complications were recognized in 9 (13.6%) patients: 8 in the group of OLR patients and 1 in the LLR group. The median survival time for LLR was 70.5 months and for OLR 61.9 months. The 5-year overall survival rate was higher for LLR vs. OLR – 82.1% vs. 69.8%. The average length of disease-free interval after LLR was greater (52.2 months) in comparison with OLR (49.4%). The 5-year disease-free interval was 63.2% for LLR and 58% for OLR.ConclusionsOutcomes and oncological radicality of minor laparoscopic liver resections of CLM are comparable to outcomes of OLR.

A comparative modelling exercise involving several independent teams from the DECOVALEX-2015 project is presented in this paper. The exercise is based on various laboratory experiments that have been carried out in the framework of a French research program called SEALEX and conducted by the IRSN. The program focuses on the long-term performance of swelling clay-based sealing systems that provide an important contribution to the safety of underground nuclear waste disposal facilities. A number of materials are being considered in the sealing systems; the current work focuses on a 70/30 MX80 bentonite-sand mixture compacted at dry densities between 1.67 Mg/m 3 and 1.97 Mg/m 3. The improved understanding of the full set of hydro-mechanical processes affecting the behaviour of an in-situ sealing system requires both experiments ranging from small-scale laboratory tests to full-scale field emplacement studies, and coupled hydro-mechanical models that are able to explain the observations in the experiments. The approach was to build models of increasing complexity starting for the simplest laboratory experiments and building towards the full-scale in situ experiments. Following this approach, two sets of small-scale laboratory experiments have been performed and modelled. The first set of experiments involve characterising the hydro-mechanical behaviour of the bentonite-sand mixture by means of (i) water retention tests under both constant volume and free swell conditions, (ii) infiltration test under constant volume condition, and (iii) swelling and compression tests under suction control conditions. The second, more complex, experiment is a 1/10th scale mock-up of a larger scale in situ experiment. Modelling of the full-scale experiment is described in a companion paper. A number of independent teams have worked towards modelling these experiments using different conceptual models, codes, and input parameters. Their results are compared and discussed. This exercise has enabled an improved modelling of the bentonite-sand mixture behaviour, in particular accounting for the dependence of its retention curve on the dry density. Moreover, it has shown the importance of the technological voids on the short-term behaviour of the sealing system. .

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