Αποτίμηση φέρουσας ικανότητας πολυώροφου κτηρίου από οπλισμένο σκυρόδεμα στο Πολύγωνο - Αθήνα

Εθνικό Μετσόβιο Πολυτεχνείο--Μεταπτυχιακή Εργασία. Διεπιστημονικό-Διατμηματικό Πρόγραμμα Μεταπτυχιακών Σπουδών (Δ.Π.Μ.Σ.) “Δομοστατικός Σχεδιασμός και Ανάλυση των Κατασκευών

Towards Human Society-inspired Decentralized DNN Inference

In human societies, individuals make their own decisions and they may select if and who may influence it, by e.g., consulting with people of their acquaintance or experts of a field. At a societal level, the overall knowledge is preserved and enhanced by individual person empowerment, where complicated consensus protocols have been developed over time in the form of societal mechanisms to assess, weight, combine and isolate individual people opinions. In distributed machine learning environments however, individual AI agents are merely part of a system where decisions are made in a centralized and aggregated fashion or require a fixed network topology, a practice prone to security risks and collaboration is nearly absent. For instance, Byzantine Failures may tamper both the training and inference stage of individual AI agents, leading to significantly reduced overall system performance. Inspired by societal practices, we propose a decentralized inference strategy where each individual agent is empowered to make their own decisions, by exchanging and aggregating information with other agents in their network. To this end, a ”Quality of Inference” consensus protocol (QoI) is proposed, forming a single commonly accepted inference rule applied by every individual agent. The overall system knowledge and decisions on specific manners can thereby be stored by all individual agents in a decentralized fashion, employing e.g., blockchain technology. Our experiments in classification tasks indicate that the proposed approach forms a secure decentralized inference framework, that prevents adversaries at tampering the overall process and achieves comparable performance with centralized decision aggregation methods

Mechanistic studies on the molecular toxicology of the carcinogen PhIP: the role of microRNAs

The effect of environmental factors in cellular processes has been an area of interest for decades. Within this research field, emerging research niches appear concominantly with advances in molecular biology and genetics. One such field is the one of molecular toxicology, which investigates the molecular and cellular events that certain chemicals trigger. Chemicals that present genotoxic properties are of particular interest based on the potential contribution to the aetiology of cancer that the discoveries of their effects might provide. A group of chemicals that belong to this category are heterocyclic amines, organic compounds that are formed during the cooking of red meat from the pyrolysis of aminoacids. Research into heterocyclic amines has created a well established description for their ability to create DNA adducts that lead to mutations. Recent reports from our laboratory however, indicated that certain heterocyclic amines, and in particular 2-amino-1-methyl-6-phenylimidazo [4,5-b] pyridine (PhIP), present with molecular effects that are non genotoxic but nevertheless carcinogenic and are very similar to those induce by the natural hormone estradiol in breast cancer cells. Based on these findings this thesis set out to investigate whether these non-genotoxic effects of PhIP also extend to epigenetic mechanisms of gene expression control, and more specifically microRNA expression regulation. MicroRNAs are a class of small non-coding RNA molecules that posttrasncriptionally regulate gene expression and are involved in an array of process including carcinogenesis. Our results showed that PhIP, as well as estradiol, drive differential regulation of microRNAs and that these effects are very similar amongst the two compounds. This deregulation of microRNAs could be an attributing factor to the cancer promoting characteristics of both estradiol and PhIP and they extend the estrogenic character of this heterocyclic amine to the area of epigenetic regulation, and microRNAs in particular.Open Acces

A step-by-step diagnosis of exclusion in a twin pregnancy with acute respiratory failure due to non-fatal amniotic fluid embolism: a case report

<p>Abstract</p> <p>Introduction</p> <p>Respiratory failure may develop during the later stages of pregnancy and is usually associated with tocolysis or other co-existing conditions such as pneumonia, sepsis, pre-eclampsia or amniotic fluid embolism syndrome.</p> <p>Case presentation</p> <p>We present the case of a 34-year-old healthy woman with a twin pregnancy at 31 weeks and 6 days who experienced acute respiratory failure, a few hours after administration of tocolysis (ritodrine), due to preterm premature rupture of the membranes. Her chest discomfort was significantly ameliorated after the ritodrine infusion was stopped and a Cesarean section was performed 48 hours later under spinal anesthesia; however, 2 hours after surgery she developed severe hypoxemia, hypotension, fever and mild coagulopathy. The patient was intubated and transferred to the intensive care unit where she made a quick and uneventful recovery within 3 days. As there was no evidence for drug- or infection-related thromboembolic or myocardial causes of respiratory failure, we conclude that our patient experienced a rare type of non-fatal amniotic fluid embolism.</p> <p>Conclusion</p> <p>In spite of the lack of solid scientific support for our diagnosis, we conclude that our patient suffered an uncommon type of amniotic fluid embolism syndrome and we believe that this report highlights the need for extreme vigilance and a high index of suspicion for such a diagnosis in any pregnant individual.</p

Behçet’s Disease, Associated Large Vessel Thrombosis, and Coexistent Thrombophilia: A Distinct Nosological Entity?

Behçet’s disease (BD) represents a multisystemic disorder that combines features of immune-mediated diseases and autoinflammatory disorders. Even though it is recognized that every type or size of vessel can be affected in this disease, there is an inability to describe a coherent model that sufficiently explains the predilection of certain patients with BD for manifesting severe large vessel thrombosis. The inconsistent epidemiologic data and the complex genetic background of BD, along with the controversy of multiple international studies regarding the coexistence of thrombophilia in patients with BD and large vessel thrombosis, make us think that a percentage of these patients may actually suffer from a distinct clinical entity. The stimulus for this concept arose from the clinical observation of three male patients who were admitted to our clinic due to extended vena cava thrombosis. On the occasion of those clinically and laboratory resembling cases, we performed a literature review concerning the epidemiology of BD, associated thrombosis, and coexistent thrombophilic factors, in order to present some evidence, which sustains our hypothesis that certain patients with large vessel thrombosis, who share features of BD and coexistent thrombophilia, should actually be further investigated for the possibility of suffering from a distinct nosological entity

Transient Monoclonal Gammopathy Induced by Disseminated Staphylococcus aureus

Monoclonal gammopathy reflects a serological disorder suggesting a plasma cell dyscrasia or a B-cell abnormality. However, it may occasionally be encountered as a transient manifestation in the course of several diseases including infections. This is the first reported case of a transient monoclonal gammopathy IgG lambda light chain associated with a Staphylococcus aureus infection that was complicated with renal abscess and vertebral spondylodiscitis in a previously healthy 68-year-old male. We observed a complete resolution of the gammopathy within three months of medical treatment before the entire restoration of all clinical and laboratory findings. Many invasive and cost-intensive diagnostic procedures had preceded the exclusion of a malignancy. The clinical significance and the exact pathogenesis of transient monoclonality are poorly understood and remain a matter of speculation