Connectionist modal logic: Representing modalities in neural networks

AbstractModal logics are amongst the most successful applied logical systems. Neural networks were proved to be effective learning systems. In this paper, we propose to combine the strengths of modal logics and neural networks by introducing Connectionist Modal Logics (CML). CML belongs to the domain of neural-symbolic integration, which concerns the application of problem-specific symbolic knowledge within the neurocomputing paradigm. In CML, one may represent, reason or learn modal logics using a neural network. This is achieved by a Modalities Algorithm that translates modal logic programs into neural network ensembles. We show that the translation is sound, i.e. the network ensemble computes a fixed-point meaning of the original modal program, acting as a distributed computational model for modal logic. We also show that the fixed-point computation terminates whenever the modal program is well-behaved. Finally, we validate CML as a computational model for integrated knowledge representation and learning by applying it to a well-known testbed for distributed knowledge representation. This paves the way for a range of applications on integrated knowledge representation and learning, from practical reasoning to evolving multi-agent systems

Síndrome de Ménière: diagnóstico etiológico

The correct identification of the etiology of Ménière’s syndrome is possible in up to 50% of all cases; once the underlying cause is identified, it can be managed, and that usually results in significant improvement in the set of symptoms. The objective of the present paper is to discuss the main diseases associated to the genesis of Ménière’s in terms of prevalence, etiopathogenic mechanisms, and prognostic implications. In addition, the paper presents a flow chart that can serve as a guide for etiologic research in Ménière’s syndrome.A correta identificação da etiologia da síndrome de Ménière, alcançada em até 50% dos casos, permite, via de regra, uma melhora significativa do quadro, através do manejo da doença de base. O presente estudo objetiva discutir as principais doenças possivelmente associadas à gênese da síndrome de Ménière, enfocando prevalência, mecanismo etiopatogênico, implicação prognóstica. Além disso, apresentamos um fluxograma que serve como guia de busca etiológica para a síndrome de Ménièr

Radiofrequency cardiac ablation with catheters placed on opposing sides of the ventricular wall: Computer modelling comparing bipolar and unipolar modes

Purpose: The aim of this study was to compare the efficacy of bipolar (BM) vs. unipolar (UM) mode of radiofrequency ablation (RFA) in terms of creating transmural lesions across the interventricular septum (IVS) and ventricular free wall (VFW). Materials and methods: We built computational models to study the temperature distributions and lesion dimensions created by BM and UM on IVS and VFW during RFA. Two different UM types were considered: sequential (SeUM) and simultaneous (SiUM). The effect of ventricular wall thickness, catheter misalignment, epicardial fat, and presence of air in the epicardial space were also studied. Results: Regarding IVS ablation, BM created transmural and symmetrical lesions for wall thicknesses up to 15 mm. SeUM and SiUM were not able to create transmural lesions with IVS thicknesses >= 12.5 and 15 mm, respectively. Lesions were asymmetrical only with SeUM. For VFW ablation, BM also created transmural lesions for wall thicknesses up to 15 mm. However, with SeUM and SiUM transmurality was obtained for VFW thicknesses <= 7.5 and 12.5 mm, respectively. With the three modes, VFW lesions were always asymmetrical. In the scenario with air or a fat tissue layer on the epicardial side, only SiUM was capable of creating transmural lesions. Overall, BM was superior to UM in IVS and VFW ablation when the catheters were not aligned. Conclusions: Our findings suggest that BM is more effective than UM in achieving transmurality across both ventricular sites, except in the situation of the epicardial catheter tip surrounded by air or placed over a fat tissue layer.This work received financial support from the Spanish 'Plan Nacional de I+D+I del Ministerio de Ciencia e Innovacion' (TEC2011-27133-C02-01), and from the Universitat Politecnica de Valencia (PAID-06-11 Ref. 1988). A. Gonzalez-Suarez is the recipient of a Grant VaLi+D (ACIF/2011/194) from the Generalitat Valenciana, Spain. The authors alone are responsible for the content and writing of the paper.González Suárez, A.; Trujillo Guillen, M.; Koruth, J.; D'avila, A.; Berjano, E. (2014). Radiofrequency cardiac ablation with catheters placed on opposing sides of the ventricular wall: Computer modelling comparing bipolar and unipolar modes. International Journal of Hyperthermia. 30(6):372-384. https://doi.org/10.3109/02656736.2014.949878S372384306SIVAGANGABALAN, G., BARRY, M. A., HUANG, K., LU, J., POULIOPOULOS, J., THOMAS, S. P., … KOVOOR, P. (2010). Bipolar Ablation of the Interventricular Septum is More Efficient at Creating a Transmural Line than Sequential Unipolar Ablation. Pacing and Clinical Electrophysiology, 33(1), 16-26. doi:10.1111/j.1540-8159.2009.02602.xNagashima, K., Watanabe, I., Okumura, Y., Ohkubo, K., Kofune, M., Ohya, T., … Hirayama, A. (2011). Lesion Formation by Ventricular Septal Ablation With Irrigated Electrodes. Circulation Journal, 75(3), 565-570. doi:10.1253/circj.cj-10-0870D’ Avila, A., Houghtaling, C., Gutierrez, P., Vragovic, O., Ruskin, J. N., Josephson, M. E., & Reddy, V. Y. (2004). Catheter Ablation of Ventricular Epicardial Tissue. Circulation, 109(19), 2363-2369. doi:10.1161/01.cir.0000128039.87485.0bDukkipati, S. R., d’ Avila, A., Soejima, K., Bala, R., Inada, K., Singh, S., … Reddy, V. Y. (2011). Long-Term Outcomes of Combined Epicardial and Endocardial Ablation of Monomorphic Ventricular Tachycardia Related to Hypertrophic Cardiomyopathy. Circulation: Arrhythmia and Electrophysiology, 4(2), 185-194. doi:10.1161/circep.110.957290Sosa, E., Scanavacca, M., d’ Avila, A., Oliveira, F., & Ramires, J. A. F. (2000). Nonsurgical transthoracic epicardial catheter ablation to treat recurrent ventricular tachycardia occurring late after myocardial infarction. Journal of the American College of Cardiology, 35(6), 1442-1449. doi:10.1016/s0735-1097(00)00606-9Nagashima, K., Watanabe, I., Okumura, Y., Sonoda, K., Kofune, M., Mano, H., … Hirayama, A. (2012). Epicardial Ablation With Irrigated Electrodes. Circulation Journal, 76(2), 322-327. doi:10.1253/circj.cj-11-0984Berjano, E. J. (2006). BioMedical Engineering OnLine, 5(1), 24. doi:10.1186/1475-925x-5-24Abraham, J. P., & Sparrow, E. M. (2007). A thermal-ablation bioheat model including liquid-to-vapor phase change, pressure- and necrosis-dependent perfusion, and moisture-dependent properties. International Journal of Heat and Mass Transfer, 50(13-14), 2537-2544. doi:10.1016/j.ijheatmasstransfer.2006.11.045Jo, B., & Aksan, A. (2010). Prediction of the extent of thermal damage in the cornea during conductive keratoplasty. Journal of Thermal Biology, 35(4), 167-174. doi:10.1016/j.jtherbio.2010.02.004HAINES, D. E., & WATSON, D. D. (1989). Tissue Heating During Radiofrequency Catheter Ablation: A Thermodynamic Model and Observations in Isolated Perfused and Superfused Canine Right Ventricular Free Wall. Pacing and Clinical Electrophysiology, 12(6), 962-976. doi:10.1111/j.1540-8159.1989.tb05034.xZhao, G., Zhang, H.-F., Guo, X.-J., Luo, D.-W., & Gao, D.-Y. (2007). Effect of blood flow and metabolism on multidimensional heat transfer during cryosurgery. Medical Engineering & Physics, 29(2), 205-215. doi:10.1016/j.medengphy.2006.03.005Chang, I. A., & Nguyen, U. D. (2004). BioMedical Engineering OnLine, 3(1), 27. doi:10.1186/1475-925x-3-27Whitney, J., Carswell, W., & Rylander, N. (2013). Arrhenius parameter determination as a function of heating method and cellular microenvironment based on spatial cell viability analysis. International Journal of Hyperthermia, 29(4), 281-295. doi:10.3109/02656736.2013.802375Pearce, J. A. (2013). Comparative analysis of mathematical models of cell death and thermal damage processes. International Journal of Hyperthermia, 29(4), 262-280. doi:10.3109/02656736.2013.786140Doss, J. D. (1982). Calculation of electric fields in conductive media. Medical Physics, 9(4), 566-573. doi:10.1118/1.595107Watanabe, I., Nuo, M., Okumura, Y., Ohkubo, K., Ashino, S., Kofune, M., … Hirayama, A. (2010). Temperature-Controlled Cooled-Tip Radiofrequency Ablation in Left Ventricular Myocardium. International Heart Journal, 51(3), 193-198. doi:10.1536/ihj.51.193Yokoyama, K., Nakagawa, H., Wittkampf, F. H. M., Pitha, J. V., Lazzara, R., & Jackman, W. M. (2006). Comparison of Electrode Cooling Between Internal and Open Irrigation in Radiofrequency Ablation Lesion Depth and Incidence of Thrombus and Steam Pop. Circulation, 113(1), 11-19. doi:10.1161/circulationaha.105.540062Kumar, P., Mounsey, J. P., Gehi, A. K., Schwartz, J. D., & Chung, E. H. (2013). Use of a closed loop irrigated catheter in epicardial ablation of ventricular tachycardia. Journal of Interventional Cardiac Electrophysiology, 38(1), 35-42. doi:10.1007/s10840-013-9799-1Schutt, D., Berjano, E. J., & Haemmerich, D. (2009). Effect of electrode thermal conductivity in cardiac radiofrequency catheter ablation: A computational modeling study. International Journal of Hyperthermia, 25(2), 99-107. doi:10.1080/02656730802563051Gopalakrishnan, J. (2002). A Mathematical Model for Irrigated Epicardial Radiofrequency Ablation. Annals of Biomedical Engineering, 30(7), 884-893. doi:10.1114/1.1507845Suárez, A. G., Hornero, F., & Berjano, E. J. (2010). Mathematical Modeling of Epicardial RF Ablation of Atrial Tissue with Overlying Epicardial Fat. The Open Biomedical Engineering Journal, 4(1), 47-55. doi:10.2174/1874120701004020047Haemmerich, D., Chachati, L., Wright, A. S., Mahvi, D. M., Lee, F. T., & Webster, J. G. (2003). Hepatic radiofrequency ablation with internally cooled probes: effect of coolant temperature on lesion size. IEEE Transactions on Biomedical Engineering, 50(4), 493-500. doi:10.1109/tbme.2003.809488Koruth, J. S., Dukkipati, S., Miller, M. A., Neuzil, P., d’ Avila, A., & Reddy, V. Y. (2012). Bipolar irrigated radiofrequency ablation: A therapeutic option for refractory intramural atrial and ventricular tachycardia circuits. Heart Rhythm, 9(12), 1932-1941. doi:10.1016/j.hrthm.2012.08.001González-Suárez, A., Trujillo, M., Burdío, F., Andaluz, A., & Berjano, E. (2012). Feasibility study of an internally cooled bipolar applicator for RF coagulation of hepatic tissue: Experimental and computational study. International Journal of Hyperthermia, 28(7), 663-673. doi:10.3109/02656736.2012.716900Agah, R., Gandjbakhche, A. H., Motamedi, M., Nossal, R., & Bonner, R. F. (1996). Dynamics of temperature dependent optical properties of tissue: dependence on thermally induced alteration. IEEE Transactions on Biomedical Engineering, 43(8), 839-846. doi:10.1109/10.508546Haines, D. E. (2011). Letter by Haines Regarding Article, «Direct Measurement of the Lethal Isotherm for Radiofrequency Ablation of Myocardial Tissue». Circulation: Arrhythmia and Electrophysiology, 4(5). doi:10.1161/circep.111.965459Wood, M., Goldberg, S., Lau, M., Goel, A., Alexander, D., Han, F., & Feinstein, S. (2011). Direct Measurement of the Lethal Isotherm for Radiofrequency Ablation of Myocardial Tissue. Circulation: Arrhythmia and Electrophysiology, 4(3), 373-378. doi:10.1161/circep.110.961169Jain, M. K., & Wolf, P. D. (2000). A Three-Dimensional Finite Element Model of Radiofrequency Ablation with Blood Flow and its Experimental Validation. Annals of Biomedical Engineering, 28(9), 1075-1084. doi:10.1114/1.131021

Neural Networks for State Evaluation in General Game Playing

Abstract. Unlike traditional game playing, General Game Playing is concerned with agents capable of playing classes of games. Given the rules of an unknown game, the agent is supposed to play well without human intervention. For this purpose, agent systems that use deterministic game tree search need to automatically construct a state value function to guide search. Successful systems of this type use evaluation functions derived solely from the game rules, thus neglecting further improvements by experience. In addition, these functions are fixed in their form and do not necessarily capture the game’s real state value function. In this work we present an approach for obtaining evaluation functions on the basis of neural networks that overcomes the aforementioned problems. A network initialization extracted from the game rules ensures reasonable behavior without the need for prior training. Later training, however, can lead to significant improvements in evaluation quality, as our results indicate.

Projeto Quintais Orgânicos de Frutas: Contribuição para a segurança alimentar em áreas rurais, indígenas e urbanas.

O Projeto Quintais tem como objetivo contribuir com a sustentabilidade social, econômica e ambiental de públicos em situação de vulnerabilidade e de risco social, econômico e alimentar. Para a composição dos quintais, são adotadas três plantas frutíferas, provenientes de um conjunto de 20 espécies, sementes de feijão e milho, mudas de três cultivares de batata doce, mudas de uma espécie forrageira e de doze espécies de plantas medicinais, totalizando 38 produtos cultivados no interior de cada Quintal. As tecnologias desenvolvidas no Projeto, tais como novas cultivares, conhecimento das propriedades funcionais dos alimentos que compõem o Quintal, assim como o processo de verticalização ou transformação e agregação de valor aos alimentos deverão promover a capacitação e a inclusão social de beneficiários, assim como, viabilizar a geração de emprego e renda.Anais da Reunião Técnica sobre Agroecologia: Agroecologia, Resiliência e Bem Viver, 2021, Pelotas

Hepatitis C in Brazil: lessons learned with boceprevir and telaprevir

In 2012, the first-generation protease inhibitors telaprevir (TVR) and boceprevir (BOC) were introduced in the Brazilian health system for treatment of chronic hepatitis C, after their approval by the National Committee for Health Technology Incorporation (CONITEC). However, these medicines were discontinued in 2015. The short period of use in therapy and their high cost require a discussion about the consequences for patients and for the health system of the early incorporation of new therapies. The article presents a qualitative analysis of the incorporation process of both medications in Brazil and the results of a multicenter study that included patients treated with BOC or TVR between January 2011 and December 2015 in five Brazilian cities. The study included 855 patients (BOC: n=247) and (TVR: n=608). The document analysis showed that CONITEC’s decision to incorporate BOC and TVR was based on results of phase III clinical trials that compared sustained virologic response (SVR) rates of patients treated with BOC and TVR with rates of those that received placebo. However, these studies included a low percentage of cirrhotic patients. The SVR rates observed in this multicenter study were worse than clinical trials pointed out (BOC: 45.6%; TVR: 51.8%), but similar to those achieved with previously adopted therapies. The discontinuation rate due to adverse events was (BOC: 15.4%; TVR: 12.7%). Based on these unsatisfactory results, the study brings a discussion that goes beyond the therapy outcomes, exploring the incorporation of these high-cost medicines and the related decision-making process, contributing to future decisions in medicine policies and in the treatment of chronic hepatitis C

2019 HRS/EHRA/APHRS/LAHRS expert consensus statement on catheter ablation of ventricular arrhythmias: Executive summary

Ventricular arrhythmias are an important cause of morbidity and mortality and come in a variety of forms, from single premature ventricular complexes to sustained ventricular tachycardia and fibrillation. Rapid developments have taken place over the past decade in our understanding of these arrhythmias and in our ability to diagnose and treat them. The field of catheter ablation has progressed with the development of new methods and tools, and with the publication of large clinical trials. Therefore, global cardiac electrophysiology professional societies undertook to outline recommendations and best practices for these procedures in a document that will update and replace the 2009 EHRA/HRS Expert Consensus on Catheter Ablation of Ventricular Arrhythmias. An expert writing group, after reviewing and discussing the literature, including a systematic review and meta-analysis published in conjunction with this document, and drawing on their own experience, drafted and voted on recommendations and summarized current knowledge and practice in the field. Each recommendation is presented in knowledge byte format and is accompanied by supportive text and references. Further sections provide a practical synopsis of the various techniques and of the specific ventricular arrhythmia sites and substrates encountered in the electrophysiology lab. The purpose of this document is to help electrophysiologists around the world to appropriately select patients for catheter ablation, to perform procedures in a safe and efficacious manner, and to provide follow-up and adjunctive care in order to obtain the best possible outcomes for patients with ventricular arrhythmias