On the Analysis of the Contact Conditions in Temporomandibular Joint Prostheses

Temporomandibular joint replacement (TMJR) is a complex surgical procedure in which the artificial joints available must assure the anatomical reconstruction and guarantee a good range of the natural temporomandibular joint (TMJ) movements. With this aim, different types of TMJ prostheses, including the stock prosthetic system and custom-made prostheses, are being currently implanted. Although temporomandibular joint replacements (TMJRs) are expected to accomplish their function during a number of years, they might actually fail and need to be replaced. This paper analyzes different design factors affecting the contact stress distributions within the TMJ prosthesis interface, which are consequently involved in their deterioration and final failure of the prosthetic device. With this purpose, a numerical model based on finite elements has been carried out in order to evaluate the stress states attained in different prosthesis configurations corresponding to general types of TMJ prostheses. On the other hand, the actual degradation of resected implants has been evaluated via optical microscopy. The linkage between the numerical simulations performed and experimental evidence allowed the authors to establish the different wear and damage mechanisms involved in the failure of stock TMJ prostheses. Indeed, the results obtained show that the contact stresses at the interface between the mandible and the glenoid fossa components play a key role in the failure process of the TMJR devices

Global Sustainability Crossroads: A Participatory Simulation Game to Educate in the Energy and Sustainability Challenges of the 21st Century

Producción CientíficaThere is a general need to facilitate citizens’ understanding of the global sustainability problem with the dual purpose of raising their awareness of the seriousness of the problem and helping them get closer to understanding the complexity of the solutions. Here, the design and application of the participatory simulation game Global Sustainability Crossroads is described, based on a global state-of-the-art energy–economy–environment model, which creates a virtual scenario where the participants are confronted with the design of climate mitigation strategies as well as the social, economic, and environmental consequences of decisions. The novelty of the game rests on the global scope and the representation of the drivers of anthropogenic emissions within the MEDEAS-World model, combined with a participatory simulation group dynamic flexible enough to be adapted to a diversity of contexts and participants. The performance of 13 game workshops with ~420 players has shown it has a significant pedagogical potential: the game is able to generate discussions on crucial topics which are usually outside the public realm such as the relationship between economic growth and sustainability, the role of technology, how human desires are limited by biophysical constraints or the possibility of climate tipping point

Aportaciones sobre la implantación del Plan Bolonia. Un giro copernicano para los alumnos

La implantación del Sistema del denominado Plan Bolonia no sólo representa un reto para el profesorado sino también para el alumnado, acostumbrado a seguir la clase de lejos, participar poco en ella y darse un atracón de estudiar los días previos al examen. Un sistema basado en la asistencia a clase de forma activa, haciendo ejercicios y trabajos en grupo asiduamente, representa para muchos de nuestros alumnos un giro copernicano. En este trabajo se presenta el seguimiento de una cierta evaluación continua en una asignatura que aunque está situada en 2º curso es específica de los estudios que nos ocupa de la Ingeniería Naval, lo que podría dar lugar a pensar un cierto interés o al menos motivación por parte del alumno. Una vez planteada la metodología de la evaluación continua, se analizan la participación de los alumnos, su asistencia a clase, la evolución de los abandonos y la influencia de este sistema en los resultados académicos. Los resultados pondrán de manifiesto las dificultades que la implantación del Plan Bolonia tiene entre el alumnado acostumbrado a otros esquemas de funcionamiento

Modelling of sectoral energy demand through energy intensities in MEDEAS integrated assessment model

Producción CientíficaThe estimation of future energy demand is a key factor for the development of effective alternative policies towards a low carbon economy. This paper describes a novel method to estimate the energy demand in the new integrated assessment framework MEDEAS based on the projection of sectoral final energy intensities. The dynamic of each of the sectoral final energy intensity is broken down into (1) improvement in energy efficiency and (2) substitution of the final energy. The speed of changes in these factors depend on physical supply-demand unbalances in the market, climate mitigation and other energy saving policies and the perception of scarcity of the different economic agents. The simulated case studies in MEDEAS-World under the narrative of the Business-as-usual (BAU) scenario have allowed validating the model's robustness and showing the potentiality of its application.European Union's Horizon 2020 research and innovation programme under grant agreement No 691287Ministerio de Economía, Industria y Competitividad (Project FJCI-2016-28833

Dynamic Energy Return on Energy Investment (EROI) and material requirements in scenarios of global transition to renewable energies

Producción CientíficaA novel methodology is developed to dynamically assess the energy and material investments required over time to achieve the transition from fossil fuels to renewable energy sources in the electricity sector. The obtained results indicate that a fast transition achieving a 100% renewable electric system globally by 2060 consistent with the Green Growth narrative could decrease the EROI of the energy system from current ~12:1 to ~3:1 by the mid-century, stabilizing thereafter at ~5:1. These EROI levels are well below the thresholds identified in the literature required to sustain industrial complex societies. Moreover, this transition could drive a substantial re-materialization of the economy, exacerbating risk availability in the future for some minerals. Hence, the results obtained put into question the consistence and viability of the Green Growth narrative.Ministerio de Economía, Industria y Competitividad (Project no. FJCI-2016-28833)MEDEAS project, funded by the European Union’s Horizon 2020 research and innovation programme under grant agreement No 69128

Recent Approaches for the Manufacturing of Polymeric Cranial Prostheses by Incremental Sheet Forming

This paper presents recent research experiences developed with the aim of manufacturing cranial prostheses in polymeric sheet using Incremental Sheet Forming (ISF) technologies. With this purpose, different approaches have been carried out in Single-Point Incremental Forming (SPIF) and Two-Point Incremental Forming (TPIF) in order to produce customized cranial implants using different polymeric materials. In this context, this research work provides a methodology to design and manufacture polymer customized cranial prostheses using the ISF technologies starting from a patient’s computerized tomography (CT). The results demonstrate the potential of manufacturing polymeric cranial prostheses by ISF in terms of the high formability achievable and show the appropriate geometrical accuracy at affordable manufacturing costs provided by these processes.Ministerio de Economía y Competitividad DPI2015-64047-

Una nueva visión de la agricultura en Cuba: propuestas y una experiencia local

The article presents an approach to what was proposed in the V Report on Agriculture of the Center for Coexistence Studies (CEC-Cuba) and its application in the local project "La Isleña", highlighting the progress that can be achieved through citizen empowerment in the development of the agricultural sector.El artículo realiza un acercamiento de lo propuesto en el V Informe sobre agricultura del Centro de Estudios Convivencia (CEC-Cuba) y su aplicación en el proyecto local “La Isleña”, destacando el progreso que se puede lograr desde el empoderamiento ciudadano en el desarrollo del sector agrario

Content Delivery and Sharing in Federated Cloud Storage

Cloud-based storage is becoming a cost-effective solution for agencies, hospitals, government instances and scientific centers to deliver and share contents to/with a set of end-users. However, reliability, privacy and lack of control are the main problems that arise when contracting content delivery services with a single cloud storage provider. This paper presents the implementation of a storage system for content delivery and sharing in federated cloud storage networks. This system virtualizes the storage resources of a set of organizations as a single federated system, which is in charge of the content storage. The architecture includes a metadata management layer to keep the content delivery control in-house and a storage synchronization worker/monitor to keep the state of storage resources in the federation as well as to send contents near to the end-users. It also includes a redundancy layer based on a multi-threaded engine that enables the system to withstand failures in the federated network. We developed a prototype based on this scheme as a proof of concept. The experimental evaluation shows the benefits of building content delivery systems in federated cloud environments, in terms of performance, reliability and profitability of the storage space.The work presented in this paper has been partially supported by EU under the COST programme Action IC1305, Network for Sustainable Ultrascale Computing (NESUS)

Ludwig's angina and ketoacidosis as a first manifestation of diabetes mellitus

Ludwig?s angina is a serious and rapidly progressive infectious process that spreads through the floor of the mouth and neck. In this paper we present an infrequent case of a patient who suffered an odontogenic infection with poor response to the previous treatment, which evolved towards a Ludwig?s angina combined with ketoacidosis in the context of a diabetes mellitus not known before. According to the literature reviewed, this case report represents the first contribution of a Ludwig?s angina and ketoacidosis as an initial manifestation of a diabetes mellitus. The airway management, the antibiotic prescription and the surgical drainage allowed the healing of the patient without medical complications. Factors of co-morbidity like the diabetes mellitus together with focus tooth of infection may eventually turn into serious medical complications as the diabetic ketoacidosis and develop potentially lethal cervical infections

Evaluation of total alloplastic temporo-mandibular joint replacement with two different types of prostheses : a three-year prospective study

Temporo-Mandibular Joint (TMJ) replacement has been used clinically for years. The objective of this study was to evaluate outcomes achieved in patients with two different categories of TMJ prostheses. All patients who had a TMJ replacement (TMJR) implanted during the study period from 2006 through 2012 were included in this 3-year prospective study. All procedures were performed using the Biomet Microfixation TMJ Replacement System, and all involved replacing both the skull base component (glenoid fossa) and the mandibular condyle. Fifty-seven patients (38 females and 19 males), involving 75 TMJs with severe disease requiring reconstruction (39 unilateral, 18 bilateral) were operated on consecutively, and 68 stock prostheses and 7 custom-made prostheses were implanted. The mean age at surgery was 52.6±11.5 years in the stock group and 51.8±11.7 years in the custom-made group. In the stock group, after three years of TMJR, results showed a reduction in pain intensity from 6.4±1.4 to 1.6±1.2 (p<0.001), and an improvement in jaw opening from 2.7±0.9 cm to 4.2±0.7 cm (p<0.001). In the custom-made group, after three years of TMJR, results showed a reduction in pain intensity from 6.0±1.6 to 2.2±0.4 (p<0.001), and an improvement in jaw opening from 1.5±0.5 cm to 4.3±0.6 cm (p<0.001). No statistically significant differences between two groups were detected. The results of this three-year prospective study support the surgical placement of TMJ prostheses (stock prosthetic, and custom-made systems), and show that the approach is efficacious and safe, reduces pain, and improves maximum mouth opening movement, with few complications. As such, TMJR represents a viable technique and a stable long-term solution for cranio-mandibular reconstruction in patients with irreversible end-stage TMJ disease. Comparing stock and custom-made groups, no statistically significant differences were detected with respect to pain intensity reduction and maximum mouth opening improvement