Pricing renewable energy certificates with a Crank–Nicolson Lagrange–Galerkin numerical method

Financiado para publicación en acceso aberto: Universidade da Coruña/CISUG[Abstract]: The valuation problem of renewable energy certificates can be formulated in terms of a nonlinear PDE model where the underlying stochastic factors are the accumulated green certificates sold by an authorized producer and the natural logarithm of the renewable generation rate. In the present paper, the nonlinear convective term is treated with the Bermúdez–Moreno duality method for maximal monotone operators as in Baamonde-Seoane et al. (2021). The main novelty of this article comes from the proposed techniques for the numerical solution of the resulting linear problem. In this case, we propose a Lagrange–Galerkin method which mainly consists of Crank–Nicolson characteristics for time discretization combined with finite elements for the discretization in the accumulated green certificates and the natural logarithm of the renewable generation rate directions. Finally, several numerical examples are presented to illustrate the good performance of the method and model, and its comparison with other numerical schemes employed to solve the same problem.Xunta de Galicia; ED431C 2018/033Xunta de Galicia; ED431C 2022/47Xunta de Galicia; ED431G 2019/01The authors acknowledge the funding by Spanish MINECO with the grants MTM2016-76497-R and PID2019-10858RB-I00, and by Galician Government, Spain with the grants ED431C 2018/033 and ED431C 2022/47, both including FEDER financial support. As members of CITIC, they also acknowledge the grant ED431G 2019/01, funded by Consellería de Educación, Spain , Universidade e Formación Profesional of Xunta de Galicia through FEDER funds with 80%, from FEDER Galicia 2014–2020 Program and 20% from Secretaría Xeral de Universidades

Model and numerical methods for pricing renewable energy certificate derivatives

[Abstract]: Assuming that the price of the renewable energy certificate (REC) is known, we formulate the valuation problem of a European REC derivative in terms of a linear PDE model where the underlying stochastic factors are the accumulated green certificates sold by an authorized producer and the natural logarithm of the renewable generation rate. Next, a result of existence of solution is obtained for this PDE problem. In order to solve numerically the PDE problem, we propose two different methods: a semi-Lagrangian scheme in time combined with finite differences discretizations in the spatial-like variables, or alternative Lagrange–Galerkin methods. The application to the pricing of European options and futures on renewable energy certificates is addressed. Finally, we show illustrative results about the performance of the models and numerical methods that have been implemented.Xunta de Galicia; ED431C 2018/033Xunta de Galicia; ED431C 2022/047Xunta de Galicia; ED431G 2019/01This work has been funded by MICINN from Spain (Grant PID2019-10858RB-I00), and by Xunta of Galicia (Grant ED431C 2018/033 and ED431C 2022/047), all including FEDER financial co-funding. All authors are members of CITIC, so that they acknowledge grant ED431G 2019/01, funded by Consellería de Educación, Universidade e Formación Profesional of Xunta de Galicia through FEDER, Spain funds with 80%, from FEDER Galicia 2014–2020 Program and 20% from Secretaría Xeral de Universidades. Funding for open access charge: Universidade da Coruña/CISUG. Authors are also grateful to two anonymous reviewers whose remarks helped to improve the article

Three-year follow-up of posterior chamber phakic intraocular lens with a central port design after deep anterior lamellar keratoplasty

Background: To evaluate clinical outcomes of the Visian implantable collamer lens (ICL) with a central port to correct myopia and astigmatism after deep anterior lamellar keratoplasty (DALK) for keratoconus throughout 3 years of follow-up. Methods: This study included 20 eyes of 20 patients that underwent V4c ICL (13 eyes with a spherical ICL and 7 eyes with a toric ICL) implantation after DALK. Uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, intraocular pressure (IOP), endothelial cell density (ECD), and vault were analyzed. Results: The mean UDVA improved from the preoperative 1.18 ± 0.33 logMAR to 0.25 ± 0.14 logMAR at 6 months after surgery (P < 0.0001) and remained unchanged throughout the whole follow-up (P = 0.4). All eyes gained lines of CDVA compared to preoperative values. At the last follow-up visit, all eyes achieved CDVA of 0.2 logMAR or better and 13 eyes (65%) 0.1 logMAR or better. At 6 months post-surgery, all eyes (100%) had a spherical equivalent within ± 1.50 D, and 19 (95%) within ± 1.00 D. The mean manifest spherical equivalent was stable over the postoperative follow-up (P = 0.25). No significant increase in IOP occurred in any case throughout the 3 years of follow-up. The loss in ECD from the preoperative baseline at the last follow-up visit was 2.27%. Conclusions: The clinical outcomes suggest that the V4c ICL implantation for correction of myopia and regular astigmatism in post-DALK eyes was satisfactory in terms of effectiveness, safety, and stability during 3 years of follow-up.Depto. de Optometría y VisiónFac. de Óptica y OptometríaTRUESTAAR® Surgical (Estados Unidos)pu

Airway Complications after Lung Transplantation—A Contemporary Series of 400 Bronchial Anastomoses from a Single Center

(1) Objective: To determine whether recent advances in lung transplantation (LT) have reduced the incidence and changed the risk factors for airway complications (AC). (2) Methods: Retrospective analysis of patients receiving a lung transplant between January 2007 and January 2019. An AC was defined as a bronchoscopic abnormality in the airway, either requiring or not requiring an endoscopic or surgical intervention. Both univariable and multivariable analyses were performed to identify risk factors for AC. (3) Results: 285 lung transplants (170 single and 115 bilateral lung transplants) were analysed, comprising 400 anastomoses at risk. A total of 50 anastomoses resulted in AC (12%). There were 14 anastomotic and 11 non-anastomotic stenoses, 4 dehiscences, and 3 malacias. Independent predictors for AC were: gender male (OR: 4.18; p = 0.002), cardiac comorbidities (OR: 2.74; p = 0.009), prolonged postoperative mechanical ventilation (OR: 2.5; p = 0.02), PaO2/FiO2 < 300 mmHg at 24 h post-LT (OR: 2.48; p = 0.01), graft infection (OR: 2.16; p = 0.05), and post-LT isolation of Aspergillus spp. (OR: 2.63; p = 0.03). (4) Conclusions: In spite of advances in lung transplantation practice, the risk factors, incidence, and lethality of AC after LT remains unchanged. Graft dysfunction, an infected environment, and the need of prolonged mechanical ventilation remain an Achilles heel for AC

Impact of a phone app on nephrology referral.

Various factors can lead to inadequate nephrology referral decisions being taken by clinicians, but a major cause is unawareness of guidelines, recommendations and indications, or of appropriate timing. Today, tools such as smartphone applications (Apps) can make this knowledge more accessible to non-nephrologist clinicians. Our study aim is to determine the effectiveness of a purpose-built app in this respect. In a retrospective study, nephrology referrals were compared before and after the introduction of the app in clinical practice. The initial study population consisted of first visits by patients referred to our department in 2015, before the introduction of the app. In 2016, the smartphone app NefroConsultor began to be implemented in our hospital. We compared the initial study population with the results obtained for patients referred in 2017, when the app was in use, taking into account clinical features considered, such as urinalysis, proteinuria or kidney ultrasound, to determine whether these patients met currently recommended criteria for referral. The total study population consisted of 628 patients, of whom 333 were examined before the introduction of the app (in 2015) and 295 when it was in use (in 2017). Among the first group, 132 (39.6%) met established KDIGO criteria for nephrology referral and were considered to be correctly referred. Among the second group, 200 (67.8%) met the criteria and were considered to be properly referred (P = 0.001). The increase in the rate of intervention success (before-after app) was 28.8% with a binomial effect size display (Cohen's d effect size) of 0.751. Before the introduction of the app, data for albuminuria were included in 62.5% of nephrology referrals; in 2017, the corresponding value was 87.5% (P = 0.001). In the same line, referrals including urinalysis rose from 68.5% to 85.8% (P = 0.001). Multivariate regression analysis, using referrals meeting KDIGO criteria as the dependent variable and adjusting for age, sex and referring department, showed that the 2017 group (after the introduction of NefroConsultor) was associated with an odds ratio of 3.57 (95% confidence interval 2.52-5.05) for correct referrals, compared with the 2015 group (P = 0.001). References to proteinuria as the reason for nephrology referral also increased from 23.7% to 34.2% (P = 0.004). Use of the app is associated with more frequent studies of albuminuria at the time of referral and a greater likelihood of proteinuria being cited as the reason for referral. The smartphone app considered can improve the accessibility of information concerning nephrology referrals and related studies

La enseñanza en el máster de abogacía a través del análisis de casos reales de carácter multidisciplinar. Aprendizaje "a partir del estudio de razonamientos parciales temáticos"

Generar blog para publicaciones de alumnos del Máster Abogacía, con "entradas" dirigidas. Habría análisis desde varias disciplinas añadiéndose estudios con enfoque basado en otras áreas de conocimiento, generando interdisciplinariedad

Artistas sobre outras obras

Este número da Revista Estúdio assinala a crescente maturação de um espaço de comunicação algo alternativo, onde artistas falam de artistas, dão a conhecer obras menos conhecidas, e ocupam uma área de curadoria expontânea e paralela aos centros do arte world. Dá-se a palavra aos próprios criadores, e há seis anos que o seu olhar vem enriquecendo um património crescente, com especiais ligações aos países onde se fala as línguas ibéricas. A presença de obras de Portugal, Espanha, Brasil, Angola, Argentina, Perú, Venezuela, Bolívia e muitos outros países tornou-se habitual, fazendo da Estúdio uma instância da semiosfera (Lotman). Mais do que a presença, é a dimensão do conhecimento transmitido, a que se segue, naturalmente, o estabelecimento de novas teias de referência entre os artistas destes países: há novos grupos, novas cumplicidades, novas realizações dentro deste Estúdio, que completa seis anos de publicação persistente. A Revista Estúdio é também mais uma via disponível para o exercício da interpretação, através de descodificações mais informadas, mais negociadas, dos textos artísticos, pois são efectuadas por outros artistas. Reuniram-se nesta edição 24 artigos originais, mantendo a sua linha editorial inicial. O projecto mantém a sua componente de resistência, de plataforma de conhecimento para os pares, não abdicando também da validação externa, ou seja, do uso de protocolos de produção e transmissão de conhecimento. Falamos pois das normas de redação, de referenciação, de estruturação de textos e de articulação de argumentos, visuais ou verbais. Estabelece-se neste volume uma articulação entre cinema, vídeo, redes, escultura, instalação, fotografia, performance, banda desenhada, pintura, cerâmica, poesia concreta, livros de artista, sendo este conjunto não exaustivo testemunha do grau de hibridação que hoje o discurso artístico convoca. Apanhando-lhe o pulso, a Estúdio acompanha a arte desde os seus produtores, dos seus procedimentos, dos seus recursos, dos seus resultados. A Estúdio permite visitar muitos estúdios.info:eu-repo/semantics/publishedVersio

Protective intraoperative ventilation with higher versus lower levels of positive end-expiratory pressure in obese patients (PROBESE): study protocol for a randomized controlled trial

Background: Postoperative pulmonary complications (PPCs) increase the morbidity and mortality of surgery in obese patients. High levels of positive end-expiratory pressure (PEEP) with lung recruitment maneuvers may improve intraoperative respiratory function, but they can also compromise hemodynamics, and the effects on PPCs are uncertain. We hypothesized that intraoperative mechanical ventilation using high PEEP with periodic recruitment maneuvers, as compared with low PEEP without recruitment maneuvers, prevents PPCs in obese patients. Methods/design The PRotective Ventilation with Higher versus Lower PEEP during General Anesthesia for Surgery in OBESE Patients (PROBESE) study is a multicenter, two-arm, international randomized controlled trial. In total, 2013 obese patients with body mass index ≥35 kg/m2 scheduled for at least 2 h of surgery under general anesthesia and at intermediate to high risk for PPCs will be included. Patients are ventilated intraoperatively with a low tidal volume of 7 ml/kg (predicted body weight) and randomly assigned to PEEP of 12 cmH2O with lung recruitment maneuvers (high PEEP) or PEEP of 4 cmH2O without recruitment maneuvers (low PEEP). The occurrence of PPCs will be recorded as collapsed composite of single adverse pulmonary events and represents the primary endpoint. Discussion To our knowledge, the PROBESE trial is the first multicenter, international randomized controlled trial to compare the effects of two different levels of intraoperative PEEP during protective low tidal volume ventilation on PPCs in obese patients. The results of the PROBESE trial will support anesthesiologists in their decision to choose a certain PEEP level during general anesthesia for surgery in obese patients in an attempt to prevent PPCs. Trial registration ClinicalTrials.gov identifier: NCT02148692. Registered on 23 May 2014; last updated 7 June 2016. Electronic supplementary material The online version of this article (doi:10.1186/s13063-017-1929-0) contains supplementary material, which is available to authorized users

Method for Pricing Renewable Energy Certificates

Cursos e Congresos, C-155[Abstract] In this work we present one valuation method for Renewable Energy Certificates (RECs). Starting from a system of FBSDEs and using Ito lemma, we propose a mathematical model based on a semilinear PDE with two stochastic factors. The main novelty comes from the use of the Bermúdez-Moreno algorithm to deal the non-linear convective term in the PDE. This duality algorithm is based on the Yosida regularization of non-linear maximal monotone operators. The resulting linear problem is discretized by using a characteristics method combined with a second order implicit finite differences scheme. We showillustrative results of the performance of the proposed model and the numerical methodCITIC is funded by the Xunta de Galicia through the collaboration agreement between the Consellería de Cultura, Educación, Formación Profesional e Universidades and the Galician universities for the reinforcement of the research centres of the Galician University System (CIGUS

Profile of Subclinical Psychopathy in Spanish University Students

Psychopaths are portrayed as deceitful, manipulative, domineering and narcissistic; the result of an irregular and irresponsible interpersonal style that harms both the psychopath him/herself and others. Furthermore, psychopathy is frequently associated with both violent and antisocial conduct. However, subclinical psychopaths are known for manifesting this type of profile without committing crimes. The objective of this study is to examine the differences that exist in subclinical psychopathy concerning gender, the number of intimate relationships and the age of the university student. The number of university students participating was 1289. They were given the Integrated/Subclinical Psychopathy Questionnaire (CUPIS). The results show that, in subclinical psychopathy, men present higher scores than women and younger persons have higher scores than older persons. In addition, the scores in psychopathy are higher for students who have had a larger number of intimate relationships. The contributions of this study allow us to determine the profile associated with subclinical psychopathy