Extending Modelling Activity Diagrams as a tool to characterise mathematical modelling processes

In this paper, we present a qualitative study in which we analyse the videorecordings of four groups of students solving Fermi Problems. Previous studies show that Secondary School students solve this type of problems using complex problem solving processes and developing mathematical models. In order to analyse the students’ problem solving processes, so-called Modelling Activity Diagrams were used. The results of the present study demonstrate that solving Fermi problems is a complex matter, and that some of the theoretical tools used in the field of Mathematical Education fail to adequately reflect this level of complexity. In addition, Modelling Activity Diagrams are presented as a more detailed analysis tool to characterise student choices and actions, as well as to make the structure of the Fermi problem addressed more visible

Bacterial lipopolysaccharide induces apoptosis in the trout ovary

BACKGROUND: In mammals it is well known that infections can lead to alterations in reproductive function. As part of the innate immune response, a number of cytokines and other immune factors is produced during bacterial infection or after treatment with lipopolysaccharide (LPS) and acts on the reproductive system. In fish, LPS can also induce an innate immune response but little is known about the activation of the immune system by LPS on reproduction in fish. Therefore, we conducted studies to examine the in vivo and in vitro effects of lipopolysaccharide (LPS) on the reproductive function of sexually mature female trout. METHODS: In saline- and LPS -injected brook trout, we measured the concentration of plasma steroids as well as the in vitro steroidogenic response (testosterone and 17alpha-hydroxyprogesterone) of ovarian follicles to luteinizing hormone (LH), the ability of 17alpha,20beta-dihydroxy-4-pregnen-3-one to induce germinal vesicle breakdown (GVBD) in vitro, and that of epinephrine to stimulate follicular contraction in vitro. We also examined the direct effects of LPS in vitro on steroid production, GVBD and contraction in brook trout ovarian follicles. The incidence of apoptosis was evaluated by TUNEL analysis. Furthermore, we examined the gene expression pattern in the ovary of saline- and LPS-injected rainbow trout by microarray analysis. RESULTS: LPS treatment in vivo did not affect plasma testosterone concentration or the basal in vitro production of steroids, although a small but significant potentiation of the effects of LH on testosterone production in vitro was observed in ovarian follicles from LPS-treated fish. In addition, LPS increased the plasma concentration of cortisol. LPS treatment in vitro did not affect the basal or LH-stimulated steroid production in brook trout ovarian follicles. In addition, we did not observe any effects of LPS in vivo or in vitro on GVBD or follicular contraction. Therefore, LPS did not appear to impair ovarian steroid production, oocyte final maturation or follicular contraction under the present experimental conditions. Interestingly, LPS administration in vivo induced apoptosis in follicular cells, an observation that correlated with changes in the expression of genes involved in apoptosis, as evidenced by microarray analysis. CONCLUSION: These results indicate that female trout are particularly resistant to an acute administration of LPS in terms of ovarian hormone responsiveness. However, LPS caused a marked increase in apoptosis in follicular cells, suggesting that the trout ovary could be sensitive to the pro-apoptotic effects of LPS-induced inflammatory cytokines

El encuentro del tejido urbano con el mar: límite, borde o interacción

El trabajo que se presenta sostiene la tesis de que la relación entre la ciudad y el mar ha ido evolucionándo desde un planteamiento de límite o final del tejido urbano que se contrapone a un paisaje natural, y que por tanto suponía un acusado desencuentro entre ambos, hacia la búsqueda de mecanismos que propicien la interacción y continuidad entre artificio y naturaleza, consiguiéndose una nueva lectura de esa relación.Esta evolución se considera claramente positiva al pasar de un planteamiento invasivo de la ciudad sobre el espacio natural modificando su ecosistema, a un diálogo transversal, de forma que la ciudad y la naturaleza, en este caso el mar, se complementen estableciendo una integración secuenciada, de forma que el tejido urbano se diluya como si de una mancha de aceite se tratara. Ello está suponiendo la regeneración de los ecosistemas perdidos a la vez que una nueva mirada de la sociedad hacia la naturaleza, teniendo mucha mas conciencia de su alto valor ecológico.Se han analizado cerca de veinte casos de diferentes partes del mundo, reconociendo muy diversas formas de establecer esta relación, siendo el concepto de “paseo marítimo“ la  clave fundamental que la define.Tiene interés el reconocimiento de las diferentes herramientas paisajísticas que se han empleado en la definición de los recorridos, tensiones, flujos, secuencia de espacios, …. así como las que permiten resaltar las diferentes miradas: desde el mar, desde la ciudad, visión parcial o de conjunto, intensa o contemplativa, veloz o reposada, …Bosch Reig, I.; Bosch Roig, L.; Marcenac, V.; Salvador Luján, N. (2020). El encuentro del tejido urbano con el mar: límite, borde o interacción. En III Congreso Internacional ISUF-H. CIUDAD COMPACTA VS. CIUDAD DIFUSA. Editorial Universitat Politècnica de València. (20-05-2020):1-7. https://doi.org/10.4995/ISUFh2019.2019.10006OCS1720-05-202

Validation of a new tool to assess health-related quality of life in psoriasis: the PSO-LIFE questionnaire

BACKGROUND: Several questionnaires have been used to measure health related quality of life (HRQoL) in patients with psoriasis, few have been adapted for use in Spain; none of them was developed specifically for the Spanish population. The purpose of the study was to validate and assess the sensitivity to change of a new questionnaire to measure HRQOL in patients with psoriasis (PSO-LIFE). METHODS: Observational, prospective, multicenter study performed in centers around Spain. Patients with active or inactive psoriasis completed the PSO-LIFE together with other Dermatology Quality of Life Index (DLQI) and Psoriasis Disability Index (PDI). A control group of patients with urticaria or atopic dermatitis was also included. Internal consistency and test-retest reliability of the PSO-LIFE were assessed by calculating Cronbach’s alpha and Intraclass Correlation Coefficient (ICC). Validity was assessed by examining factorial structure, the capacity to discriminate between groups, and correlations with other measures. Sensitivity to change was measured using effect sizes. RESULTS: The final sample included for analysis consisted of 304 patients and 56 controls. Mean (SD) age of psoriasis patients was 45.3 (14.5) years compared to 38.8 (14) years for controls (p < 0.01). Cronbach’s alpha for the PSO-LIFE was 0.95 and test-retest reliability using the ICC was 0.98. Factor analysis showed the questionnaire to be unidimensional. Mean (SD) PSO-LIFE scores differed between patients with psoriasis and controls (64.9 [22.5] vs 69.4 [17.3]; p < 0.05), between those with active and inactive disease (57.4 [20.4] vs 76.4 [20.6]; p < 0.01), and between those with visible and non-visible lesions (63.0 [21.9] vs. 74.8 [23.9]; p < 0.01). The correlation between PSO-LIFE and PASI scores was moderate (r = −0.43) while correlations with DLQI and PDI dimensions ranged from moderate to high (between 0.4 and 0.8). Effect size on the PSO-LIFE in patients reporting ‘much improved’ health status at study completion was 1.01 (large effect size). CONCLUSIONS: The present results provide substantial support for the reliability, validity, and responsiveness of the PSO-LIFE questionnaire in the population for which it was designed

More future synergies and less trade-offs between forest ecosystem services with natural climate solutions instead of bioeconomy solutions

To reach the Paris Agreement, societies need to increase the global terrestrial carbon sink. There are many climate change mitigation solutions (CCMS) for forests, including increasing bioenergy, bioeconomy, and protection. Bioenergy and bioeconomy solutions use climate-smart, intensive management to generate high quantities of bioenergy and bioproducts. Protection of (semi-)natural forests is a major component of "natural climate solution" (NCS) since forests store carbon in standing biomass and soil. Furthermore, protected forests provide more habitat for biodiversity and non-wood ecosystem services (ES). We investigated the impacts of different CCMS and climate scenarios, jointly or in isolation, on future wood ES, non-wood ES, and regulating ES for a major wood provider for the international market. Specifically, we projected future ES given by three CCMS scenarios for Sweden 2020-2100. In the long term, fulfilling the increasing wood demand through bioenergy and bioeconomy solutions will decrease ES multifunctionality, but the increased stand age and wood stocks induced by rising greenhouse gas (GHG) concentrations will partially offset these negative effects. Adopting bioenergy and bioeconomy solutions will have a greater negative impact on ES supply than adopting NCS. Bioenergy or bioeconomy solutions, as well as increasing GHG emissions, will reduce synergies and increase trade-offs in ES. NCS, by contrast, increases the supply of multiple ES in synergy, even transforming current ES trade-offs into future synergies. Moreover, NCS can be considered an adaptation measure to offset negative climate change effects on the future supplies of non-wood ES. In boreal countries around the world, forestry strategies that integrate NCS more deeply are crucial to ensure a synergistic supply of multiple ES

Hypoalbuminemia and advanced age are risk factors for delayed gastric emptying after pancreaticoduodenectomy

Background:delayed gastric emptying (DGE) is one of the most common complications after pancreatoduodenectomy. It could be related to some baseline patient-related characteristics. This study aims to assess the predictive factors associated to DGE in the cohort of patients included in the PAUDA clinical trial. Methods:this study was a retrospective analysis based on the 80 patients included in a randomized clinical trial conducted and published by our group. A descriptive analysis and a bivariate regression model were carried out. Some factors were further scrutinized for associations using the Pearson correlation coefficient and, finally, a multiple regression model using a stepwise selection of variables was conducted. Results:DGE was diagnosed in 36 (45 %) out of 80 patients (DGE group). The number of patients older than 60 years old in the DGE group was greater than in the group without DGE (32 vs 28 patients, p = 0.009]). Likewise, the number of patients with a preoperative albumin 200 & mu;mol/L (14 vs 8 patients, p = 0.039); postoperative haemorrhage (7 vs 1 patients, p = 0.011); postoperative intraabdominal abscess (12 vs 5 patients, p = 0.017); and postoperative biliary fistula (5 vs 0 patients, p = 0.011), was also greater in the DGE group. Two risk factors were associated with DGE: the patient's age at the time of surgery and preoperative hypoalbuminemia (serum albumin concentration & LE; 35g/L). Conclusions:the patient's age at the time of surgery and the preoperative nutritional status are independent risk factors to the development of DGE after pancreatoduodenectomy

Analysis of Mathematical Models Produced when Solving Fermi Problems

[EN] In this paper, we present an analysis of written productions of 16 year-old students while solving Estimation Problems involving Big Numbers (EPiBN). This kind of problems is a particular type of Fermi problems and allows us to introduce modelling processes in Secondary school classrooms. Our analysis supports on the characterization of mathematical models developed by students based on the model definition of Lesh and Harel. The results show that, through the analysis of EPiBN resolutions, differentiating aspects can be distinguished between the models produced by students without modelling experience of those produced by students with prior experience, especially in the concepts and language used to shape the built mathematical models.[ES] En este trabajo presentamos un estudio en el que analizamos las producciones escritas de estudiantes de 16 años con diferentes niveles de experiencia en modelización al resolver Problemas de Estimación de Grandes Cantidades (PEGC). Estos problemas son un tipo concreto de los Problemas de Fermi y permiten introducir los procesos de modelización en las aulas de Educación Secundaria. Nuestro análisis se soporta en la caracterización de los modelos matemáticos que producen los alumnos, basada en la definición de modelo matemático propuesta por Lesh y Harel. Los resultados muestran que, a través del análisis de las resoluciones de PEGC, se pueden distinguir aspectos diferenciadores entre los modelos producidos por alumnos sin experiencia modelizadora de aquellos producidos por alumnos con experiencia previa, especialmente en los conceptos y lenguajes utilizados para dar forma a los modelos matemáticos construidos.Este trabajo es fruto de una investigación llevada a cabo en el marco de los proyectos de investigación EDU2012-35638 y EDU2013-4683-R que han recibido soporte económico del Ministerio de Economía y Competitividad español y de los Fondos FEDER, así como de la ayuda recibida por parte de la Conselleria de Educació de la Generalitat Valenciana (proyecto GV/2016/129) y la Direcció General de Recerca de la Generalitat de Catalunya (SGR2014-723).Ferrando Palomares, I.; Albarracín, L.; Gallart-Palau, C.; García-Raffi, LM.; Gorgorió, N. (2017). Análisis de los Modelos Matemáticos Producidos durante la Resolución de Problemas de Fermi. Bolema. 31(57):220-242. https://doi.org/10.1590/1980-4415v31n57a11S2202423157Albarracín, L., & Gorgorió, N. (2013). PROBLEMAS DE ESTIMACIÓN DE GRANDES CANTIDADES: MODELIZACIÓN E INFLUENCIA DEL CONTEXTO. Revista Latinoamericana de Investigación en Matemática Educativa, 16(3), 289-315. doi:10.12802/relime.13.1631Albarracín, L., & Gorgorió, N. (2014). Devising a plan to solve Fermi problems involving large numbers. Educational Studies in Mathematics, 86(1), 79-96. doi:10.1007/s10649-013-9528-9Blum, W. (2002). Educational Studies in Mathematics, 51(1/2), 149-171. doi:10.1023/a:1022435827400Ferri, R. B. (2006). Theoretical and empirical differentiations of phases in the modelling process. ZDM, 38(2), 86-95. doi:10.1007/bf02655883Carlson, J. E. (1997). Fermi problems on gasoline consumption. The Physics Teacher, 35(5), 308-309. doi:10.1119/1.2344696Efthimiou, C. J., & Llewellyn, R. A. (2007). Cinema, Fermi problems and general education. Physics Education, 42(3), 253-261. doi:10.1088/0031-9120/42/3/003Lesh, R., & Harel, G. (2003). Problem Solving, Modeling, and Local Conceptual Development. Mathematical Thinking and Learning, 5(2), 157-189. doi:10.1207/s15327833mtl0502&3_03Lester, F. K. (1994). Musings about Mathematical Problem-Solving Research: 1970-1994. Journal for Research in Mathematics Education, 25(6), 660. doi:10.2307/749578Schoenfeld, A. H. (2007). Problem solving in the United States, 1970–2008: research and theory, practice and politics. ZDM, 39(5-6), 537-551. doi:10.1007/s11858-007-0038-zCampos, I. da S., & Araújo, J. de L. (2015). Envolvimento dos Alunos em Atividades de Modelagem Matemática: relação com o saber e possibilidades de ação. Bolema: Boletim de Educação Matemática, 29(51), 167-182. doi:10.1590/1980-4415v29n51a09Sriraman, B., & Knott, L. (2009). The Mathematics of Estimation: Possibilities for Interdisciplinary Pedagogy and Social Consciousness. Interchange, 40(2), 205-223. doi:10.1007/s10780-009-9090-

Incorporating fire-smartness into agricultural policies reduces suppression costs and ecosystem services damages from wildfires

In southern Europe, land abandonment and an unbalanced investment toward fire suppression instead of prevention has gradually increased wildfire risk, which calls for a paradigm change in fire management policies. Here we combined scenario analysis, fire landscape modelling, and economic tools to identify which land-use policies would reduce the expected wildfire-related losses in the Transboundary Biosphere Reserve ‘Gerês-Xurés’ (Spain-Portugal). To do so, we applied the least-cost-plus-net-value-change approach and estimated net changes in wildfire damages based on their implications for the 2010-2050 period and five ecosystem services: agriculture, pasture, timber, recreation and climate regulation. Four land-use scenarios were considered: (1) Business as Usual (BAU); (2) fire-smart, fostering more fire-resistant (less flammable) and/or fire-resilient landscapes (fire-smart); (3) High Nature Value farmlands (HNVf), wherein the abandonment of extensive agriculture is reversed; and (4) a combination of HNVf and fire-smart. HNVf is the best scenario for suppression cost savings, but it generates the lowest net present value of societal benefits from climate regulation. In fact, the most efficient scenario with the lowest societal discounted net suppression costs and change on ecosystem services damages is the HNVf + fire-smart scenario, as it also generates suppression cost savings from agricultural expansion, and lead to a significant reduction in damages on timber and recreational benefits. Therefore, reverting land abandonment through recultivation and promoting fire-resistant tree species is the most efficient way to reduce wildfire hazard. In this sense, payments for ecosystem services should reward farmers and landowners for their role in wildfire prevention. This study improves the understanding of the financial and societal benefits derived from reducing fire suppression spending and ecosystem services damage by undertaking fire-smart land-use strategies, which can be essential to enhance local stakeholders' support for Payments of Ecosystem Services policies for wildfire prevention

Prognostic value and risk stratification of residual disease in patients with incidental gallbladder cancer

Background and aim: given their poor prognosis, patients with residual disease (RD) in the re-resection specimen of an incidental gallbladder carcinoma (IGBC) could benefit from a better selection for surgical treatment. The Gallbladder Cancer Risk Score (GBRS) has been proposed to preoperatively identify RD risk more precisely than T-stage alone. The aim of this study was to assess the prognostic value of RD and to validate the GBRS in a retrospective series of patients. Material and methods: a prospectively collected database including 59 patients with IGBC diagnosed from December 1996 to November 2015 was retrospectively analyzed. Three locations of RD were established: local, regional, and distant. The effect of RD on overall survival (OS) was analyzed with the Kaplan-Meier method. To identify variables associated with the presence of RD, characteristics of patients with and without RD were compared using Fisher's exact test. The relative risk of RD associated with clinical and pathologic factors was studied with a univariate logistic regression analysis. Results: RD was found in 30 patients (50.8%). The presence of RD in any location was associated with worse OS (29% vs. 74.2%, p = 0.0001), even after an R0 resection (37.7% vs 74.2%, p = 0.003). There was no significant difference in survival between patients without RD and with local RD (74.2% vs 64.3%, p = 0.266), nor between patients with regional RD and distant RD (16.1% vs 20%, p = 0.411). After selecting patients in which R0 resection was achieved (n = 44), 5-year survival rate for patients without RD, local RD, and regional RD was, respectively, 74.2%, 75%, and 13.9% (p = 0.0001). The GBRS could be calculated in 25 cases (42.3%), and its usefulness to predict the presence of regional or distant RD (RDRD) was confirmed (80% in high-risk patients and 30% in intermediate risk p = 0.041). Conclusion: RDRD, but not local RD, represents a negative prognostic factor of OS. The GBRS was useful to preoperatively identify patients with high risk of RDRD. An R0 resection did not improve OS of patients with regional RD

MEN1-associated primary hyperparathyroidism in the Spanish Registry: Clinical characterictics and surgical outcomes

Primary hyperparathyroidism is the most frequent manifestation of multiple endocrine neoplasia type 1 (MEN1) syndrome. Bone and renal complications are common. Surgery is the treatment of choice, but the best timing for surgery is controversial and predictors of persistence and recurrence are not well known. Our study describes the clinical characteristics and the surgical outcomes, after surgery and in the long term, of the patients with MEN1 and primary hyperparathyroidism included in the Spanish Registry of Multiple Endocrine Neoplasia, Pheochromocytomas and Paragangliomas (REGMEN). Eighty-nine patients (49 men and 40 women, 34.2 ± 13 years old) were included. Sixtyfour out of the 89 underwent surgery: a total parathyroidectomy was done in 13 patients, a subtotal parathyroidectomy in 34 and a less than subtotal parathyroidectomy in 15. Remission rates were higher after a total or a subtotal parathyroidectomy than after a less than subtotal (3/4 and 20/22 vs 7/12, P < 0.05), without significant differences in permanent hypoparathyroidism (1/5, 9/23 and 0/11, N.S.). After a median follow-up of 111 months, 20 of the 41 operated patients with long-term follow-up had persistent or recurrent hyperparathyroidism. We did not find differences in disease-free survival rates between different techniques, patients with or without permanent hypopar athyroidism and patients with different mutated exons, but a second surgery was more freq uent after a less than subtotal parathyroidectomyThe Spanish Registry of Multiple Endocrine Neoplasia, Pheochromocytmas and Paragangliomas is supported by IPSEN Pharmaceutical