Cartografía local de áreas quemadas empleando teledetección

Gajardo, J.; Mena, C.; Ormazábal Y. y Morales, Y. Centro de Geomática. Universidad de Talca. Casilla 747, Talca. Chile.Se realizó la cartografía de un incendio forestal, ocurrido en la localidad de San José de Mingre, comuna de San Javier, Región del Maule, durante la temporada 2003 - 2004. El estudio empleó una serie de índices, transformaciones y métodos multipaso, efectuados sobre datos de una imagen del sensor TM a bordo de la plataforma Landsat. En una primera fase, la metodología empleada incluyó las correcciones geométricas, radiométricas y atmosféricas de la imagen satelital para obtener medidas de reflectancia. Posteriormente, se calcularon índices (NDVI, BAI), y la transformación (ALME). Se discriminaron de forma muy clara las zonas que se encontraban quemadas para la extracción de pixels semillas, posteriormente se analizó la separabilidad espectral de cada banda. En una segunda fase, se emplearon los pixels semillas para introducirlos en el algoritmo de crecimiento que permitió cartografiar el incendio. La información (combustible quemado, fecha del siniestro, recursos empleados), así como las mediciones reales de la superficie y perímetro del incendio fueron proporcionadas por CONAF Región del Maule. Sobre estas mediciones se contrastaron los resultados obtenidos en el procesamiento de la imagen Landsat. Los resultados indican una fiabilidad global que oscila entre 70 y 95% para las diversas técnicas empleadas, con una amplia variedad entre los índices espectrales y el crecimiento de regiones. Las conclusiones muestran que es factible emplear métodos de cuantificación de área quemada basados en datos remotos, demostrando su utilidad en casos de incendios de gran magnitud y de difícil acceso en donde es inviabl

Índices de área verde y cobertura vegetal para la ciudade de Parral (Chile), mediante Fotointerpretación y GIS

Mena, C (reprint author), Univ Talca, Fac Cs Forestales, Avda Lircay S-N, Talca, Chile.he importance of the green areas is increasing since they are an important factor in the health and welfare of urban population. Therefore, in Parral city, in Central Chile, it was quantified and analyzed the availability of green areas and vegetation cover, using aerial photographs scale 1: 10000 and Geographic Information Systems (GIS). In a first stage, urban street trees were quantified through a simple random sample of twenty-four units with field measurements combined with measurements on aerial photographs, from which it was obtained the surface provided. Subsequently, through the creation of GIS layers, the surface of existing green areas and available open spaces were obtained. In addition, through supervised digital classification, the surface covered by urban forestry in private spaces was calculated. Quantity indexes show that Parral city currently has 12.72 ha of green areas, equivalent to 4.82 m(2)/hab, which implies a green area frequency of 0.022 m(2)/m(2). These values could be improved, if the available open space are incorporated and thereby reach 12.06 m(2) per inhabitant. In relation with availability indexes it was established that the average of accessibility to a green area is 327.2 m. Moreover, assuming a buffer of 200 m around the green areas, it was determined that there are 5160 houses with the basic service (56.4%). By incorporating the available open spaces, these values decrease significantly obtaining an average of accessibility to a green area of 213.7 m and coverage of basic service of 79.2%. Finally, it was estimated that the existing vegetation within the urban blocks (urban forest in private spaces) represents an important resource 17.8 times larger than urban street trees, so it should be considered within the municipal plans and policies

The Relation Between Equity Incentives and Misreporting: The Role of Risk-Taking Incentives

Prior research argues that a manager whose wealth is more sensitive to changes in the firm׳s stock price has a greater incentive to misreport. However, if the manager is risk-averse and misreporting increases both equity values and equity risk, the sensitivity of the manager׳s wealth to changes in stock price (portfolio delta) will have two countervailing incentive effects: a positive “reward effect” and a negative “risk effect.” In contrast, the sensitivity of the manager׳s wealth to changes in risk (portfolio vega) will have an unambiguously positive incentive effect. We show that jointly considering the incentive effects of both portfolio delta and portfolio vega substantially alters inferences reported in prior literature. Using both regression and matching designs, and measuring misreporting using discretionary accruals, restatements, and enforcement actions, we find strong evidence of a positive relation between vega and misreporting and that the incentives provided by vega subsume those of delta. Collectively, our results suggest that equity portfolios provide managers with incentives to misreport when they make managers less averse to equity risk

Evaluation of CSF neurotransmitters and folate in 25 patients with Rett disorder and effects of treatment

Background: Rett disorder (RD) is a progressive neurodevelopmental entity caused by mutations in the MECP2 gene. It has been postulated that there are alterations in the levels of certain neurotransmitters and folate in the pathogenesis of this disease. Here we re-evaluated this hypothesis. Patients and methods: We evaluated CSF folate, biogenic amines and pterines in 25 RD patients. Treatment with oral folinic acid was started in those cases with low folate. Patients were clinically evaluated and videotaped up to 6 months after therapy. Results: CSF folate was below the reference values in 32% of the patients. Six months after treatment no clinical improvement was observed. Three of the four patients with the R294X mutation had increased levels of a dopamine metabolite associated to a particular phenotype. Three patients had low levels of a serotonin metabolite. Two of them were treated with fluoxetine and one showed clinical improvement. No association was observed between CSF folate and these metabolites, after adjusting for the patients age and neopterin levels. Conclusion: Our results support that folinic acid supplementation has no significant effects on the course of the disease. We report discrete and novel neurotransmitter abnormalities that may contribute to the pathogenesis of RD highlighting the need for further studies on CSF neurotransmitters in clinically and genetically well characterized patients.Research in Rett syndrome is supported by FSE/FEDER and Fundação para a Ciência e Tecnologia (FCT, Portugal), Grant No. POCTI 41416/2001

An Overview of the Circular Economy among SMEs in the Basque Country: A Multiple Case Study.

Purpose: This research analyzes the maturity of environmental management as well as the degreeof to which the Circular Economy has been implemented in Basque SMEs.Design/methodology/approach:A total of 17 case studies were carried out in industrialSMEs companies in the Basque Country.Findings:The main results show that companies are limited to complying with the law and inmany cases are worried about the image of the company, although they are not committed toenvironmental issues. There is still a lot to do in SMEs, as they are the companies that face thebiggest challenges due to a lack of resources.Originality/value: Circular Economy aims to change a linear economy into promotingsustainability of the economy while also engaging in sustainable environmental protection. Thisresearch has focused on small and medium enterprises as they represent a 99% of companies inEurope and they are the ones that have the most difficulty reaching a stage of environmentalexcellence due to their limited resources

MQLV: Optimal Policy of Money Management in Retail Banking with Q-Learning

Reinforcement learning has become one of the best approach to train a computer game emulator capable of human level performance. In a reinforcement learning approach, an optimal value function is learned across a set of actions, or decisions, that leads to a set of states giving different rewards, with the objective to maximize the overall reward. A policy assigns to each state-action pairs an expected return. We call an optimal policy a policy for which the value function is optimal. QLBS, Q-Learner in the Black-Scholes(-Merton) Worlds, applies the reinforcement learning concepts, and noticeably, the popular Q-learning algorithm, to the financial stochastic model of Black, Scholes and Merton. It is, however, specifically optimized for the geometric Brownian motion and the vanilla options. Its range of application is, therefore, limited to vanilla option pricing within the financial markets. We propose MQLV, Modified Q-Learner for the Vasicek model, a new reinforcement learning approach that determines the optimal policy of money management based on the aggregated financial transactions of the clients. It unlocks new frontiers to establish personalized credit card limits or bank loan applications, targeting the retail banking industry. MQLV extends the simulation to mean reverting stochastic diffusion processes and it uses a digital function, a Heaviside step function expressed in its discrete form, to estimate the probability of a future event such as a payment default. In our experiments, we first show the similarities between a set of historical financial transactions and Vasicek generated transactions and, then, we underline the potential of MQLV on generated Monte Carlo simulations. Finally, MQLV is the first Q-learning Vasicek-based methodology addressing transparent decision making processes in retail banking

Visualization of AE's Training on Credit Card Transactions with Persistent Homology

Auto-encoders are among the most popular neural network architecture for dimension reduction. They are composed of two parts: the encoder which maps the model distribution to a latent manifold and the decoder which maps the latent manifold to a reconstructed distribution. However, auto-encoders are known to provoke chaotically scattered data distribution in the latent manifold resulting in an incomplete reconstructed distribution. Current distance measures fail to detect this problem because they are not able to acknowledge the shape of the data manifolds, i.e. their topological features, and the scale at which the manifolds should be analyzed. We propose Persistent Homology for Wasserstein Auto-Encoders, called PHom-WAE, a new methodology to assess and measure the data distribution of a generative model. PHom-WAE minimizes the Wasserstein distance between the true distribution and the reconstructed distribution and uses persistent homology, the study of the topological features of a space at different spatial resolutions, to compare the nature of the latent manifold and the reconstructed distribution. Our experiments underline the potential of persistent homology for Wasserstein Auto-Encoders in comparison to Variational Auto-Encoders, another type of generative model. The experiments are conducted on a real-world data set particularly challenging for traditional distance measures and auto-encoders. PHom-WAE is the first methodology to propose a topological distance measure, the bottleneck distance, for Wasserstein Auto-Encoders used to compare decoded samples of high quality in the context of credit card transactions

Mutations in the urocanase gene UROC1 are associated with urocanic aciduria

[EN] Urocanase is an enzyme in the histidine pathway encoded by the UROC1 gene. This report describes the first putative mutations, p. L70P and p.R450C, in the coding region of the UROC1 gene in a girl with urocanic aciduria presenting with mental retardation and intermittent ataxia. Computed (in silico) predictions, protein expression studies and enzyme activity assays suggest that none of the mutations can produce a fully functional enzyme. The p. L70P substitution, which probably implies the disruption of an alpha-helix in the N-terminus, would alter its properties and therefore, its function. The p.R450C change would render impossible any interaction between urocanase and its substrate and would loss its enzyme activity. Consequently, these studies suggest that both mutations could alter the correct activity of urocanase, which would explain the clinical and biochemical findings described in this patient.We are grateful to the patient for her kind collaboration. We are indebted to Dr C Marco-Marín for the in silico structural studies. CIBERER is an initiative of the Instituto de Salud Carlos III. This work was supported by grants from the Fondo de Investigación Sanitaria (PI051318 and PI070548).Espinós-Armero, CÁ.; Pineda, M.; Martínez-Rubio, D.; Aída Ormazabal; María Antonia Vilaseca; Leo J. M. Spaapen; Palau, F.... (2009). Mutations in the urocanase gene UROC1 are associated with urocanic aciduria. Journal of Medical Genetics. 46(6):407-411. https://doi.org/10.1136/jmg.2008.06063240741146

Genotypic and phenotypic spectrum of pyridoxine-dependent epilepsy (ALDH7A1 deficiency)

Pyridoxine-dependent epilepsy was recently shown to be due to mutations in the ALDH7A1 gene, which encodes antiquitin, an enzyme that catalyses the nicotinamide adenine dinucleotide-dependent dehydrogenation of L-{alpha}-aminoadipic semialdehyde/L-{Delta}1-piperideine 6-carboxylate. However, whilst this is a highly treatable disorder, there is general uncertainty about when to consider this diagnosis and how to test for it. This study aimed to evaluate the use of measurement of urine L-{alpha}-aminoadipic semialdehyde/creatinine ratio and mutation analysis of ALDH7A1 (antiquitin) in investigation of patients with suspected or clinically proven pyridoxine-dependent epilepsy and to characterize further the phenotypic spectrum of antiquitin deficiency. Urinary L-{alpha}-aminoadipic semialdehyde concentration was determined by liquid chromatography tandem mass spectrometry. When this was above the normal range, DNA sequencing of the ALDH7A1 gene was performed. Clinicians were asked to complete questionnaires on clinical, biochemical, magnetic resonance imaging and electroencephalography features of patients. The clinical spectrum of antiquitin deficiency extended from ventriculomegaly detected on foetal ultrasound, through abnormal foetal movements and a multisystem neonatal disorder, to the onset of seizures and autistic features after the first year of life. Our relatively large series suggested that clinical diagnosis of pyridoxine dependent epilepsy can be challenging because: (i) there may be some response to antiepileptic drugs; (ii) in infants with multisystem pathology, the response to pyridoxine may not be instant and obvious; and (iii) structural brain abnormalities may co-exist and be considered sufficient cause of epilepsy, whereas the fits may be a consequence of antiquitin deficiency and are then responsive to pyridoxine. These findings support the use of biochemical and DNA tests for antiquitin deficiency and a clinical trial of pyridoxine in infants and children with epilepsy across a broad range of clinical scenarios