Machine learning methods applied to combined Raman and LIBS spectra: Implications for mineral discrimination in planetary missions

Producción CientíficaThe combined analysis of geological targets by complementary spectroscopic techniques could enhance the characterization of the mineral phases found on Mars. This is indeed the case with the SuperCam instrument onboard the Perseverance rover. In this framework, the present study seeks to evaluate and compare multiple machine learning techniques for the characterization of carbonate minerals based on Raman-LIBS (Laser-Induced Breakdown Spectroscopy) spectroscopic data. To do so, a Ca-Mg prediction curve was created by mixing hydromagnesite and calcite at different concentration ratios. After their characterization by Raman and LIBS spectroscopy, different multivariable machine learning (Gaussian process regression, support vector machines, ensembles of trees, and artificial neural networks) were used to predict the concentration ratio of each sample from their respective datasets. The results obtained by separately analyzing Raman and LIBS data were then compared to those obtained by combining them. By comparing their performance, this work demonstrates that mineral discrimination based on Gaussian and ensemble methods optimized the combine of Raman-LIBS dataset outperformed those ensured by Raman and LIBS data alone. This demonstrated that the fusion of data combination and machine learning is a promising approach to optimize the analysis of spectroscopic data returned from Mars.Agencia Estatal de Investigación, grant (PID2022-142490OB-C32)Ministerio de Economía y Competitividad (MINECO),Grant/Award Number (RDE2018-102600-T

Near Real-Time Automated Early Mapping of the Perimeter of Large Forest Fires from the Aggregation of VIIRS and MODIS Active Fires in Mexico

In contrast with current operational products of burned area, which are generally available one month after the fire, active fires are readily available, with potential application for early evaluation of approximate fire perimeters to support fire management decision making in near real time. While previous coarse-scale studies have focused on relating the number of active fires to a burned area, some local-scale studies have proposed the spatial aggregation of active fires to directly obtain early estimate perimeters from active fires. Nevertheless, further analysis of this latter technique, including the definition of aggregation distance and large-scale testing, is still required. There is a need for studies that evaluate the potential of active fire aggregation for rapid initial fire perimeter delineation, particularly taking advantage of the improved spatial resolution of the Visible Infrared Imaging Radiometer (VIIRS) 375 m, over large areas and long periods of study. The current study tested the use of convex hull algorithms for deriving coarse-scale perimeters from Moderate Resolution Imaging Spectroradiometer (MODIS) and Visible Infrared Imaging Radiometer Suite (VIIRS) active fire detections, compared against the mapped perimeter of the MODIS collection 6 (MCD64A1) burned area. We analyzed the effect of aggregation distance (750, 1000, 1125 and 1500 m) on the relationships of active fire perimeters with MCD64A1, for both individual fire perimeter prediction and total burned area estimation, for the period 2012–2108 in Mexico. The aggregation of active fire detections from MODIS and VIIRS demonstrated a potential to offer coarse-scale early estimates of the perimeters of large fires, which can be available to support fire monitoring and management in near real time. Total burned area predicted from aggregated active fires followed the same temporal behavior as the standard MCD64A1 burned area, with potential to also account for the role of smaller fires detected by the thermal anomalies. The proposed methodology, based on easily available algorithms of point aggregation, is susceptible to be utilized both for near real-time and historical fire perimeter evaluation elsewhere. Future studies might test active fires aggregation between regions or biomes with contrasting fuel characteristics and human activity patterns against medium resolution (e.g., Landsat and Sentinel) fire perimeters. Furthermore, coarse-scale active fire perimeters might be utilized to locate areas where such higher-resolution imagery can be downloaded to improve the evaluation of fire extent and impactFunding for this study was provided by CONAFOR/CONACYT Projects “CO2-2014-3-252620” and “CO-2018-2-A3-S-131553” for the development and enhancement of a Forest Fire Danger Prediction System for Mexico, funded by the Sectorial Fund for forest research, development and technological innovation “Fondo Sectorial para la investigación, el desarrollo y la innovación tecnológica forestal”S

Diálogos sobre transdisciplina: los investigadores y su objeto de estudio

A la transdisciplinariedad se le ha definido como “una feliz transgresión de las fronteras entre las disciplinas” y es en este tono en que se presenta esta obra, que recopila las experiencias y reflexiones, las discusiones y propuestas de una veintena de investigadores y académicos que hablan sobre o desde la transdisciplina acerca de los temas de su interés o especialidad. La aproximación se da desde perspectivas académicas diversas y se adereza con expresiones estéticas que van desde la poesía hasta la pintura, a través de las cuales se busca ofrecer un espacio a las rutas posibles y limitaciones connaturales de acceder a la realidad para construir conocimiento “de frontera”, “en las fronteras”. Los abordajes son fruto de la exploración, filiación, encantos y desencantos por parte de los autores con la entidad de su búsqueda, quienes buscan contestar, entre otras, las siguientes cuestiones: ¿Cómo establecer un acercamiento transdisciplinar al objeto de estudio? ¿Qué hace a un objeto de estudio transdisciplinar? ¿Cómo impacta la transdisciplinariedad la identidad del académico? Una obra concebida desde una perspectiva más pedagógica que desde la doxa académica, con el interés de aportar una lectura amena para las reflexiones en torno a la trasgresión de las fronteras disciplinarias.ITESO, A.C

Lo tangible e intangible del diseño

1 archivo PDF (366 páginas)"El Departamento de Evaluación del Diseño, en el Tiempo de la División de Ciencias y Artes para el Diseño de la Universidad Autónoma Metropolitana, Azcapotzalco, publica este libro colectivo, donde se aborda la discusión y el análisis sobre "Lo tangible e intangible del diseño". Este libro tiene como finalidad el profundizar en distintas posiciones teóricas, metodológicas y empíricas, donde un grupo interdisciplinario de profesores investigadores del Departamento de Evaluación, desde la arquitectura, los estudios urbanos, la educación, la historia, la semiótica, el diseño de la comunicación gráfica y el industrial; buscan convergencias y discuten divergencias que puedan generar servir como referentes intelectuales y teóricos, en el diseño. Este libro es resultado del Cuarto Coloquio Departamental: Lo tangible e Intangible del Diseño. Evaluación de Objetos, Espacios, Mensajes, realizado durante el mes de septiembre del año 2004, el cual se constituyó como un espacio para el intercambio de experiencias académicas y profesionales, desde una perspectiva interdisciplinaria, centrada en la reflexión y la discusión sobre la manera de cómo se puede analizar, definir y evaluar, lo tangible y lo intangible en el diseño"

Co-limitation towards lower latitudes shapes global forest diversity gradients

The latitudinal diversity gradient (LDG) is one of the most recognized global patterns of species richness exhibited across a wide range of taxa. Numerous hypotheses have been proposed in the past two centuries to explain LDG, but rigorous tests of the drivers of LDGs have been limited by a lack of high-quality global species richness data. Here we produce a high-resolution (0.025° × 0.025°) map of local tree species richness using a global forest inventory database with individual tree information and local biophysical characteristics from ~1.3 million sample plots. We then quantify drivers of local tree species richness patterns across latitudes. Generally, annual mean temperature was a dominant predictor of tree species richness, which is most consistent with the metabolic theory of biodiversity (MTB). However, MTB underestimated LDG in the tropics, where high species richness was also moderated by topographic, soil and anthropogenic factors operating at local scales. Given that local landscape variables operate synergistically with bioclimatic factors in shaping the global LDG pattern, we suggest that MTB be extended to account for co-limitation by subordinate drivers

Worldwide trends in population-based survival for children, adolescents, and young adults diagnosed with leukaemia, by subtype, during 2000–14 (CONCORD-3) : analysis of individual data from 258 cancer registries in 61 countries

Background Leukaemias comprise a heterogenous group of haematological malignancies. In CONCORD-3, we analysed data for children (aged 0–14 years) and adults (aged 15–99 years) diagnosed with a haematological malignancy during 2000–14 in 61 countries. Here, we aimed to examine worldwide trends in survival from leukaemia, by age and morphology, in young patients (aged 0–24 years). Methods We analysed data from 258 population-based cancer registries in 61 countries participating in CONCORD-3 that submitted data on patients diagnosed with leukaemia. We grouped patients by age as children (0–14 years), adolescents (15–19 years), and young adults (20–24 years). We categorised leukaemia subtypes according to the International Classification of Childhood Cancer (ICCC-3), updated with International Classification of Diseases for Oncology, third edition (ICD-O-3) codes. We estimated 5-year net survival by age and morphology, with 95% CIs, using the non-parametric Pohar-Perme estimator. To control for background mortality, we used life tables by country or region, single year of age, single calendar year and sex, and, where possible, by race or ethnicity. All-age survival estimates were standardised to the marginal distribution of young people with leukaemia included in the analysis. Findings 164563 young people were included in this analysis: 121328 (73·7%) children, 22963 (14·0%) adolescents, and 20272 (12·3%) young adults. In 2010–14, the most common subtypes were lymphoid leukaemia (28205 [68·2%] patients) and acute myeloid leukaemia (7863 [19·0%] patients). Age-standardised 5-year net survival in children, adolescents, and young adults for all leukaemias combined during 2010–14 varied widely, ranging from 46% in Mexico to more than 85% in Canada, Cyprus, Belgium, Denmark, Finland, and Australia. Individuals with lymphoid leukaemia had better age-standardised survival (from 43% in Ecuador to ≥80% in parts of Europe, North America, Oceania, and Asia) than those with acute myeloid leukaemia (from 32% in Peru to ≥70% in most high-income countries in Europe, North America, and Oceania). Throughout 2000–14, survival from all leukaemias combined remained consistently higher for children than adolescents and young adults, and minimal improvement was seen for adolescents and young adults in most countries. Interpretation This study offers the first worldwide picture of population-based survival from leukaemia in children, adolescents, and young adults. Adolescents and young adults diagnosed with leukaemia continue to have lower survival than children. Trends in survival from leukaemia for adolescents and young adults are important indicators of the quality of cancer management in this age group.peer-reviewe

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Geochemical processes controlling the groundwater transport of contaminants released by a dump in an arid región of México

The Vado Carranza dump, located in the Mexicali Valley, Baja California, northwest Mexico, was operated for more than 15 years receiving about 30 tons/ day of solid wastes. The disposed wastes were periodically burned in open air. The presence of a shallow aquifer in the area makes the groundwater vulnerable to contamination processes. The purpose of this study was the evaluation of heavy metals content (Cu, Cd, Ni, Pb and Zn) in soil and groundwater in the vicinity of this dump. The results indicate high content of metals in soil, mainly at a superficial level, with the highest concentrations in the areas where burning of wastes occurred. Elevated concentrations of cadmium and copper were detected in groundwater with the highest concentrations occurring in monitoring wells located in the north side of the dump, downward of groundwater flow. Although the high content of metals in soil can be attributed to the burning of waste, other sources of pollution could be the agricultural irrigation in the vicinity of the dump. The program PHREEQC was used to model the geochemical evolution of groundwater. Results suggest that evaporation of the contaminated waters circulating below the landfill is one of the key processes that explain the increased concentration of contaminants in groundwater and its seasonal variations. As groundwater flows away from the dump, evaporation can concentrate the chemicals making the water more toxic. These results are important because they illustrate processes that are likely to occur in landfills located in other desert areas of the world

Fraccionamiento de metales pesados en un suelo contaminado del Valle de Mexicali

Heavy metals contamination is one of the greatest challenges related to the environment quality and human health. The introduction of these elements into natural systems may be due to various types of human activities such as agriculture and solid wastes disposal. In Mexicali Valley, agriculture represents the most important economic activity, however, the use of agrochemicals as well as the clandestine disposition of urban solid wastes have generated severe pollution problems affecting soil fertility and groundwater quality. The purpose of this research was to evaluate the heavy metals content in the different fractions of soil through the vadose zone (ZV) in a site located in Mexicali Valley, B.C. influenced by agriculture and solid wastes disposal. Soil samples were subjected to the sequential extraction procedure and then analyzed by atomic absorption spectrometry. The results obtained reveal a marked accumulation of metals from the surface until 50 cm depth. Seasonal variations in the water table, as well as agricultural irrigation, favors the solutes transport with heavy metals concentrations in groundwater higher than the standards for drinking water. The elements Cd, Cr y Ni are preferably distributed in the residual fraction of soil, limiting their mobility. Cu presented a strong association with organic matter, while Zn and Pb presented the greatest association with the exchangeable fraction.La contaminación provocada por metales pesados constituye uno de los grandes retos relacionados con la calidad del ambiente y la salud humana. La introducción de estos elementos en los sistemas naturales puede deberse a diversas actividades humanas entre ellas la agricultura y la disposición de residuos sólidos. En el Valle de Mexicali, la agricultura representa la actividad económica más importante, sin embargo, el uso de agroquímicos, así como la disposición clandestina de residuos sólidos urbanos (RSU) han generado problemas de contaminación severos afectando la fertilidad de suelos y la calidad de las aguas subterráneas. El propósito de esta investigación consistió en evaluar el contenido de metales pesados en diferentes fracciones de suelo a través de la zona vadosa (ZV) en un sitio ubicado en el Valle de Mexicali e influenciado por la agricultura y la disposición de residuos. Las muestras de suelo se sometieron al procedimiento de extracción secuencial y fueron analizadas mediante espectrometría de absorción atómica. Los resultados obtenidos revelan una marcada acumulación de metales desde la superficie hasta los primeros 50 cm de profundidad. Las variaciones estacionales del nivel freático, así como el riego agrícola favorecen el transporte de solutos observándose concentraciones de metales en el agua subterránea superiores a los estándares para agua potable. Los elementos Cd, Cr y Ni se distribuyen preferentemente en la fracción residual del suelo limitando así su movilidad. El Cu presentó una fuerte asociación con la materia orgánica en tanto que el Zn y Pb presentaron la mayor asociación con fracción intercambiable