379 research outputs found
Machine learning techniques to estimate the degree of binder activity of reclaimed asphalt pavement
Recycling; Machine learning; Artificial neural networksReciclaje; Aprendizaje automático; Redes neuronales artificialesReciclatge; Aprenentatge automàtic; Xarxes neuronals artificialsThis paper describes the development of novel/state-of-art computational framework to accurately predict the degree of binder activity of a reclaimed asphalt pavement sample as a percentage of the indirect tensile strength (ITS) using a reduced number of input variables that are relatively easy to obtain, namely compaction temperature, air voids and ITS. Different machine learning (ML) techniques were applied to obtain the most accurate data representation model. Specifically, three ML techniques were applied: 6th-degree multivariate polynomial regression with regularization, artificial neural network and random forest regression. The three techniques produced models with very similar precision, reporting a mean absolute error ranging from 12.2 to 12.8% of maximum ITS on the test data set. The work presented in this paper is an evolution in terms of data analysis of the results obtained within the interlaboratory tests conducted by Task Group 5 of the RILEM Technical Committee 264 on Reclaimed Asphalt Pavement. Hence, despite it has strong bonds with this framework, this work was developed independently and can be considered as a natural follow-up.Open access funding provided by Università degli Studi di Palermo within the CRUI-CARE Agreement. Part of this research was funded by the project RTI2018-096224-J-I00 that has been cofounded by the Spanish Ministry of Science and Innovation, inside the National Program for Fostering Excellence in Scientific and Technical Research, National Subprogram of Knowledge Generation, 2018 call, in the framework of the Spanish National Plan for Scientific and Technical Research and Innovation 2017–2020, and by the European Union, through the European Regional Development Fund, with the main objective of Promoting technological development, innovation and quality research. Part of this work was financially supported by the Italian Ministry of University and Research with the research Grant PRIN 2017 USR342 Urban Safety, Sustainability and Resilience
Use of lignocellulosic liquid waste from wood hardboard manufacture as bitumen emulsion extender for cold asphalt mixtures for low traffic roads
[Abstract:] During the wet process of manufacturing wood hardboards, a large amount of water contaminated with lignocellulosic waste is generated. With the aim of promoting the circular economy, it is interesting to find new uses for this liquid waste, rich in biopolymer lignin. The present research is a preliminary laboratory analysis of the feasibility of using this industrial waste as bitumen emulsion modifier or extender. To this purpose the lignocellulosic industrial waste was tested as partial substitute of bitumen emulsion for cold asphalt mixtures type grave emulsion. Particularly, GE-2 grave emulsions for low traffic roads have been manufactured. Substitution percentages of 0% (control), 5%, 10%, and 15% were analysed. The envelope water was visually determined. Also the optimum fluid content was obtained by means of the Modified Proctor Test. In addition, the optimum bitumen emulsion content, the compressive strength, and the water resistance of the cold asphalt mixtures were analysed conducting immersion-compression tests. All the tested percentages of lignocellulosic waste led to grave emulsions that could be used for low traffic roads, according to the Spanish specifications. Nevertheless, the results indicate decreased compressive strength with increasing liquid waste percentages. For this reason, only percentages of substitution up to 10% of liquid waste rich in lignin are considered adequate as bitumen emulsion extender
Determinación y evaluación de competencias asociadas a la actividad experimental
Las competencias son sistemas de reflexión-acción que han de poder transferirse de manera creativa a diferentes contextos, situaciones y problemas. Dan la posibilidad de desenvolverse en situaciones complejas en un contexto determinado, resultado de la integración, movilización y adecuación de capacidades, conocimientos, actitudes y valores. Esta complejidad ha de ser reconocida expresamente en el proceso de aprendizaje para que la propuesta pedagógica incluya las actividades que posibiliten el desarrollo de competencias. Ello conlleva la reflexión acerca del rol docente y de las estrategias didácticas necesarias para trabajar en un proceso de enseñanza de tales características.
Se describe en este trabajo lo realizado en el marco del proyecto Polimodal: desafíos alrededor de competencias experimentales, en el cual se llevó a cabo la elaboración de un modelo propio de competencias asociadas a la actividad experimental y se desarrolló un instrumento para el seguimiento del desarrollo de los componentes de las competencias que se ponen en juego durante el trabajo experimental.
En el marco del mencionado Proyecto, un grupo de docentes de Enseñanza Secundaria y de Universidad trabajaron conjuntamente en el análisis, discusión y búsqueda de consenso, entre actores de los dos niveles educativos, acerca de la idea de competencias y de cómo evaluar el aprendizaje de los estudiantes en este marco. Ello sirvió para revalorizar la importancia del trabajo experimental en el aprendizaje de las ciencias y en el desarrollo de competencias y podría constituirse en una estrategia válida para facilitar el tránsito de los alumnos entre ambos niveles
Evaluación de la Calidad Ambiental en el Area Metropolitana de Monterrey, N.L., México
La calidad y detrimento ambiental de los habitantes del Area Metropolitana de Monterrey (incluyesiete municipios) fue valorada. Esta estimación fue basada en la generación de un procesoaxiológico y conocimiento de la relación entre indicadores ambientales (sociodemográficos, salud,impacto ambiental, apertura social) y el proceso metodológico comprendido el método de valoresresiduales y un coeficiente de especialización funcional. Nuestros resultados indican queúnicamente el municipio de San Pedro Garza García tiene un índice de calidad ambientalaltamente significativo (0.7433). Mientras las municipalidades de General Escobedo (0.7599) yApodaca (0.7403), fueron las únicas dos áreas con índices de detrimento ambiental altamentesignificativos.AbstractThe quality and deterioration of the enviroment of inhabitants of the Urban Area of Monterrey (include seven municipalities) was assed. This estimation was based on the generation of anaxiological process and knowledge of the realtionship between enviromental indicators(sociodemographic, health, enviormental impact and social features) and the methodologicalprocess comprising residual values and the coeficients of especialization. Our results indicated thatonly the municipality of San Pedro Garza García had high significant index of enviromental quality(0.7433), while the municipalities of General Escobedo (0.7599) and Apodaca (0.7403) where theonly two areas with high significant deterioration indices.Palabras clave: calidad ambiental; indicadores ambientales; métodos, Monterrey; México,enviroment quality, enviroment indicators, methods
Taxonomic variations in the gut microbiome of gout patients with and without tophi might have a functional impact on urate metabolism
[Objective] To evaluate the taxonomic composition of the gut microbiome in gout patients with and without tophi formation, and predict bacterial functions that might have an impact on urate metabolism.[Methods] Hypervariable V3–V4 regions of the bacterial 16S rRNA gene from fecal samples of gout patients with and without tophi (n = 33 and n = 25, respectively) were sequenced and compared to fecal samples from 53 healthy controls. We explored predictive functional profiles using bioinformatics in order to identify differences in taxonomy and metabolic pathways.
[Results] We identified a microbiome characterized by the lowest richness and a higher abundance of Phascolarctobacterium, Bacteroides, Akkermansia, and Ruminococcus_gnavus_group genera in patients with gout without tophi when compared to controls. The Proteobacteria phylum and the Escherichia-Shigella genus were more abundant in patients with tophaceous gout than in controls. Fold change analysis detected nine genera enriched in healthy controls compared to gout groups (Bifidobacterium, Butyricicoccus, Oscillobacter, Ruminococcaceae_UCG_010, Lachnospiraceae_ND2007_group, Haemophilus, Ruminococcus_1, Clostridium_sensu_stricto_1, and Ruminococcaceae_UGC_013). We found that the core microbiota of both gout groups shared Bacteroides caccae, Bacteroides stercoris ATCC 43183, and Bacteroides coprocola DSM 17136. These bacteria might perform functions linked to one-carbon metabolism, nucleotide binding, amino acid biosynthesis, and purine biosynthesis. Finally, we observed differences in key bacterial enzymes involved in urate synthesis, degradation, and elimination.
[Conclusion] Our findings revealed that taxonomic variations in the gut microbiome of gout patients with and without tophi might have a functional impact on urate metabolism.This study was supported by the Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra” and the Grant INF-2016-01-269675 from the Consejo Nacional de Ciencia y Tecnología (CONACYT)
Protocolo de implementación del LMyS : implementación del laboratorio de modelamiento y simulación
La creación del Laboratorio de Modelamiento y Simulación (LMyS) se lleva
a cabo con el objeto de adelantar investigación original y apoyar los proyectos
en desarrollo dentro de la Facultad de Administración, mediante el modelamiento
desde las ciencias de la complejidad y la matemática no clásica. Este
desarrollo obedece a la necesidad de dar respuestas a la realidad cambiante y
dinámica en la que los modelos tradicionales no han dado una respuesta
satisfactoria o suficiente. Gracias al LMyS se materializan los avances y desarrollos
de los grupos de investigación de la Facultad a través del modelamiento
y simulación con lógicas no-clásicas (modal, difusa, paraconsistente
y lógica cuántica, entre otras), que permitan posteriormente producir a nivel
computacional implementaciones de estos modelos. De este modo, mediante
las contribuciones del LMyS se busca que, por un lado, exista innovación en
el conocimiento con el rigor apropiado y a niveles mundiales en el estudio de
los sistemas dinámicos modelados a partir de las organizaciones, y, por otro,
se erija como una herramienta para el sector empresarial y productivo en los
procesos de toma de decisión.
Al mismo tiempo que adelanta investigaciones que conducen a, y se
condensan en, registros y patentes, el LMyS quiere contribuir al apoyo a la
investigación en la disciplina de la administración. Así, el LMyS hace parte
del gran proyecto de la Facultad de Administración de la Universidad del
Rosario que le permitirá abordar problemáticas actuales y futuras, en torno
a la dinámica económica y social, pero con enfoques igualmente políticos,
financieros y otros en el marco de un mundo caracterizado por una enorme
complejidad (creciente).
El desarrollo de la investigación de la Facultad de Administración tiene
como una gran influencia las ciencias de la complejidad, tratando de entregar
a la comunidad empresarial herramientas, modelos o perspectivas diferentes
que le permitan enfrentar la incertidumbre y disminuir los niveles de riesgo
Simulando el análisis de hacinamiento sectorial en empresas colombianas
El objetivo de este trabajo es hacer una interpretación de la herramienta “hacinamiento
estratégico” la cual fue propuesta por el profesor Luis F. Restrepo P.
y Hugo A. Rivera en el año 2006 a través del Centro de Estudios Empresariales
para la Perdurabilidad. El análisis de hacinamiento es una herramienta que
hace parte complementaria del Análisis Estructural de Sectores Estratégicos
(AESE), la cual muestra la percepción de imitación que tiene una empresa
sobre un sector estratégico determinado.
En este trabajo se presenta una interpretación formal de los planteamientos
teóricos en los cuales se basa el hacinamiento; luego de la formalización se
desarrolla una simulación que muestra nuevas formas de observar la imitación
en un sector estratégico. Las técnicas utilizadas para la nueva observación son
el análisis de discriminante, y la probabilidad condicional
The Mice at play in the CALIFA survey: A case study of a gas-rich major merger between first passage and coalescence
We present optical integral field spectroscopy (IFS) observations of the
Mice, a major merger between two massive (>10^11Msol) gas-rich spirals NGC4676A
and B, observed between first passage and final coalescence. The spectra
provide stellar and gas kinematics, ionised gas properties and stellar
population diagnostics, over the full optical extent of both galaxies. The Mice
provide a perfect case study highlighting the importance of IFS data for
improving our understanding of local galaxies. The impact of first passage on
the kinematics of the stars and gas has been significant, with strong bars
likely induced in both galaxies. The barred spiral NGC4676B exhibits a strong
twist in both its stellar and ionised gas disk. On the other hand, the impact
of the merger on the stellar populations has been minimal thus far: star
formation induced by the recent close passage has not contributed significantly
to the global star formation rate or stellar mass of the galaxies. Both
galaxies show bicones of high ionisation gas extending along their minor axes.
In NGC4676A the high gas velocity dispersion and Seyfert-like line ratios at
large scaleheight indicate a powerful outflow. Fast shocks extend to ~6.6kpc
above the disk plane. The measured ram pressure and mass outflow rate
(~8-20Msol/yr) are similar to superwinds from local ULIRGs, although NGC4676A
has only a moderate infrared luminosity of 3x10^10Lsol. Energy beyond that
provided by the mechanical energy of the starburst appears to be required to
drive the outflow. We compare the observations to mock kinematic and stellar
population maps from a merger simulation. The models show little enhancement in
star formation during and following first passage, in agreement with the
observations. We highlight areas where IFS data could help further constrain
the models.Comment: 23 pages, 13 figures, accepted to A&A. A version with a complete set
of high resolution figures is available here:
http://www-star.st-and.ac.uk/~vw8/resources/mice_v8_astroph.pd
Telomere Length as a Biomarker for Adiposity Changes after a Multidisciplinary Intervention in Overweight/Obese Adolescents: The EVASYON Study
[Context]
Telomeres are biomarkers of biological aging. Shorter telomeres have been associated with increased adiposity in adults. However, this relationship remains unclear in children and adolescents.
[Objective]
To evaluate the association between telomere length (TL) and adiposity markers in overweight/obese adolescents after an intensive program. We hypothesize that greater TL at baseline would predict a better response to a weight loss treatment.
Design, Setting, Patients and Intervention
The EVASYON is a multidisciplinary treatment program for adolescents with overweight and obesity that is aimed at applying the intervention to all possibly involved areas of the individual, such as dietary habits, physical activity and cognitive and psychological profiles. Seventy-four participants (36 males, 38 females, 12–16 yr) were enrolled in the intervention program: 2 months of an energy-restricted diet and a follow-up period (6 months).
[Main Outcome]
TL was measured by quantitative real-time polymerase chain reaction at baseline and after 2 months; meanwhile, anthropometric variables were also assessed after 6 months of follow-up.
[Results]
TL lengthened in participants during the intensive period (+1.9±1.0, p<0.001) being greater in overweight/obese adolescents with the shortest telomeres at baseline (r = −0.962, p<0.001). Multivariable linear regression analysis showed that higher baseline TL significantly predicted a higher decrease in body weight (B = −1.53, p = 0.005; B = −2.25, p = 0.047) and in standard deviation score for body mass index (BMI-SDS) (B = −0.22, p = 0.010; B = −0.47, p = 0.005) after the intensive and extensive period treatment respectively, in boys.
[Conclusion]
Our study shows that a weight loss intervention is accompanied by a significant increase in TL in overweight/obese adolescents. Moreover, we suggest that initial longer TL could be a potential predictor for a better weight loss response.Research relating to this work was funded by grants from the Health Research Fund from the Carlos III Health Institute from Ministry of Health and Consumption, Fondo de Investigación Sanitaria (FIS; PI051579, PI051080) for the EVASYON project; Línea Especial, Nutrición y Obesidad (University of Navarra); Spanish Ministry of Science and Innovation (MICINN) [SAF2010-20367]; Carlos III Health Institute [Centro de Investigación Biomédica en Red (CIBER) project, CB06/03/1017], and RETICS network. The scholarship to S. García-Calzón from the FPU ‘Formación de Profesorado Universitario’ from the Spanish Ministry is fully acknowledged
Predicting bee community responses to land-use changes: Effects of geographic and taxonomic biases
Land-use change and intensification threaten bee populations worldwide, imperilling pollination services. Global models are needed to better characterise, project, and mitigate bees' responses to these human impacts. The available data are, however, geographically and taxonomically unrepresentative; most data are from North America and Western Europe, overrepresenting bumblebees and raising concerns that model results may not be generalizable to other regions and taxa. To assess whether the geographic and taxonomic biases of data could undermine effectiveness of models for conservation policy, we have collated from the published literature a global dataset of bee diversity at sites facing land-use change and intensification, and assess whether bee responses to these pressures vary across 11 regions (Western, Northern, Eastern and Southern Europe; North, Central and South America; Australia and New Zealand; South East Asia; Middle and Southern Africa) and between bumblebees and other bees. Our analyses highlight strong regionally-based responses of total abundance, species richness and Simpson's diversity to land use, caused by variation in the sensitivity of species and potentially in the nature of threats. These results suggest that global extrapolation of models based on geographically and taxonomically restricted data may underestimate the true uncertainty, increasing the risk of ecological surprises
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