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Kinetic and hydrogen production analysis in the sequential valorization of a Populus clone by cold alkaline extraction and pyrolysis
Get PDFThis work employed a two-step biorefining process, consisting of a hemicellulose-rich liquor production through ultrasound-assisted cold alkaline extraction (CAE), followed by thermochemical treatment of the resultant solid phase. The post-CAE solid phase's pyrolytic potential was assessed by application of thermogravimetric analysis (TGA) and Friedman's isoconversional method, and also from hydrogen production. The solid phases remaining after the CAE treatment were more reactive than the untreated raw material. Notably, the alkali concentration employed in the first step was the individual variable most pronounced influence on their activation energy (Ea). Thus, at a degree of conversion α = 0.50, Ea ranged from 109.7 to 254.3 kJ/mol for the solid phases, compared to 177 kJ/mol for the raw material; this value decreased with rising glucan content. At maximal degradation, the post-CAE solid phases produced up to 15.57% v/v more hydrogen than did the untreated raw material.Project PID2020-112875RB-C21, MCIN/AEI /10.13039/501100011033/Spain's Ministry of Science and Innovation and the National Research Program Oriented to the Challenges of Society PRE2021-097925 support (funded by MCIN/AEI/10.13039/501100011033 and by the FSE+)/Ministry of Science and Innovation and the State Research AgencyIngeniería Química, Química Física y Ciencias de los Materiale
Exploring prospective teachers' stances in making sense of students' mathematical ideas
Get PDFIn this paper, we explore the critical practice of making sense of students’ mathematical
ideas. We extend previous research by studying stances prospective teachers adopt, the
extent or depth to which they do so, and the types of prospective teachers making sense
of students’ mathematical ideas. Analyzing the responses of 123 prospective teachers to
students’ different ideas on an ambiguous mathematical task, our study identifies various
stances—descriptive, evaluative, comparative, interpretive, inquiry-based, connective, and
projective—and explores the complexity of attributing value, meaning, and significance to
student ideas. Our findings offer insights into various types of making sense of students’
ideas and suggest that different kinds of attributions are at play for the purposes of
observation, assessment, understanding and projection/prediction.Open Access funding enabled and organized by CAUL and its Member Institutions. This work
was funded by Project PID2021-122180OB-I00, financed by the Government of Spain, and Project
ProyExcel_00297, supported by the Andalusian Government. We are also grateful for the support from the
COIDESO research centre at the University of Huelva and DESYM (HUM-168). Additionally, this research
benefited from the contributions of the MTSK network, sponsored by AUIP.Didácticas Integrada
Retraimiento de la subcontratación: Estimación temprana usando datos administrativos
Get PDFLabor flexibility policies have increased temporary and subcontracted
jobs. These types of employment are associated with lower quality jobs. In this
paper, five-year economic census data and social security administrative data
were collected to estimate, in non-census years, out-of-sample the percentage
of subcontracted jobs. This evidence is relevant for assessing the impact of a
legislation that banned subcontracting. Predictor variables such as time fixed
effects, industry, and the rate of temporary workers were used. The results
show a significant decrease in subcontracting, particularly in the secondary
sector. These findings raise the need for future research on improvements in
post-reform well-being in the labor market.Las políticas de flexibilización laboral han aumentado los empleos temporales y subcontratados. Esas categorías de empleo están asociadas con empleos de menor calidad. En este artículo, se recopilaron datos quinquenales del censo económico y datos administrativos de la seguridad social para estimar fuera de la muestra, en años no censales, el porcentaje de trabajos subcontratados. Esta evidencia es relevante para evaluar el impacto de una legislación que prohibió la subcontratación. En la estimación se utilizaron efectos temporales y variables predictoras como la industria, el tamaño de la empresa y la tasa de trabajadores temporales. Los resultados muestran un descenso importante de la subcontratación, particularmente en el sector secundario. Estos hallazgos plantean la necesidad de investigación futura sobre mejoras en el bienestar que haya habido en el mercado laboral
The viability of implementing a yoga program in elder people: a pilot study
Get PDFEl envejecimiento poblacional se ha incrementado
a nivel mundial, siendo un hecho biológico, social y
cultural. En Aragón, se impulsan programas de envejecimiento activo que apoyan un envejecimiento en positivo y responsable. El yoga se encuentra reconocido
dentro de estas actividades impartidas en los Hogares
de Mayores. En este trabajo se busca explorar la viabilidad y eficacia preliminar de implementar un programa
de yoga en personas mayores.
La muestra fue de 33 personas mayores de 60 años,
de tres Hogares de Mayores del Instituto Aragonés de
Servicios Sociales (IASS). El programa de yoga tuvo una
duración de 16 semanas, dos horas a la semana.
Los resultados de este estudio ponen de manifiesto
un efecto positivo de la práctica del Yoga en la percepción de la salud y la satisfacción con la vida en personas
mayores de 60 años. La implantación de este tipo de
programas se estima como viable y bien aceptada por
los potenciales usuarios/asThe population aging has increased in general way,
being a biological, social and cultural fact. In Aragon,
they promote active aging programs that support a
positive and responsible aging. The yoga is recognized
within these activities taught in nursing homes.
This work aims to explore the preliminary viability
and efficacy of implementing a yoga program in elder
people.
The sample was composed of 33 members, older
than 60 years, of three nursing homes of the Aragonese Institute of Social Services (AISS). The yoga program
had a duration of 16 weeks, two hours a week.
The results of this study showed that the practice of
Yoga promoted a positive effect on the perception of
health and satisfaction with life in people over 60 years
of age. The implementation of this type of program is
considered viable and well accepted by potential user
Factors Influencing Occupational Stress Perceived by Emergency Nurses During Prehospital Care: A Systematic Review
Get PDFObjective: To assess personal and work-related factors influencing the stress levels of nurses during prehospital care. Specifically, to identify associations between the level of perceived stress, the degree of professional experience, and the level of knowledge. Secondly, to examine the relationship between stress levels and violence in the work environment. And third, to investigate the main protective factors against work-related stress during prehospital care.
Methods: Systematic review in PubMed, WOS, Enfispo, Cochrane, and LILACS databases following the PRISMA methodology (last search 08/Aug/2023). Following the PECO framework, studies on occupational stress factors in ambulance emergency nurses were investigated. Studies in English or Spanish, from 2013 to 2023, and only research articles were admitted, thus excluding reviews, dissertations, and grey literature. Possible bias and level evidence were assessed using critical appraisal tools and GRADE. This protocol was registered in PROSPERO with code CRD42023446080.
Results: Fourteen articles were selected, and n=855 prehospital nurses were identified. One study was a clinical trial, and the others were observational and qualitative. The level of evidence was very low (n=7), low (n=6), and moderate (n=1); any study was excluded due to methodological bias. Five categories of stressors were extracted: the management of the health service (ie, workload organisation, and resources), patient care (mainly paediatric care), interpersonal stressors (relationship with peers), environmental factors (exposure to injuries), and personal factors (training, experience, and coping strategies). Violence at work is frequent for prehospital nurses, implying both verbal and physical aggressions. Support from peers was associated with positive results against stress.
Conclusion: Managing workload and improving resources in the work environment are essential to reduce fatigue and allow emotional processes to be addressed. Providing workers with coping skills also imposes on them the responsibility to cope with stress. Collective awareness is the main element in reducing the incidence of stress.Departamento de Biología Ambiental y Salud Públic
The mediational role of positive youth development in the relationship between physical activity and health-related quality of life in adolescents from urban and rural environments
Get PDFThe aim of this study was to analyse the role of the 5Cs of Positive
Youth Development (PYD) in the relationship between physical activity
(PA) and health-related quality of life (HRQoL), in a sample of adolescents
enrolled at public secondary schools in both rural and urban
environments in Huelva (Spain). The sample comprised 418 adolescents
(Mean age = 14.40; SD = 1.20; 53% boys). A cross-sectional design
was employed. PA (PAQ-A), Adherence to the Mediterranean Diet
(KIDMED), PYD and HRQoL (KIDSCREEN-27) were assessed using selfreport
questionnaires. The results indicated that adolescents from rural
environments were more physically active and achieved higher scores
in PYD and HRQoL dimensions compared to those from urban environments.
Mediation analyses demonstrated that the competence dimension
of PYD positively mediated the relationship between PA and
HRQoL. Consequently, this study highlights the importance of implementing
PA interventions considering PYD and its positive impact on
HRQoL.This work and the APC was supported by the Excellence Research Projects Fund of the Consejería de Universidad,
Investigación e Innovación of the Junta de Andalucía, grant number [PROYEXCEL_00303], awarded to D.G-B.Psicología Social, Evolutiva y de la Educació
Gut-gonad crosstalk in mice exposed to a “chemical cocktail” combining metabolomics and microbial profile by amplicon sequencing
Get PDFTestes are very prone to be damaged by environmental pollutants, but there is a lack of information about the impact of “chemical cocktails” (CC) on the testicular metabolome and the possible influence in the gut-gonad crosstalk. For this, BALB/c mice were given flumequine and diclofenac orally in food and potentially toxic trace elements (Cd, Hg, As) in drinking water. A mice group was supplemented with selenium, a well-known antagonist against many pollutants. Our results revealed that the steroid 5-alpha-androstan-17-beta-ol propionate, suggested as a parameter of androgenicity independent of testosterone levels, proline that improves reproductive indicators in male rabbits affected by environmental stress) among others metabolites are only present after CC exposure with rodent and selenium supplemented diet. Selenium also antagonized the up-or down-regulation of anandamide (20:l, n-9) (p 0,05 and FC 0.74 of CC-Se vs C), that regulates gonadotropin-releasing hormones in mammals, 2,3-dinor-11b-PGF2a (p 0,05 and FC 0.34 of CC-Se vs C), which has been related with reproductive hormones, besides others testicular metabolites altered by the exposure to the CC and reversed the levels to control. Moreover, numerous significant associations between gut microbes and testicular metabolites indicated a possible impact of pollutants in the testes mediated by gut microbiota due to a gut-gonad crosstalk.This work was supported by the projects: PID2021-123073NB-C21 from the Spanish Ministry of Science and Innovation (MICIN). Generaci´ on del Conocimiento. MCI/AEI/FEDER “Una manera de hacer Europa”; UHU-1256905 and UHU-202009 from the FEDER Andalusian Operative Program 2014–2020 (Ministry of Economy, Knowledge, Business and Universities, Regional Government of Andalusia, Spain). The authors are grateful to FEDER (European Community) for financial support, Grant UNHU13-1E-1611. CPM thanks MICIN for a predoctoral grant (ref. PRE2019-091,650). MSR and MCC also acknowledge the award of the Spanish Government MCIN/AEI to the Institute of Agrochemistry and Food Technology (IATA-CSIC) as Centre of Excellence Severo Ochoa (CEX2021-001189-S MCIN/AEI / 10.13039/ 501100011033). The authors would like to acknowledge the support from The Ram´ on Areces Foundation (ref. CIVP19A5918). Funding for open access charge: Universidad de Huelva/CBUA.Química "Profesor José Carlos Vílchez Martín
Exploring Cellulose Triacetate Nanofibers as Sustainable Structuring Agent for Castor Oil: Formulation Design and Rheological Insights
Get PDFDeveloping gelled environmentally friendly dispersions in oil media is a hot topic for
many applications. This study aimed to investigate the production of electrospun cellulose triacetate
(CTA) nanofibers and to explore their potential application as a thickening agent for castor oil.
The key factors in the electrospinning process, including the intrinsic properties of CTA solutions
in methylene chloride (DCM)/ethanol (EtOH), such us the shear viscosity, surface tension, and
electrical conductivity, were systematically studied. The impact of the CTA fiber concentration and
the ratio of DCM/EtOH on the rheological properties of the gel-like dispersions in castor oil was
then investigated. It was found that dispersions with a non-Newtonian response and above a critical
concentration (5 wt.%), corresponding to approximately 2–2.5 times the entanglement concentration,
are required to produce defect-free nanofibers. The average fiber diameter increased with CTA
concentration. Further, the morphology and texture of the electrospun nanofibers are influenced by
the ratio of solvents used. The rheological properties of dispersions are strongly influenced by the
concentration and surface properties of nanofibers, such as their smooth or porous textures, which
allow their modulation. Compared to other commonly used thickeners, such as synthetic polymers
and metal soaps, CTA electrospun nanofibers have a much higher oil structuring capacity. This work
illustrated the potential of using CTA nanofibers as the foundation for fabricating gel-like dispersions
in oil media, and thus exerting hierarchical control of rheological properties through the use of a
nanoscale fabrication technique.This research was supported by the FEDER European Programme and Junta de Andalucía (grant number: PY20_00751), and by EPIT2020, Estrategia de Política de Investigación y Transferencia (Comisión Europea; Universidad de Huelva; Junta Andalucía), Project UHU202029.Ingeniería Química, Química Física y Ciencias de los Materiale
Young People and Social Networks: News Consumption Habits and Credibility of the News
Get PDFLas redes sociales se han erigido en un soporte de suma eficacia para la difusión de la información de actualidad entre sectores cada vez más amplios de la población, y particularmente, entre los jóvenes, que tienen en estos canales una vía preferente de socialización y conocimiento del entorno. El objetivo fundamental de este trabajo reside en analizar el consumo informativo en redes sociales por parte de la población española de entre 15 y 24 años, con la intención de conocer cómo accede a las noticias, qué interacciones lleva a cabo y qué factores le generan confianza, a partir de un cuestionario “online” suministrado a una muestra de carácter nacional, representativa de la población objeto de estudio (n=1.067) y cinco grupos de discusión (n=97). Los resultados ref lejan una alta exposición diaria a las redes, constituidas en el medio más habitual de consumo informativo para los jóvenes, quienes muestran escasa propensión a contrastar las noticias. La mayoría de las informaciones las reciben de manera involuntaria, limitándose por lo general a leerlas o, a lo sumo, compartirlas con sus contactos; y suelen suscitarles poca confianza. No obstante, el análisis de los factores sociodemográficos arroja que variables como la edad, el nivel formativo y el posicionamiento ideológico inf luyen en la credibilidad que los jóvenes otorgan a los contenidos de actualidad que difunden las redes y a las fuentes de las que estos procedenSocial networks have become extremely effective platforms for the dissemination of up-to-the-minute news among ever wider sectors of the population, particularly among young people, for whom these channels are a preferred means of socialization and of understanding their environment. The main objective of this study is to analyze the news consumption of the Spanish population aged between 15 and 24 years on social networks, with the intention of understanding how they access news, what interactions take place, and what factors engender trust, as per an online questionnaire administered to a national sample representative of the population under study (n=1,067) and five focus groups (n=97). The findings reflect a high daily exposure to the networks, which are the most common means of news consumption for young people, who show little inclination to fact-check. They receive most news items incidentally; usually, they simply read them or, at most, share them with their contacts, and they tend to attribute very little trustworthiness to them. However, the analysis of sociodemographic factors shows that variables such as age, educational level, and ideological positioning influence the credibility that young people give to the current affairs content that the networks disseminate and to the sources from which they com