316 research outputs found
La genética en el cine y los obstáculos para su aprendizaje formal
El objetivo de este trabajo es comprobar si los significados sobre genética transmitidos por las películas que los estudiantes ven podrían generar concepciones alternativas sobre el tema. Así, se comparan dos fuentes de significados: los transmitidos por las películas y los personales de los estudiantes. El estudio muestra que los significados transmitidos por las películas pueden reforzar las ideas previas de los estudiantes, convirtiéndose así en obstáculos de aprendizaje
The Role of Negative and Positive Urgency in the Relationship Between Craving and Symptoms of Problematic Video Game Use
Spanish Research Agency (Agencia Española de Investigación),Spanish Ministry of Science
and Innovation (Ministerio de Ciencia e Innovación; MCIN/AEI/10.13039/501100011033/)PID2020-
116535 GB-I00.Grant (FPU21/00462, Ministerio
de Ciencia e Innovación)Grant (PRE2018-085150,
Ministerio de Ciencia, Innovación y Universidades
Socio-cultural factors for breastfeeding cessation and their relationship with child diarrhoea in the rural high-altitude Peruvian Andes - a qualitative study
BACKGROUND: In some areas of the world, breast milk is seen as a potential source of child diarrhoea. While this belief has been explored in African and Southeast Asian countries, it remains vastly understudied in Latin American contexts. We investigate socio-cultural factors contributing to breastfeeding cessation in rural high-altitude populations of the Peruvian Andes. The role of socio- cultural factors in the local explanatory model of child diarrhoea, and whether these perceptions were integrated in the local healthcare system were assessed. METHODS: Within the framework of a randomised controlled trial, we conducted semi-structured interviews with 40 mothers and 15 health personnel from local healthcare centres involved in the trial. RESULTS: Cultural beliefs on breastfeeding cessation included the perception that breast milk turned into "blood" after six months and that breastfeeding caused child diarrhoea. We identified eight local types of child diarrhoea, and women linked six of them with breastfeeding practices. "Infection" was the only diarrhoea mothers linked to hygiene and the germ disease concept and perceived as treatable through drug therapy. Women believed that other types of diarrhoea could not be treated within the formal healthcare sector. Interviews with health personnel revealed no protocol for, or consensus about, the integration of the local explanatory model of child diarrhoea in local healthcare and service provision. CONCLUSIONS: The local explanatory model in rural Andean Peru connected breastfeeding with child diarrhoeas. Cultural beliefs regarding diarrhoea management may increase home treatments, even in cases of severe diarrhoeal episodes. Future national breastfeeding support programmes should promote peer-counselling approaches to reduce negative attitudes towards breastfeeding and health practitioners. Local explanatory models should be incorporated into provincial and regional strategies for child diarrhoea management to promote equity in health and improve provider-patient relationships
What Role Do Traditional Beliefs Play in Treatment Seeking and Delay for Buruli Ulcer Disease?–Insights from a Mixed Methods Study in Cameroon
Victims of Buruli ulcer disease (BUD) frequently report to specialized units at a late stage of the disease. This delay has been associated with local beliefs and a preference for traditional healing linked to a reportedly mystical origin of the disease. We assessed the role beliefs play in determining BUD sufferers' choice between traditional and biomedical treatments.Anthropological fieldwork was conducted in community and clinical settings in the region of Ayos and Akonolinga in Central Cameroon. The research design consisted of a mixed methods study, triangulating a qualitative strand based on ethnographic research and quantitative data obtained through a survey presented to all patients at the Ayos and Akonolinga hospitals (N = 79) at the time of study and in four endemic communities (N = 73) belonging to the hospitals' catchment area.The analysis of BUD sufferers' health-seeking behaviour showed extremely complex therapeutic itineraries, including various attempts and failures both in the biomedical and traditional fields. Contrary to expectations, nearly half of all hospital patients attributed their illness to mystical causes, while traditional healers admitted patients they perceived to be infected by natural causes. Moreover, both patients in hospitals and in communities often combined elements of both types of treatments. Ultimately, perceptions regarding the effectiveness of the treatment, the option for local treatment as a cost prevention strategy and the characteristics of the doctor-patient relationship were more determinant for treatment choice than beliefs.The ascription of delay and treatment choice to beliefs constitutes an over-simplification of BUD health-seeking behaviour and places the responsibility directly on the shoulders of BUD sufferers while potentially neglecting other structural elements. While more efficacious treatment in the biomedical sector is likely to reduce perceived mystical involvement in the disease, additional decentralization could constitute a key element to reduce delay and increase adherence to biomedical treatment
Stir Casting Routes for Processing Metal Matrix Syntactic Foams: A Scoping Review
Metal matrix syntactic foams (MMSFs) are advanced lightweight materials constituted by a metallic matrix and a dispersion of hollow/porous fillers. Physical and mechanical properties can be fitted regarding matrix and filler properties and processing parameters. Their properties make them potential materials for sectors where density is a limiting parameter, such as transport, marine, defense, aerospace, and engineering applications. MMSFs are mainly manufactured by powder metallurgy, infiltration, and stir casting techniques. This study focuses on the current stir casting approaches and on the advances and deficiencies, providing processing parameters and comparative analyses on porosity and mechanical properties. PRISMA approaches were followed to favor traceability and reproducibility of the study. Stir casting techniques are low-cost, industrially scalable approaches, but they exhibit critical limitations: buoyancy of fillers, corrosion of processing equipment, premature solidification of molten metal during mixing, cracking of fillers, heterogeneous distribution, and limited incorporation of fillers. Six different approaches were identified; four focus on limiting buoyancy, cracking, heterogeneous distribution of fillers, and excessive oxidation of sensitive matrix alloys to oxygen. These improvements favor reaching the maximum porosity of 54%, increasing the fillers size from a few microns to 45 mm, reducing residual porosity by ±4%, synthesizing bimodal MMSFs, and reaching maximum incorporation of 74 vol%.</jats:p
Acceptance and uptake of improved biomass cookstoves in Peru: learning from system level approaches to transform large-scale cooking interventions
Improved biomass cookstoves (ICS) are cooking technologies that increase wellbeing and reduce household air pollution. With the goal of identifying factors influencing ICS acceptance and uptake at five system levels (intrapersonal, interpersonal, community, institutional, and policy), we carried out a qualitative study in three regions in Peru. We conducted 32 focus group discussions (243 ICS users) and 26 semi-structured interviews with key stakeholders, applying a combination of two system-level frameworks for analysis: the socio-ecological model and the ICS adoption domain. Enabling and impeding factors at each level were closely related to each other. Decisions made by policy makers - often centralised and not considering local/regional realities - strongly influenced acceptance and barriers at lower levels. ICS acceptance and uptake tended to be low when ICS users were not involved from the start. Most ICS programmes focused on stove distribution outputs, without considering community needs, such as training on ICS building, maintenance and repair, or issues related to spare part availability, which is a strong barrier to sustained uptake of ICS. Using a combination of models that allows one to examine facilitators and barriers at multiple levels, as well as the interactions of those levels, was useful in assessing potential improvements to intervention design, facilitating programme success, preventing unforeseen programme adaptations, and improving cost-effectiveness of interventions
Assemblies of magnetite nanoparticles extracted from magnetotactic bacteria: A magnetic study
Self-assembly has emerged as a suitable technique for tuning the properties of nanoparticles. In this work, we report the self-assembly of magnetosomes assisted by an external magnetic field. The magnetosomes are magnetite nanoparticles biomineralized by magnetotactic bacteria Magnetospirillum gryphiswaldense. These nanoparticles present truncated cubo-octahedral morphology with a mean diameter of ˜36 nm and are surrounded by a lipid bilayer membrane with a thickness ˜2-4 nm. The use of the appropriate preparation conditions, such as initial colloidal concentration and magnetic fields applied during deposition allowed us to obtain very reproducible self-assembled 2D patterns. Homogeneous ensembles of magnetosomes onto silicon and carbon surfaces are composed of elongated structures in the form of wide chains that cover a large area of the substrates. Transmission electron microscopy image and off-axis electron holography showed the map of the stray magnetic fields produced by these assemblies. The induced magnetic anisotropy was analyzed by measuring the hysteresis loops of the assemblies at different angles in a magneto-optical Kerr effect magnetometer. The evolution of the coercive field and remanence verified the presence of well-defined patterns. The experimental results were analyzed on the based of a biaxial model
Sustainability indicator for the prevention of potential thermal interferences between groundwater heat pump systems in urban aquifers
The steady increase of geothermal systems using groundwater is compromising the renewability of the geothermal resources in shallow urban aquifers. To ensure sustainability, scientifically-based criteria are required to prevent potential thermal interferences between geothermal systems. In this work, a management indicator (balanced sustainability index, BSI) applicable to groundwater heat pump systems is defined to assign a quantitative value of sustainability to each system, based on their intrinsic potential to produce thermal interference. The BSI indicator relies on the net heat balance transferred to the terrain throughout the year and the maximum seasonal thermal load associated. To define this indicator, 75 heating-cooling scenarios based in 23 real systems were established to cover all possible different operational conditions. The scenarios were simulated in a standard numerical model, adopted as a reference framework, and thermal impacts were evaluated. Two polynomial regression models were used for the interpolation of thermal impacts, thus allowing the direct calculation of the sustainability indicator developed as a function of heating-cooling ratios and maximum seasonal thermal loads. The BSI indicator could provide authorities and technicians with scientifically-based criteria to establish geothermal monitoring programs, which are critical to maintain the implementation rates and renewability of these systems in the cities
Evolution of physical training in football
En el ámbito del deporte, ha venido siendo demostrado, que uno de los factores más importantes para que el deportista pueda rendir
en las mejores condiciones es el de tener una
buena preparación física.
Independientemente del perfeccionamiento técnico, apoyo médico, nutrición, nuevos materiales, etc. La preparación física ha experimentado en los últimos años una evolución extraordinaria, tanto en cantidad como en calidad.
En las últimas décadas las ciencias del deporte han evolucionado enormemente, producto de ello son los avances aparecidos en la preparación física en el fútbol a todos sus niveles. En este artículo se analizan las principales tendencias que históricamente han venido empleándose para la mejora de las
diferentes cualidades físicas que implican la práctica de este deporte, con el objetivo de alcanzar el mejor rendimiento posible
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