217 research outputs found
Structural Evaluation of Bamboo Bike Frames: Experimental and Numerical Analysis
Construction of bicycles with bamboo frames has become an alternative to improve the quality of life of some communities, be friendly with the environment and be ecologically sustainable. However, the production of bike frames is made in an artisanal way and there are few antecedents that have proven their reliability. This work presents the evaluation and simulation of the mechanical behavior of bike frames made in bamboo. Three-points bending tests were performed using bamboo bars with similar dimensions to bike frames, and an equivalent elasticity modulus was determined and used as the input datum of a finite element model. A linear model material and beam elements were used to model the bike frame. Tests were performed using bike frames of bamboo applying loads greater than 7000 N, and the displacements were measured. The experimental displacements were used to calibrate the model, which consisted of modifying the rigidity of the connections until the displacements of the model fit near to 90%. The calibrated model was used for a fatigue simulation in order to predict the lifespan of the bike frame. Some technical values of bamboo bike frames were obtained so that these will allow them to define the technical characteristics of the product and guarantee their operating conditions
Family Dynamics and Personal Strengths among Dementia Caregivers in Argentina
This study examined whether healthier family dynamics were associated with higher personal strengths of resilience, sense of coherence, and optimism among dementia caregivers in Argentina. Caregivers are usually required to assist individuals with dementia, and family members have typically fulfilled that role. Personal strengths such as resilience, sense of coherence, and optimism have been shown to protect caregivers from some of the negative experiences of providing care, though the family-related variables associated with these personal strengths are largely unknown. Hierarchical multiple regressions investigated the extent to which family dynamics variables are associated with each of the caregiver personal strengths after controlling for demographic and caregiver characteristics. A sample of 105 caregivers from Argentina completed a set of questionnaires during a neurologist visit. Family dynamics explained 32% of the variance in resilience and 39% of the variance in sense of coherence. Greater family empathy and decreased family problems were uniquely associated with higher resilience. Greater communication and decreased family problems were uniquely associated with higher sense of coherence. Optimism was not found to be significantly associated with family dynamics. These results suggest that caregiver intervention research focused on the family may help improve caregiver personal strengths in Argentina and other Latin American countries
MMADHC Premature Termination Codons in the Pathogenesis of Cobalamin D Disorder: Potential of Translational Readthrough Reconstitution
Mutations in the MMADHC gene cause cobalamin D disorder (cblD), an autosomal recessive inborn disease with defects in intracellular cobalamin (cbl, vitamin B12) metabolism. CblD patients present methylmalonic aciduria (MMA), homocystinuria (HC), or combined MMA/HC, and usually suffer developmental delay and cognitive deficits. The most frequent MMADHC genetic alterations associated with disease generate MMADHC truncated proteins, in many cases due to mutations that create premature termination codons (PTC). In this study, we have performed a comprehensive and global characterization of MMADHC protein variants generated by all annotated MMADHC PTC mutations in cblD patients, and analyzed the potential of inducible translational PTC readthrough to reconstitute MMADHC biosynthesis. MMADHC protein truncation caused by disease-associated PTC differentially affected the alternative usage of translation initiation sites, protein abundance, and subcellular localization of MMADHC. Aminoglycoside compounds induced translational PTC readthrough of MMADHC truncated variants, allowing the biosynthesis of full-length MMADHC in a PTC-specific manner. Our results suggest that translational PTC readthrough-based interventions could complement current therapies for cblD patients carrying specific MMADHC PTC mutations.Financial support from Ikerbasque, The Basque Foundation for Science (R.P., J.C.A.-L., and J.M.C.); Ministerio de Economia, Industria y Competitividad (Spain) and FEDER (grant DPI2016-79874-R to J.C.A.-L. and J.M.C., grant SAF2016-79847-R to R.P.); Fundacion Mutua Madrilena (Spain) (grant AP169812018 to J.C.A.-L. and J.M.C). J.D.L.H. acknowledges the Biocruces Bizkaia Health Research Institute contract for Intensification of Research Activities. J.D.L.H. is a member of the European Reference Network for Rare Hereditary Metabolic Disorders (MetabERN)-Project ID No 739543. C.E.N-X. is the recipient of a Miguel Servet research contract from Instituto de Salud Carlos III (ISCIII, Spain) (CP20/00008). L.T. is the recipient of a predoctoral fellowship from Asociacion Espanola Contra el Cancer (AECC, Junta Provincial de Bizkaia, Spain). We thank to Javier Diez-Garcia (Microscopy core facility, Biocruces Bizkaia Health Research Institute) and to Gustavo Perez-Nanclares and Ana Belen de la Hoz (Genetics-Genomics core facility, Biocruces Bizkaia Health Research Institute) for their expert assistance with microscopy and DNA sequencing, respectivel
Marco legal de los riesgos profesionales y la salud ocupacional en colombia, siglo xx
Objetivo Analizar la normativa emitida en Colombia desde la perspectiva del derecho del trabajo, la seguridad social y la salud pública en el siglo XX, para identificar las concepciones en torno a la salud ocupacional y los riesgos profesionales, estableciendo las convergencias y diferencias que existen entre cada una de estas líneas y si responden o no a una visión complementaria.Método Investigación documental, mediante un análisis categorial temático de las reglamentaciones y estatutos promulgados en el siglo XX en Colombia, considerando el elemento o materia principal que se encarguen de regular relacionado con los riesgos profesionales o la salud ocupacional.Resultados Se construyó una periodización del desarrollo normativo en salud laboral en el país en el siglo XX, permitiendo evidenciar el predominio histórico de la visión del derecho social, que se concentra en la protección de los riesgos profesionales de los trabajadores dependientes, como una tendencia que se extiende hasta el Sistema General de Riesgos Laborales.Conclusiones Las etapas propuestas como eje ordenador de la normativa en riesgos profesionales y salud ocupacional posibilitan reconocer elementos trascendentales del contexto social, legal e institucional en el que emergieron tales reglamentaciones preocupadas por la salud de los trabajadores, advirtiéndose una tensión histórica entre las preceptivas dirigidas a la reparación y compensación de las contingencias relacionadas con el trabajo y aquellas directrices con una orientación preventiva
Spin-to-charge conversion by spin pumping in sputtered polycrystalline BiSe
Topological materials are of high interest due to the promise to obtain low
power and fast memory devices based on efficient spin-orbit torque switching or
spin-orbit magnetic state read-out. In particular, sputtered polycrystalline
BiSe is one of the materials with more potential for this purpose
since it is relatively easy to fabricate and has been reported to have a very
high spin Hall angle. We study the spin-to-charge conversion in
BiSe using the spin pumping technique coming from the ferromagnetic
resonance in a contiguous permalloy thin film. We put a special emphasis on the
interfacial properties of the system. Our results show that the spin Hall angle
of BiSe has an opposite sign to the one of Pt. The charge current
arising from the spin-to-charge conversion is, in contrast, lower than Pt by
more than one order of magnitude. We ascribe this to the interdiffusion of
BiSe and permalloy and the changes in chemical composition produced
by this effect, which is an intrinsic characteristic of the system and is not
considered in many other studies
Modified Wisconsin Card Sorting Test (M-WCST): Normative data for Spanish-speaking pediatric population
OBJECTIVE: To generate normative data for the Modified Wisconsin Card Sorting Test (M-WCST) in Spanish-speaking
pediatric populations.
METHOD: The sample consisted of 4,373 healthy children from nine countries in Latin America (Chile, Cuba, Ecuador,
Guatemala, Honduras, Mexico, Paraguay, Peru, and Puerto Rico) and Spain. Each participant was administered the M-WCST
as part of a larger neuropsychological battery. Number of categories, perseverative errors, and total error scores were normed
using multiple linear regressions and standard deviations of residual values. Age, age2, sex, and mean level of parental
education (MLPE) were included as predictors in the analyses.
RESULTS: The final multiple linear regression models indicated main effects for age on all scores, such that the number
of categories correct increased and total number of perseverative errors and total number of errors decrease linearly as a
function of age. Age2 had a significant effect in Chile, Cuba, Ecuador, and Spain for numbers of categories; a significant
effect for number of perseverative errors in Chile, Cuba, Mexico, and Spain; and a significant effect for number of total
errors in Chile, Cuba, Peru, and Spain. Models showed an effect for MLPE in Cuba (total errors), Ecuador (categories and
total errors), Mexico (all scores), Paraguay (perseverative errors and total error), and Spain (categories and total errors). Sex
affected number of total errors for Ecuador.
CONCLUSIONS: This is the largest Spanish-speaking pediatric normative study in the world, and it will allow neuropsychologists from these countries to have a more accurate way to interpret the M-WCST with pediatric populations
CONCIENTIZACIÓN AMBIENTAL SOBRE LOS GEI Y EL CAMBIO CLIMÁTICO EN EL INSTITUTO TECNOLÓGICO METROPOLITANO, INSTITUCIÓN UNIVERSITARIA (ITM)
La preocupación actual por las notables evidencias del cambio climático global está llevando a los países a mitigar sus principales causas: los gases efecto invernadero (GEI), a través de diferentes estrategias, entre ellas y haciendo un gran énfasis esta la educación ambiental. La huella de carbono es un indicador del impacto ambiental sobre la atmósfera, que cuantifica las diferentes emisiones de GEI, que se pueden estimar de manera aproximada haciendo uso de los aplicativos disponibles en la web. Se presentan en el presente artículo las principales campañas de educación ambiental y experiencias desarrolladas por el semillero de cultura, gestión e investigación ambiental “Cuida Tu Huella”, con relación a la Huella de Carbono en el Instituto Tecnológico Metropolitano (ITM). La estimación de la huella de carbono personal arrojó resultados de 4.22 y 3.87 ton CO2/año para los años 2011 y 2012 respectivamente, siendo aún más importante el impacto que se ha podido lograr en la comunidad académica, que trasciende el espacio geográfico de la Institución, ya que ha permitido lograr la concientización en cuanto a identificar las diferentes actividades que más producen GEI, transformando así los hábitos de vida por otros más ambientalmente sostenibles.
LivestockPlus: The sustainable intensification of forage-based agricultural systems to improve livelihoods and ecosystem services in the tropics
As global demand for livestock products (such as meat, milk, and eggs) is expected to double by 2050, necessary
increases to future production must be reconciled with negative environmental impacts that livestock cause. This
paper describes the LivestockPlus concept and demonstrates how the sowing of improved forages can lead to the
sustainable intensification of mixed crop–forage–livestock–tree systems in the tropics by producing multiple social,
economic, and environmental benefits. Sustainable intensification not only improves the productivity of tropical
forage-based systems but also reduces the ecological footprint of livestock production and generates a diversity of
ecosystem services (ES), such as improved soil quality and reduced erosion, sedimentation, and greenhouse gas
(GHG) emissions. Integrating improved grass and legume forages into mixed production systems (crop–livestock,
tree–livestock, crop–tree–livestock) can restore degraded lands and enhance system resilience to drought and
waterlogging associated with climate change. When properly managed tropical forages accumulate large amounts
of carbon in soil, fix atmospheric nitrogen (legumes), inhibit nitrification in soil and reduce nitrous oxide emissions
(grasses), and reduce GHG emissions per unit livestock product.
The LivestockPlus concept is defined as the sustainable intensification of forage-based systems, which is based
on three interrelated intensification processes: genetic intensification – the development and use of superior
grass and legume cultivars for increased livestock productivity; ecological intensification – the development and
application of improved farm and natural resource management practices; and socio-economic intensification
– the improvement of local and national institutions and policies, which enable refinements of technologies
and support their enduring use. Increases in livestock productivity will require coordinated efforts to develop
supportive government, non-government organization, and private sector policies that foster investments and
fair market compensation for both the products and ES provided. Effective research-for-development efforts that
promote agricultural and environmental benefits of forage-based systems can contribute towards implemention of
LivestockPlus across a variety of geographic, political, and socio-economic contexts
People with Disabilities and Other Forms of Vulnerability to the COVID-19 Pandemic: Study Protocol for a Scoping Review and Thematic Analysis
Objectives
To develop a protocol for a scoping review mapping as well as thematically analyzing the literature on the effect of, and responses to, the coronavirus disease 2019 (COVID-19) pandemic, focused on people with disabilities with other layers of individual vulnerability or social disadvantage.
Methods
We will search scientific databases (Medline/PubMed, Web of Science, Scopus, AgeLine, PsycINFO, CINAHL, ERIC) and preprint servers (MedRxiv, SocArXiv, PsyArXiv). Google searches, snowballing, and key-informant strategies were also used, including a focus on the gray literature (eg, official reports). Peer-reviewed and preprint publications will be covered in 6 languages, and the gray literature in English. Publications will be included if they address individuals with disabilities; the COVID-19 pandemic or subsequent socioeconomic or occupational effects; and individual or social vulnerabilities, including any form of discrimination, marginalization, or social disadvantage. Two independent reviewers will perform eligibility decisions and key data extractions. Beyond mapping the literature, the results will thematically analyze any disproportionate risks people with disabilities and other forms of vulnerability experience in terms of being infected by COVID-19, having severe health consequences, and facing negative socioeconomic effects. Actions taken or recommended to reduce identified inequalities will also be synthesized. Our entire research team, with diverse backgrounds, will be involved in the synthesis.
Conclusions
This review, which we plan to expedite, aims to inform policy makers, health authorities, disability advocates, and other stakeholders regarding the needs and ways to promote equity and disability-inclusive responses to the COVID-19 pandemic and the resultant socioeconomic shockwaves
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