Abstract The essay analyses a recent ethnography on the repair and maintenance of motorcycles in Romania from the Second World War to the present day. Bearing in mind the very definition of the object, the analytical and conceptual premises of the anthropology of motorcycle culture, the methodological strategies that document it and some of the most significant particularities of the post-Soviet historical context and of “the post-repair society”, it is possible to rethink the apparently technical phenomenon of motorcycle mechanics as an authentic total social fact that modulates a set of geopolitical, economic, technical, identity, symbolic, aesthetic, age and gender variables. In addition, some lines of comparative exploration with other current studies on ethnomechanics, mobilities and particularly the contemporary dissemination of motorcycles in different cultural areas are proposed, which may shed light on the possible relational configurations between technology, environment and society.

Resumen Se analiza una etnografía reciente sobre la reparación y el mantenimiento de motocicletas en Rumania desde la Segunda Guerra Mundial a la actualidad. A partir del detalle de las premisas analíticas y conceptuales del estudio antropológico de la cultura motociclística, de los propios recortes del objeto, de las estrategias metodológicas para documentarlo y de algunas de las particularidades más significativas del escenario histórico de la modernidad postsoviética y “la sociedad de la post-reparación”, se argumenta que es posible repensar el fenómeno aparentemente técnico de la mecánica motociclística como un auténtico hecho social total que modula un set de variables geopolíticas, económicas, técnicas, identitarias, simbólicas, estéticas, etarias y de género. Finalmente, se proponen algunas líneas posibles de exploración comparativa con otros estudios actuales sobre etnomecánica, movilidades y en particular la difusión contemporánea de motocicletas en áreas culturales muy distintas entre sí, que echan luz sobre las configuraciones relacionales posibles entre tecnología, medioambiente y sociedad.

ABSTRACT Introduction: Three-dimensional printing is one of the technologies that promote change at an economic and social level, and one of the fundamental elements of industry 4.0. It has enormous potential for the future of medicine, establishing itself as a new paradigm. Despite its advantages, its use in our environment is incipient. Objective: To design and develop solutions based on three-dimensional technologies for the teaching and practice of biomedical sciences. Materials and methods: A technological development investigation was carried out between the Center for Assisted and Sustainable Manufacturing of the University of Matanzas and Matanzas University of Medical Sciences, between September 2019 and July 2022. The designs and fabrications were made from the acquisition of computed tomography images, or from a surface scanner, which were then processed, converted into Standard Tessellation Language format, printed, and post-processed. Virtual designs were developed using computer-aided design software. Results: Various solutions were developed including prototypes: biomodels for craniosynostosis repair and anatomical figures, custom cranial prosthesis mold, hand prosthesis, O2 line splitters, tissue scaffolds, syringe gun, face shields, breast prosthesis; autologous restoration mold and tissue expander. Conclusions: In all areas of application of this technology in medicine―except the printing of medicines, in the current context―, it is feasible to obtain solutions in the territory of Matanzas. It is therefore imperative that managers and the medical community in general, begin to acquire awareness, knowledge, and experience to ensure the optimal use of this technology.

RESUMEN Introducción: La impresión tridimensional es una de las tecnologías que promueve el cambio a nivel económico y social, y uno de los elementos fundamentales de la industria 4.0. Asimismo, constituye un enorme potencial para el futuro de la medicina, estableciéndose como un nuevo paradigma. A pesar de sus ventajas, su explotación en nuestro medio es incipiente. Objetivos: Diseñar y desarrollar soluciones basadas en tecnologías tridimensionales para la enseñanza y la práctica de las ciencias biomédicas. Materiales y métodos: Se realizó una investigación colaborativa, de desarrollo tecnológico entre el Centro de Fabricación Asistida y Sostenible de la Universidad de Matanzas y la Universidad de Ciencias Médicas de Matanzas, entre septiembre de 2019 y julio de 2022. Los diseños y fabricaciones se realizaron a partir de la adquisición de imágenes de tomografía computarizada, o desde un escáner de superficie, las que luego se procesaron, se convirtieron en formato Standard Tessellation Language, se imprimieron y posprocesaron. Los diseños virtuales se desarrollaron empleando un software de diseño asistido por computadora. Resultados: Se desarrollaron varias soluciones que incluyen varios prototipos: biomodelos para reparación de craneosinostosis y figuras anatómicas, molde de prótesis craneal personalizada, prótesis de mano, divisores de líneas de O2, andamios tisulares, pistola portajeringas, protectores faciales, prótesis de mama, molde para restauración autóloga y expansor tisular. Conclusiones: En todas las áreas de aplicación de esta tecnología en medicina―salvo en la impresión de medicamentos, en el contexto actual―, es factible obtener soluciones en el territorio de Matanzas. Es un imperativo, pues, que directivos y la comunidad médica en general, comiencen a adquirir conciencia, conocimientos y experiencias para garantizar la utilización óptima de esta tecnología.

Abstract To connect the protection of natural resources to economic development, environmental rehabilitation is a promising way to repair and compensate for impacts on biodiversity and ecosystem services. Here, we aimed to compare and select potential indicators for the success of different rehabilitating ecosystems to quantify gains in biodiversity and ecosystem services within the Impact Mitigation Hierarchy. We sampled nine environmental variables along rehabilitation chronosequences from rehabilitating (i) iron mining waste piles, (ii) sand quarries, and (iii) compensation areas in the Carajás National Forest. From that, we computed the rehabilitation status, i.e., the proportion of environmental enhancements compared to the overall rehabilitation trajectory, and statistically validated the indicators that best described the status. With a mean rehabilitation status for the oldest rehabilitation stages from waste piles, sand quarries, and compensation areas of 52, 71, and 74%, respectively, we confirmed that rehabilitation activities were able to generate considerable gains in biodiversity. In all the cases, the Shannon diversity, phylogenetic diversity and Leaf Area Index performed better than did the other indices, encouraging the increased use of these indices for upscale monitoring activities. Consistent indicators across distinct projects highlight the importance of maximizing tree diversity and canopy closure in rehabilitation projects to increase biodiversity gains within Impact Mitigation Hierarchy. development Here Hierarchy i (i piles ii (ii quarries iii (iii Forest ie e i.e. trajectory 52 71 74 74% respectively cases i.e 5 7

Resumo As medidas de contenção e repressão ao trabalho escravo são fundamentadas principalmente em remédios econômicos. Com efeito, é negligenciado o bem central a ser protegido pelo ordenamento jurídico nessas situações: a dignidade. Dado esse cenário, é por meio da tese de J. M. Bernstein (Torture and Dignity) sobre a possibilidade de uma ética negativa baseada no relato da vítima que este artigo se atém a investigar novos caminhos de observação deste crime, bem como identificar alternativas de reparação da confiança no mundo desses sobreviventes. Para isso, como objetivo geral, busca-se reconstruir a contribuição de Bernstein para a compreensão do relato como uma alternativa de reparo à ofensa à dignidade nos casos de trabalho escravo. Como objetivos específicos, este trabalho perpassa por três eixos de apreciação: analisar a aplicabilidade do conceito de agência de Bernstein à construção teórica basilar ao entendimento do trabalho análogo ao de escravo; compreender como a perda de confiança no mundo se situa na vida dos sobreviventes do trabalho escravo; e, por fim, estabelecer como uma teoria baseada no relato desses sobreviventes pode contribuir para o resgate da dignidade dessas pessoas. Como resultados alcançados, observou-se a necessidade de inserção do relato e da escuta terapêutica como formas de recuperação dignidade humana, bem como a compreensão mais humanizada do procedimento após o resgate a partir dessa teoria. econômicos efeito situações cenário J M Torture Dignity crime isso geral buscase busca específicos apreciação fim pessoas alcançados observouse observou humana

Abstract The measures to contain and repress slave labor are based mainly on economic remedies. Indeed, the central good to be protected by the legal system in these situations is neglected: dignity. Given this scenario, it is through J. M. Bernstein's thesis (Torture and Dignity) on the possibility of a negative ethics based on the victim's report that this article focuses on investigating new ways of observing this crime, as well as identifying alternatives for repairing the crime. confidence in the world of these survivors. For this, as a general objective, we seek to reconstruct Bernstein's contribution to the understanding of the report as an alternative to repair the offense to dignity in cases of work analogous to slavery. As specific objectives, this work runs through three axes of appreciation: to analyze the applicability of Bernstein's concept of agency to the basic theoretical construction to the understanding of slave work; understand how the loss of confidence in the world is situated in the lives of survivors of slavery; and, finally, to establish how a theory based on the reports of these survivors can contribute to the rescue of these people's dignity. As results achieved, it was observed the need to insert the report and therapeutic listening as ways of recovering human dignity, as well as a more humane understanding of the procedure after the rescue based on this theory. remedies Indeed neglected scenario J M Bernsteins Bernstein s Torture Dignity victims victim crime objective slavery objectives appreciation finally peoples people achieved

Resumo Os repair cafés tornaram-se um fenómeno comum na Holanda e em alguns outros países europeus. Nos repair cafés, proprietários de objetos quebrados e voluntários que se propõem a consertar os objetos se reúnem para tentar resgatar eletrodomésticos quebrados. Embora o seu efeito econômico seja insignificante, os repair cafés são um pequeno passo no sentido de alcançar uma economia circular porque motivam os seus visitantes a levar vidas mais sustentáveis. Ao prolongar o ciclo de vida dos objectos, ao recusar o pagamento e ao criticar os produtores que frustram a reparação através de um design impraticável, os clientes e voluntários desafiam o modo de produção capitalista. tornaramse tornaram europeus insignificante sustentáveis objectos impraticável capitalista

Abstract Repair cafés have become a common phenomenon in the Netherlands and some other European countries. In repair cafés, owners of broken objects and volunteer-repairers meet to try to salvage broken appliances. While their economic effect is negligible, repair cafés are a small step towards attaining a circular economy because they motivate their visitors to lead more sustainable lives. By extending the life-cycle of objects, by refusing payment and by criticizing producers who frustrate repair by impractical design, customers and volunteers challenge the capitalist mode of production. countries volunteerrepairers volunteer repairers appliances negligible lives lifecycle life cycle design production

Abstract Soybean are rich in functional nutrients such as protein, Essential amino acid, Polyunsaturated fatty acid, minerals, vitamins and dietary fibre which can help maintain optimal body weight, prevent Alzheimer and cardiovascular disease. At the same time, it also contains some anti-nutritional factors which have adverse effects on the digestion, absorption and utilization of nutrients. Cellular and metabolic events are induced by water absorption during seed germination. After absorbing water, soybean dry seeds begin to mobilize organelles and enzyme activities, repair and activate physiological and biochemical processes, and start basic metabolism. After that, by controlling the key factors of metabolism, the cells complete the process of material transformation, energy metabolism, ROS balance, cell wall acidification and looseness, hypocotyl elongation, etc. and finish germination. As a result, cell metabolism causes significant changes in proteins, lipids, sugars, vitamins and minerals, and increases in some beneficial functional nutritional factors for humans and animals, the other anti-nutritional factors decreased obviously, which greatly improved the taste quality and economic value of soybean. This paper introduced the germination physiology, functional nutrients and their metabolic pathways during soybean germination. This study has important reference value for the study of theory and practice technology of soybean germination. protein acid minerals weight disease time antinutritional anti digestion activities processes that transformation balance looseness elongation etc result proteins lipids sugars animals obviously physiology

RESUMO As redes de distribuição de água são projetadas para operar durante um longo período, porém, espera-se que sua capacidade se reduza ao longo do tempo. O grande conjunto de opções que podem ser aplicadas para melhorar sua capacidade, combinado com sua complexidade hidráulica e a busca da solução mais econômica, criam um problema difícil de resolver. Portanto, neste artigo são avaliados os benefícios hidráulicos e econômicos de três estratégias de reabilitação: limpeza de tubos, substituição de tubos e correção de vazamentos. Primeiramente, cada estratégia é avaliada individualmente, e em seguida avaliadas em conjunto em dois estudos de caso, utilizando a minimização dos custos através do algoritmo PSO. Primeiro é avaliada a relação entre o investimento e a redução do déficit de pressão, tentando identificar a melhor estratégia, e em que ponto os benefícios são saturados. Em seguida, é feita a otimização considerando a combinação das três técnicas de intervenção para verificar se há a priorização de alguma das técnicas, e se essa priorização está relacionada com seu desempenho individual. Em termos econômicos e hidráulicos, a substituição de tubos foi a melhor técnica de intervenção, seguida da limpeza de tubulações e do conserto de vazamentos. No caso da substituição, poucas intervenções são suficientes para melhorar significativamente a pressão. Além disso, foi observado que quando as técnicas de intervenção são combinadas, o algoritmo prioriza a soluções conjuntas. período porém esperase espera tempo econômica resolver Portanto reabilitação vazamentos Primeiramente individualmente PSO pressão saturados individual disso combinadas conjuntas

ABSTRACT Water distribution networks (WDNs) are designed to operate over a long period, however, it is expected that their capacity reduces over time. The large set of options that can be applied to improve their capacity, combined with their hydraulic complexity and the search for the most economical solution create a difficult problem to solve. Therefore, in this paper the hydraulic and economic benefits of three rehabilitation strategies: pipes cleaning, pipe replacement and leakage fixing. were evaluated individually first and then combined into two case studies, through a cost minimization using the PSO algorithm. Initially, the relation between the investment and the reduction in pressure deficit is analyzed for each alternative to identify the best strategy, and at which point the benefits are saturated. Then, an optimization considering the combination of the three intervention techniques is made to verify if there is a prioritization of any technique, and if it is related with the individual performance. in economic and hydraulic terms pipe replacement was the best intervention technique, followed by pipe cleaning and leak repair. For substitution, few interventions are sufficient to significantly improve the pressure. Moreover, it was observed that in the intervention - combined, the algorithm prioritizes joint solutions. WDNs (WDNs period however time solve Therefore strategies fixing studies Initially strategy saturated Then technique performance repair substitution Moreover solutions

Resumo: A mobilidade socioeconômica de negras e negros no Brasil sempre se constituiu em um desafio. Mesmo em períodos de mais estabilidade, com ganhos no campo econômico, esse grupo permanece sub-representado em grande parte dos indicadores sociais. O racismo e suas derivações alimentam as desigualdades no país, e superar esse fenômeno significa reparar o epistemicídio, restituir as desigualdades e corrigir as injustiças históricas sofridas por essa parcela da população. Resumo desafio estabilidade econômico subrepresentado sub representado sociais país epistemicídio população

Abstract: The socioeconomic mobility of black women and men in Brazil has always been a challenge. Even in periods of greater stability, with gains in the economic field, this group remains underrepresented in most social indicators. Racism and its derivations feed inequalities in the country and overcoming this phenomenon means repairing epistemicide, restoring inequalities and correcting the historical injustices suffered by this part of the population. Abstract challenge stability field indicators epistemicide population

PURPOSE OF THE STUDY: Considering the COVID-19 outbreak as the first post-digital era pandemic, the influence of tourism marketing on the travel motivation of the contemporary tourist may invariably be susceptible to the crisis-induced subjective safety perceptions of tourists. A discernible gap exists in empirical evidence of the paradigm shift in tourist behaviour due to the impact of the COVID-19 pandemic. The study explores the influence of South Africa's marketing profile on the intrinsic travel motives of domestic tourists as mediated by the perceived safety of travel and tourism activities during the pandemic DESIGN/METHODOLOGY/APPROACH: A cross-sectional deductive study was conducted. Data were generated via a novel self-administered online survey conducted by iFeedback. Data from the final valid sample of 427 domestic tourists were analysed primarily utilising exploratory and confirmatory factor, as well as mediation analyses FINDINGS: The empirical evidence extends the behavioural economic theory within tourism marketing by establishing a positive partial mediating effect of safety perceptions in the domestic destination marketing-travel motives nexus during the COVID-19 pandemic. The findings also corroborate the value of information symmetry via various marketing and non-marketing media in mitigating risk perceptions and promoting the safety of travel and tourism activities in South Africa RECOMMENDATIONS/VALUE: Key recommendations emanating from the study include maximising marketing spending on an integrated, multi-channel marketing strategy - prioritising mass crisis communications and recovery-oriented marketing while promoting a tourism value proposition that instils trust and confidence in the tourist that domestic travel and tourism activity is safe. To promote domestic tourism, it is also recommended that tourism practitioners develop bespoke domestic tourism products that innovate contact services, such as booking and check-in procedures, to adhere to contemporary health and safety protocols beyond the era of COVID-19 MANAGERIAL IMPLICATIONS: The study's findings have significant managerial implications for tourism marketing. First, there is a need to repair or re-imagine the image of South Africa as a domestic tourism destination. Second, there is an urgent need to socially re-engineer tourist behaviour via social marketing-oriented crisis and post-crisis communications. These managerial interventions will mitigate the perceived risk associated with domestic travel and tourism and safeguard tourists from the actual health-related risk JEL CLASSIFICATION: M31, D91, Z33, Z38

Resumen: Colombia, país diverso biológica y culturalmente, firmó un Acuerdo de Paz en el año 2016, acontecimiento sociopolítico que incidió en la planificación urbana desde una mirada holística, haciendo hincapié en el estudio de los espacios públicos como elementos clave de interacción social y ambiental. En Tunja (ciudad de estudio), más allá del proceso de numeración de parques urbanos y su área, no hay soportes investigativos ni administrativos que permitan orientar la toma de decisiones en torno a la planificación de estos espacios públicos para el bienestar de la comunidad, involucrando el concepto de sustentabilidad y su incidencia en el posconflicto. Bajo lo anterior, el artículo tiene como objetivo diagnosticar el estado de los parques urbanos de Tunja, bajo el enfoque sistémico de sustentabilidad en el pensamiento urbano, analizando el papel que ejercen como parte esencial del espacio público al ser instrumentos generadores de cohesión, memoria y reparación dentro de las dinámicas del posconflicto como fenómeno pluridimensional. La metodología, con carácter exploratoria, se concentró en la recolección de datos en campo y en clasificación y análisis en variables ambientales, sociales y económicas, buscando relaciones entre su diagnóstico y el tema de interés, el posconflicto. En consecuencia, se evidenció un déficit de áreas verdes per cápita (2,1 m2/ hab), vegetación, equipamiento y mala percepción social, factores que actúan como limitantes de uso, acceso e identidad del espacio público. Se concluye que los parques urbanos en Tunja no están actuando como espacios que, desde la sustentabilidad, aporten en el proceso de reparación e incorporación social de víctimas del conflicto armado en Colombia.

Abstract: Colombia, a biologically and culturally diverse country, signed a Peace Agreement in 2016, a socio-political event that impacts urban planning from a holistic perspective, emphasizing the study of public spaces as critical elements of social and environmental interaction. In Tunja (city of study), beyond the process of numbering urban parks and their area, there is no research or administrative support to guide decision-making regarding the planning of these spaces for the community's welfare, involving the concept of sustainability and its impact on the post-conflict. This article aims to diagnose the state of the urban parks of Tunja under the systemic approach of sustainability in urban thinking, analyzing the role they play as an essential part of public space to generate instruments of cohesion, memory, and repair within the dynamics of post-conflict as a multidimensional phenomenon. The exploratory methodology focused on field data collection, classification, and analysis of environmental, social, and economic variables, seeking relationships between their diagnosis and the topic of interest, the post-conflict. Consequently, a deficit in green area per capita (2,1 m2/inhabitant), vegetation, equipment, and poor social perception was evidenced; factors that act as limiting factors in the use, access, and identity of public space, thus concluding that the urban parks in Tunja are not acting as spaces that from a sustainability perspective can contribute to the process of reparation and social incorporation of victims of the armed conflict in Colombia.

ABSTRACT Introduction: Atrophic pseudarthrosis of the humeral diaphysis is a secondary bone defect and one of the most complex infrequent pathologies in Orthopedics, therefore, solving it is a challenge for specialists. Objective: To demonstrate that the Masquelet technique with non-vascularized fibular autograft is efficient in the repair of large bone defects, specifically in humeral atrophic pseudarthrosis. Case report: A 35-year-old patient with right humeral diaphysis fracture of the dominant limb is reported. She was operated on by open reduction and internal fixation; an atrophic pseudarthrosis of the humeral diaphysis was diagnosed and the Masquelet technique was applied with non-vascularized fibular autograft and bilateral iliac crest cancellous graft. Consolidation was achieved with good clinical and radiological results. Conclusions: The treatment of humeral atrophic pseudarthrosis using the Masquelet technique with non-vascularized fibular autograft and bilateral iliac crest cancellous graft is an efficient method due to its radiological clinical result, minimal morbidity and low economic cost.

RESUMEN Introducción: La pseudoartrosis atrófica de la diáfisis humeral constituye un defecto óseo secundario y una de las patologías infrecuentes más complejas de la Ortopedia, por tanto, solucionarla es un desafío para los especialistas. Objetivo: Demostrar que la técnica de Masquelet con autoinjerto peroneal no vascularizado es eficiente en la reparación de grandes defectos óseos, específicamente en la pseudoartrosis atrófica humeral. Presentación del caso: Paciente de 35 años con fractura de diáfisis humeral derecha del miembro dominante. Fue operada por reducción abierta y fijación interna; se diagnosticó una pseudoartrosis atrófica de diáfisis humeral y se aplicó la técnica de Masquelet con autoinjerto peroneal no vascularizado e injerto esponjoso de cresta ilíaca bilateral. Se logró la consolidación con buen resultado clínico y radiológico. Conclusiones: El tratamiento de la pseudoartrosis atrófica humeral mediante la técnica de Masquelet con autoinjerto peroneal no vascularizado e injerto esponjoso de cresta ilíaca bilateral es un método eficiente por su resultado clínico radiológico, su mínima morbilidad y bajo costo económico.

ABSTRACT The biological, social, economic and psychological impact caused by cleft lip leads to the application of new modifications in the surgical correction of its treatment techniques. The objective of this research was to evaluate the results of the Millard's rotation-advancement surgical technique modified by Mulliken in the correction of incomplete unilateral cleft lip in Matanzas. A longitudinal, prospective study was conducted at "Eliseo Noel Caamaño" Pediatric Teaching Hospital, in Matanzas between 2016 and 2018. The universe was made up of children under one year of age diagnosed with incomplete unilateral cleft lip, who come to the Maxillofacial Surgery consultation of this hospital, in the period in which the investigation was carried out and in whom, Millard 's rotation-advancement surgical technique modified by Mulliken was used for their treatment. We worked with the entire universe. Descriptive statistics was used. The patients underwent surgery between 5 and 9 months, white skin color (75%) and male gender (75%) predominated. Labial height and heminasal width increased more on the healthy side than on the cleft side. One year after the intervention, the transverse width grew more on the cleft side than on the healthy side in two of the cases, and there was also a difference greater than 1 mm in the vermilion height. Mirror-image nasolabial symmetry was achieved on the healthy side in all variables, except for vermilion height in two cases.

RESUMEN El impacto biológico, social, económico y psicológico que acarrea la fisura labial conlleva a aplicar nuevas modificaciones en la corrección quirúrgica de sus técnicas de tratamiento. El objetivo de esta investigación fue evaluar los resultados de la técnica quirúrgica de Rotación y Avance de Millard modificada por Mulliken en la corrección de la fisura labial unilateral incompleta en Matanzas. Se realizó un estudio de casos, longitudinal, prospectivo en el Hospital Docente Pediátrico «Eliseo Noel Caamaño» de Matanzas, entre 2016 y 2018. El universo estuvo constituido por menores de un año diagnosticados de fisura labial unilateral incompleta, que asistieron a la consulta de Cirugía Maxilofacial de dicho hospital, en el período en que se realizó la investigación y en los que para su tratamiento se empleó la técnica de Rotación y Avance de Millard modificada por Mulliken. Se trabajó con la totalidad del universo. Se utilizó estadística descriptiva. Los pacientes fueron intervenidos entre los 5 y 9 meses, predominó el color de piel blanca (75 %) y el sexo masculino (75 %). La altura labial y el ancho heminasal aumentaron más en el lado sano que en el fisurado. Al año de la intervención en el lado fisurado creció más el ancho transversal que en el sano en dos de los casos y también existió una diferencia mayor de 1 mm en la altura del bermellón. Se logró alcanzar simetría nasolabial en espejo del lado sano en todas las variables, excepto en la altura del bermellón en dos casos.

RESUMEN El Consejo de Estado ha desarrollado la regla conforme a la cual todas las reclamaciones que emanen del desequilibrio económico del contrato estatal deben hacerse al momento de suscribir documentos tales como prórrogas, suspensiones, contratos adicionales u otrosíes. De no ser así, se finiquitan los asuntos pendientes para las partes, no siendo posible discutir posteriormente hechos anteriores, por resultar contrario al principio de la buena fe y a los actos propios. Se pretende analizar la restricción en la forma de aplicar el principio de la buena fe, pues al privilegiarse escenarios concretos de reclamación por desequilibrios económicos se disminuye la posibilidad de lograr el reajuste del contrato y la consecuente reparación de un daño.

ABSTRACT The Colombian State Council has developed the rule whereby every single claim based on the economic unbalance of public contracts must be made by the contractor at the precise moment of suscribing contractual documents such as extensions, suspensions, additions or amendments. If not, pending issues between the parties are deemed to be solved, and the contractor is banned from filing any claim in the future based on past circumstances, for doing so would violate the principle of good faith and the doctrine of one's own acts. Taking this into account, this paper seeks to analyze the way in which the principle good faith can be applied, because by privileging certain sceneries of economic, the State Council is in fact reducing the likelihood of obtaining the adjustment of the contract and the repair of the damage inflicted on the contractor.

Abstract Repair and maintenance activities are studied as a key sector for the transition to the circular economy, due to their economic and social importance and their role in prolonging the life of goods, reducing the consumption of new resources and waste generation. An empirical analysis of the repair and maintenance sector in Mexico is carried out, highlighting its structural specificities compared to the rest of the economic activities and also its own internal heterogeneity. The small size of the firms, the labour-intensive nature, the type of employment and the cost structure allow us to identify their social and environmental potential, but also the barriers and limitations compared to the sectors of production and sale of new goods. This analysis provides the basis for the further design of policies to boost their role in the transition to a circular economy.

Resumo Se estudian las actividades de reparación y mantenimiento como sector clave para la transición a la economía circular, por su importancia económica y social y por su papel en la prolongación de la vida de los bienes, la reducción del consumo de nuevos recursos y de generación de residuos. Se lleva a cabo un análisis empírico del sector de reparación y mantenimiento en México, destacando sus especificidades estructurales frente al resto de las actividades económicas y también la propia heterogeneidad interna. El tamaño reducido de las empresas, el carácter intensivo en mano de obra, el tipo de empleo y la estructura de costes permite identificar sus potencialidades sociales y ambientales, pero también las barreras y limitaciones frente a los sectores de producción y venta de bienes nuevos. Este análisis sienta las bases para el ulterior diseño de políticas para impulsar su papel en la transición hacia una economía circular.

ABSTRACT More than half a million electric bicycles, motorcycles and tricycles are in circulation in Cuba, 57,924 of them assembled in Cuban factories: 55,786 at Minerva (80 bicycles, 80 motorcycles and 82 tricycles); 1091 at Narciso López Roselló (222 bicycles, 539 motorcycles and 330 tricycles); 1047 at Vedca (217 bicycles, 427 motorcycles and 403 tricycles). Fires on electric motorcycles have become a growing phenomenon in the country. In 2020 there were 1.6 fires as a daily average, and in 2021 this figure rose to 2.1 with economic losses and human lives, being necessary to work with drivers and with the personnel working in maintenance and repair to mitigate this problem. A description of the batteries with their control device, the controller, the engine and the battery charger is made and a set of recommendations or good practices related to the elements responsible for most of the accidents occurred is presented.

RESUMEN En Cuba están circulando más de medio millón de bicicletas, motos y triciclos eléctricos, 57 mil 924 ensamblados en fábricas cubanas: en Minerva 55 mil 786 (80 bicicletas, 80 motos y 82 triciclos); en Narciso López Roselló 1091 (222 bicicletas, 539 motos y 330 triciclos); en Vedca 1047 (217 bicicletas, 427 motos y 403 triciclos). Los incendios en las motos eléctricas se han convertido en un fenómeno creciente en el país. En 2020 se produjeron 1,6 incendios como promedio diario, y en 2021 esta cifra se elevó hasta 2,1 con pérdidas económicas y de vidas humanas, siendo necesario trabajar con los conductores y con el personal que trabaja en mantenimiento y reparación para mitigar este problema. Se realiza una descripción de las baterías con su dispositivo de control, el controlador, el motor y el cargador de batería y se presenta un conjunto de recomendaciones o buenas prácticas relacionadas con los elementos responsables de la mayoría de los accidentes ocurridos.