Internships for Higher Education Students to Promote the Local Sustainability of Rural Places

Sustainability and population have a complex relationship. Popular versions of the first are usually based on the premise of reducing the population. However, in some remote rural areas with a low density, this condition needs to be reconsidered, as it would put the viability of the local community at risk and lead to environmental, economic and, above all, social losses. Although repopulation is impossible, since remote rural areas have an ageing demographic structure and an extremely low fertility rate, we can propose the regeneration of their human, social and relational capital by attracting talent and commitment. To achieve this, the Desafio Programme (Rural Erasmus) enables university students to do internships in companies and institutions in sparsely populated areas, living alongside their residents. Despite being an experimental policy with a narrow scope in statistical terms, the Desafio Programme is an inspiring experience supported by those who have participated in it and contributes to the social and economic regeneration of areas in decline. This is a practical case of applying a sustainable strategy to a rural area in crisis, which can be transferred to many other countries facing a similar problem

Chagas disease reactivation in a heart transplant patient infected by domestic Trypanosoma cruzi discrete typing unit I (TcIDOM)

Background Trypanosoma cruzi, causative agent of Chagas disease, displays high intraspecific genetic diversity: six genetic lineages or discrete typing units (DTUs) are currently recognized, termed TcI through TcVI. Each DTU presents a particular distribution pattern across the Americas, and is loosely associated with different transmission cycles and hosts. Several DTUs are known to circulate in Central America. It has been previously suggested that TcI infection is benign and does not lead to chronic chagasic cardiomyopathy (CCC). Findings In this study, we genotyped T. cruzi parasites circulating in the blood and from explanted cardiac tissue of an El Salvadorian patient who developed reactivation Chagas disease while on immunosuppressive medications after undergoing heart transplant in the U.S. as treatment for end-stage CCC. Parasite typing was performed through molecular methods (restriction fragment length polymorphism of polymerase reaction chain amplified products, microsatellite typing, maxicircle sequence typing and low-stringency single primer PCR, [LSSP-PCR]) as well as lineage-specific serology. We show that the parasites infecting the patient belong to the TcI DTU exclusively. Our data indicate that the parasites isolated from the patient belong to a genotype frequently associated with human infection throughout the Americas (TcI DOM ). Conclusions Our results constitute compelling evidence in support of TcI DTU’s ability to cause end-stage CCC and help dispel any residual bias that infection with this lineage is benign, pointing to the need for increased surveillance for dissemination of this genotype in endemic regions, the USA and globally

Fibre-reinforced polymer strengthening of substandard lap-spliced reinforced concrete members: A comprehensive survey

Externally bonded Fibre Reinforced Polymer (FRP) confinement is extensively used to improve the bond strength of substandard lap spliced steel bars embedded in reinforced concrete (RC) components. However, the test results from bond tests on such bond-deficient components are not fully conclusive, which is reflected in the few design guidelines available for FRP strengthening. For the first time, this article presents a comprehensive survey on FRP strengthening of substandard lap-spliced RC members, with emphasis on the adopted experimental methodologies and analytical approaches developed to assess the effectiveness of FRP in controlling bond-splitting failures. The main findings and shortcomings of previous investigations are critically discussed and further research needs are identified. This review contributes towards the harmonisation of testing procedures so as to facilitate the development of more accurate predictive models, thus leading to more cost-effective strengthening interventions

Bayes factor between Student t and Gaussian mixed models within an animal breeding context

[EN] The implementation of Student t mixed models in animal breeding has been suggested as a useful statistical tool to effectively mute the impact of preferential treatment or other sources of outliers in field data. Nevertheless, these additional sources of variation are undeclared and we do not know whether a Student t mixed model is required or if a standard, and less parameterized, Gaussian mixed model would be sufficient to serve the intended purpose. Within this context, our aim was to develop the Bayes factor between two nested models that only differed in a bounded variable in order to easily compare a Student t and a Gaussian mixed model. It is important to highlight that the Student t density converges to a Gaussian process when degrees of freedom tend to infinity. The two models can then be viewed as nested models that differ in terms of degrees of freedom. The Bayes factor can be easily calculated from the output of a Markov chain Monte Carlo sampling of the complex model (Student t mixed model). The performance of this Bayes factor was tested under simulation and on a real dataset, using the deviation information criterion (DIC) as the standard reference criterion. The two statistical tools showed similar trends along the parameter space, although the Bayes factor appeared to be the more conservative. There was considerable evidence favoring the Student t mixed model for data sets simulated under Student t processes with limited degrees of freedom, and moderate advantages associated with using the Gaussian mixed model when working with datasets simulated with 50 or more degrees of freedom. For the analysis of real data (weight of Pietrain pigs at six months), both the Bayes factor and DIC slightly favored the Student t mixed model, with there being a reduced incidence of outlier individuals in this population.The authors are indebted to Dr. J.L. Noguera and COPAGA for field data on pig weight at six months, and to Dr. J. Piedrafita and Dr. G. Caja for providingadditional field data sets during preliminary tests of the Bayes factor. The research contract of J. Casellas was partially financed by Spain s Ministerio de Educación y Ciencia (Programa Juan de la Cierva).Casellas, J.; Ibáñez-Escriche, N.; Garcia-Cortes, L.; Varona, L. (2008). Bayes factor between Student t and Gaussian mixed models within an animal breeding context. Genetics Selection Evolution. 40(4):395-413. https://doi.org/10.1051/gse:2008007S39541340

Development of engineering design tools to help reduce apple bruising

A large percentage of apples are wasted each year due to damage such as bruising. The apple journey from orchard to supermarket is very complex and apples are subjected to a variety of static and dynamic loads that could result in this damage occurring. The main aim of this work was to carry out numerical modelling to develop a design tool that can be used to optimise the design of harvesting and sorting equipment and packaging media to reduce the likelihood of apple bruise formation resulting from impact loads. An experimental study, along with analytical calculations, varying apple drop heights and counterface material properties, were used to provide data to validate the numerical modelling. Good correlation was seen between the models and experiments and this approach combined with previous work on static modelling should provide a comprehensive design tool for reducing the likelihood of apple bruising occurring

Characterising pressure and bruising in apple fruit

A large percentage of apples are wasted each year due to damage such as bruising. The apple journey from orchard to supermarket is very complex and apples are subjected to a variety of static and dynamic loads that could result in this damage occurring. The aim of this work was to use a novel ultrasonic technique to study apple contact areas and stresses under static loading that may occur, for example, in bulk storage bins used during harvesting. These results were used to identify load thresholds above which unacceptable damage occurs. They were also used to validate output from a finite element model, which will ultimately be developed into a packaging design tool to help reduce the likelihood of apple damage occurring

TESTING PROTOCOL DEVELOPMENT FOR FRACTURE TOUGHNESS OF PARTS BUILT WITH BIG AREA ADDITIVE MANUFACTURING

Mechanical testing of additively manufactured parts has largely relied on existing standards developed for traditional manufacturing. While this approach leverages the investment made on current standards development, it inaccurately assumes that mechanical response of AM parts is identical to that of parts manufactured through traditional processes. When considering thermoplastic, material extrusion AM, differences in response can be attributed to an AM part’s inherent inhomogeneity caused by porosity, interlayer zones, and surface texture. Additionally, interlayer bonding of parts printed with large-scale AM is difficult to adequately assess as much testing is done such that stress is distributed across many layer interfaces; therefore, the lack of AM-specific standard to assess interlayer bonding is a significant research gap. To quantify interlayer bonding via fracture toughness, double cantilever beam (DCB) testing has been used for some AM materials, and DCB has been generally used for a variety of materials including metal, wood, and laminates. Mode I DCB testing was performed on thermoplastic matrix composites printed with Big Area Additive Manufacturing (BAAM). Of particular interest was the crack shape and deflection speed during testing. A modernization of the testing process was proposed using visual processing of a recording of the crack propagation to get more accurate calculations. Results discuss the differences when using two crack types and three deflection speeds.Mechanical Engineerin