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Didactic videos have proven to be particularly beneficial for Science, Technology, Engineering and Mathematics (STEM) education challenges. This is due to their contribution to the reduction of the intrinsic cognitive load, as well as fostering connections among subjects to promote generative processing. This fact, together with the wide presence of STEM dissemination videos on YouTube, creates an opportunity both for teachers to focus on dissemination channels to acquire quality materials, and for content creators to develop specific videos aiming to serve as pedagogical aid. Aligned with such reasoning, this paper intends to evaluate the use and performance of a STEM YouTube channel that already publishes didactic videos categorized by intentionality into dissemination or educational. Using owners' data, the channel has been analyzed, considering a six-year extension period, from 2017 to 2022, and distinguishing between the two categories of contents. This dual intention of the channel allows to evaluate the educational use of dissemination channels, compared to their use for curiosity satisfaction. Through Mann-Whitney U and correlation analyses, the main channels' metrics have been analyzed in terms of awareness (i.e., impressions, views, or subscribers), use (view duration) and interaction (comments, shares, likes or dislikes). Significant differences have been found in the performance of educational and dissemination contents, such as in views (p < 0.001), average view duration (p = 0.044) and likes (p < 0.001). Additionally, video length optimization has been found as a determining parameter influencing video performance, being educational videos more sensitive to this metric than dissemination videos. This study has shown that a STEM YouTube channel of these characteristics can benefit from publishing videos aiming to a pedagogical purpose, increasing its use compared with other STEM dissemination channels only aiming to an entertainment purpose. Additionally, this study supports previous findings that video length optimization is a determinant characteristic for audience retention rate.
RESUMO
INTRODUCTION: Acute rejection has been identified as the main cause of renal graft dysfunction during the first year after transplantation; it is associated with chronic structural and functional damage, which causes loss of graft and decrease in patient survival. MATERIAL AND METHODS: We performed a retrospective and descriptive research consisting in a review of the final reports of biopsies performed due to renal graft dysfunction during the postransplant period. Patients included were transplanted at the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán (INCMNSZ) from January 2007 to December 2011. RESULTS: A total number of 223 patients underwent renal transplantation during the period considered for this study purpose, 222 biopsies were performed due to renal graft dysfunction in 118 patients (52.9%). 74.5% of patients developed graft dysfunction in the first year after transplantation. The main histopathological findings reported were immunologic events in both living donor (LDRTR) and deceased donor renal transplant recipients (DDRTR), borderline changes were the most common diagnosis. The median time to detect immune events as cause of dysfunction was shorter for DDRTR and they tend to occur in the first 4 months after transplantation. CONCLUSION: We observed an incidence of 11.8% for acute rejection in the first year after transplantation for LDRTR and 17.4% for DDRTR. Further studies are needed to determine the causes of immunological events and their implications in the evolution of renal graft and patient's survival.
