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  • Postdoctoral researchers at European universities: profiles, roles and institutional support structures
    Publication . Engels, Tim; Hasgall, Alexander; Peneoasu, Annamaria; Hanenberg, Peter
    Postdoctoral researchers are important contributors to European higher education, playing significant roles in research, but also in teaching and societal engagement. Despite their valuable contribution, the situation of postdoctoral researchers remains challenging in Europe as issues such as temporary or short-term contracts, high workloads and financial insecurity impact their work and mental health. In this context, many European universities are stepping up the support they provide at institutional level to shape highly skilled and well-rounded postdoctoral researchers, ready to explore a broad variety of job opportunities both inside and beyond academia. This report outlines the conclusions of the EUA-CDE Thematic Peer Group on “Profiles and institutional support for postdoctoral researchers”, established in 2023 to provide an overview of the current services and resources available at the postdoctoral level. With findings gathered from 28 universities in 16 European countries, this publication reflects the group’s discussions concerning the current state of play and the most pressing issues faced by postdoctoral researchers. This report addresses existing institutional support in place for the postdoctoral community, discusses new strategies, provides examples of good practices and suggests possible ways forward for European universities on how to improve the postdoctoral experience. It also serves as a source of reflection for institutions considering creating a more sustainable environment for this population and fostering their postdoctoral services and support.
    2024-03-11Report Open access Show more
  • O impacto dos influenciadores digitais na escolha de destinos turísticos por parte da Geração Z
    Publication . Santos, Joana Oliveira Pereira; Ribeiro, Nelson Costa
    A presente dissertação tem como objetivo perceber o impacto dos influenciadores digitais no processo de escolha de um destino turístico para os jovens da Geração Z. Para além disto visa também a compreender de que forma é que estes influenciadores digitais apresentam os diferentes destinos através das suas contas. A dissertação apresenta uma análise de conteúdo a duas contas do Instagram de influenciadores digitais relacionados com turismo. Esta análise debruçou-se sobre todas as viagens dos influenciadores realizadas em 2023, de forma a tentar perceber como é que estes apresentam os destinos. De seguida foi também realizado um inquérito por questionário aos jovens da Geração Z, utilizadores do Instagram e seguidores de influenciadores digitais relacionados com turismo. Este inquérito por questionário foi feito com o objetivo de perceber como estes indivíduos percecionam o impacto dos influenciadores digitais nas suas decisões sobre viagens. Com os resultados obtidos da análise de conteúdo foi possível perceber que os influenciadores digitais apostam fortemente na utilização de Reels para divulgar os seus conteúdos de viagens e utilizam sobretudo conteúdos de vídeo com música nas suas publicações. Para além disso, também têm preferência em aparecer nas publicações que fazem ao invés de apenas darem destaque à paisagem e aos locais. Já no que diz respeito aos resultados obtidos do inquérito por questionário, foi possível constatar que os inquiridos sentem que sofrem que a sua decisão de escolha de destinos turísticos é influenciada pelos conteúdos dos influenciadores que seguem no Instagram.
    2024-03-11Master thesis Restricted access Show more
  • Establishment of in vitro gastrointestinal models platform for human food and animal feed ingredients development
    Publication . Carvalho, Nelson Fernando Mota de; Madureira, Ana Raquel Mendes Ferreira Monteiro; Oliveira, Diana Luazi Matos de
    Globally, the human diet significantly relies on animal-derived products. The agri-food industry needs to optimize animal growth and performance to meet consumers demands, while reducing costs, ensuring product quality, and addressing sustainability and health concerns. Enhancing diets, through feed/food fortification with bioactive ingredients targeting gut microbiota is a promising strategy to promote the well-being and animal’s performance. Agro-industrial byproducts are potential sources of these bioactive ingredients, however, their effects and potential application on animal/human diets must be carefully evaluated. The main goal of this doctoral research was to create a platform of in vitro models that simulate the human and animal gastrointestinal tract (GIT), the GIOTA platform. Thus, models were implemented to assess and validate the impact of feed/food supplemented with bioactive ingredients on the gut microbiota, before resorting to in vivo trials. This supports the development of new products and promotes the inclusion of more sustainable ingredients, such as some of the byproducts tested in these models. The experimental work focused on 3 types of GIT: Human, Poultry and Bovine. In the first part, the preservation of human fecal inoculum was optimized, and the metabolic profile of colonic fermentations was compared between fresh and frozen inoculum. Storage at -20 oC with a 30% (v/v) glycerol solution allowed maintaining the viability of the inoculum for 90 days without affecting colonic fermentations. Furthermore, with the in vitro model already implemented, the impact of food matrices on microbiota modulation was evaluated. Skim milk (SKM) supplemented at 1% (w/v) by different well-known functional ingredients that modulate the gut microbiota were tested. The combination of SKM with fructo-oligosaccharides proved to be most beneficial for consumer’s health, promoting Lactobacillus, Bifidobacterium and Clostridium cluster IV, increasing the production of short-chain fatty acids, and reducing ammonia production. In second part, a poultry GIT in vitro model, specifically chickens, was designed to predict the effects of feed formulations on their microbiota. Two preservation methods of cecal inoculum were studied: (1) 5 % (v/v) dimethyl sulfoxide (DMSO) at -80 oC and (2) 30% (v/v) glycerol at -20 oC. Fresh and frozen inoculums were used in this model, and their fermentation profile were compared. The DMSO preservation method proved to be the most appropriate for cecal inoculum preservation for 90 days. Additionally, to validate the results of the in vitro model, a broiler chicken in vivo assay and the chicken in vitro model were performed, comparing the effect of incorporating in feed 1% (w/w) sugarcane bagasse lignin, a byproduct of the sugarcane industry. The tested supplementation, in the in vivo assay, had a positive impact on broiler chicken cecum, increasing the acetate and butyrate concentrations and reducing the presence of Enterobacteriaceae. The GIT model showed a similar trend in microbiota modulation of the in vivo assay, but still requires adjustments in inoculum preparation. In third part, to assess the impact of diet on the bovine intestinal microbiota’s, 2 in vitro models were developed, one for adult cow (ruminant) and another for calf (monogastric). Preservation studies of rumen and fecal inoculum from adult cows were also performed. In the adult cow model, ruminal and hindgut fermentations were performed with fresh and frozen inoculum, while in the calf model only hindgut fermentations were performed. Preservation at -80 oC was the condition that least affected inoculum’s bacterial viability and did not affect their fermentative capacity. Simultaneously, a calf in vivo assay and a calf model were conducted and compared on the evaluation of the effect of supplementing 1% (w/w) autolyzed spent yeast (AY) from farnesene production on milk replacer (MR). The AY supplementation, in the in vivo assay, had a positive impact on calf’s hindgut microbiota, increasing the presence of Bifidobacterium. However, this result was not observed in the model, which requires adjustments in the methodology associated with the digestion of liquid feed matrices. Scientific research and innovation play a crucial role in addressing modern challenges in the agri-food industry. The developed models serve as valuable and sustainable tools in evaluating the impact and validating the potential of new products of new products in the animal and human feeding industries.
    2024-03-11Doctoral thesis Embargoed access Show more
  • Global age-sex-specific mortality, life expectancy, and population estimates in 204 countries and territories and 811 subnational locations, 1950–2021, and the impact of the COVID-19 pandemic: a comprehensive demographic analysis for the Global Burden of Disease Study 2021
    Publication . GBD 2021 Demographics Collaborators; Bettencourt, Paulo J. G.
    Background Estimates of demographic metrics are crucial to assess levels and trends of population health outcomes. The profound impact of the COVID-19 pandemic on populations worldwide has underscored the need for timely estimates to understand this unprecedented event within the context of long-term population health trends. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 provides new demographic estimates for 204 countries and territories and 811 additional subnational locations from 1950 to 2021, with a particular emphasis on changes in mortality and life expectancy that occurred during the 2020–21 COVID-19 pandemic period. Methods 22 223 data sources from vital registration, sample registration, surveys, censuses, and other sources were used to estimate mortality, with a subset of these sources used exclusively to estimate excess mortality due to the COVID-19 pandemic. 2026 data sources were used for population estimation. Additional sources were used to estimate migration; the effects of the HIV epidemic; and demographic discontinuities due to conflicts, famines, natural disasters, and pandemics, which are used as inputs for estimating mortality and population. Spatiotemporal Gaussian process regression (ST-GPR) was used to generate under-5 mortality rates, which synthesised 30763 locationyears of vital registration and sample registration data, 1365 surveys and censuses, and 80 other sources. ST-GPR was also used to estimate adult mortality (between ages 15 and 59 years) based on information from 31 642 location-years of vital registration and sample registration data, 355 surveys and censuses, and 24 other sources. Estimates of child and adult mortality rates were then used to generate life tables with a relational model life table system. For countries with large HIV epidemics, life tables were adjusted using independent estimates of HIV-specific mortality generated via an epidemiological analysis of HIV prevalence surveys, antenatal clinic serosurveillance, and other data sources. Excess mortality due to the COVID-19 pandemic in 2020 and 2021 was determined by subtracting observed all-cause mortality (adjusted for late registration and mortality anomalies) from the mortality expected in the absence of the pandemic. Expected mortality was calculated based on historical trends using an ensemble of models. In locationyears where all-cause mortality data were unavailable, we estimated excess mortality rates using a regression model with covariates pertaining to the pandemic. Population size was computed using a Bayesian hierarchical cohort component model. Life expectancy was calculated using age-specific mortality rates and standard demographic methods. Uncertainty intervals (UIs) were calculated for every metric using the 25th and 975th ordered values from a 1000-draw posterior distribution. Findings Global all-cause mortality followed two distinct patterns over the study period: age-standardised mortality rates declined between 1950 and 2019 (a 62·8% [95% UI 60·5–65·1] decline), and increased during the COVID-19 pandemic period (2020–21; 5·1% [0·9–9·6] increase). In contrast with the overall reverse in mortality trends during the pandemic period, child mortality continued to decline, with 4·66 million (3·98–5·50) global deaths in children younger than 5 years in 2021 compared with 5·21 million (4·50–6·01) in 2019. An estimated 131 million (126–137) people died globally from all causes in 2020 and 2021 combined, of which 15·9 million (14·7–17·2) were due to the COVID-19 pandemic (measured by excess mortality, which includes deaths directly due to SARS-CoV-2 infection and those indirectly due to other social, economic, or behavioural changes associated with the pandemic). Excess mortality rates exceeded 150 deaths per 100 000 population during at least one year of the pandemic in 80 countries and territories, whereas 20 nations had a negative excess mortality rate in 2020 or 2021, indicating that all-cause mortality in these countries was lower during the pandemic than expected based on historical trends. Between 1950 and 2021, global life expectancy at birth increased by 22·7 years (20·8–24·8), from 49·0 years (46·7–51·3) to 71·7 years (70·9–72·5). Global life expectancy at birth declined by 1·6 years (1·0–2·2) between 2019 and 2021, reversing historical trends. An increase in life expectancy was only observed in 32 (15·7%) of 204 countries and territories between 2019 and 2021. The global population reached 7·89 billion (7·67–8·13) people in 2021, by which time 56 of 204 countries and territories had peaked and subsequently populations have declined. The largest proportion of population growth between 2020 and 2021 was in sub-Saharan Africa (39·5% [28·4–52·7]) and south Asia (26·3% [9·0–44·7]). From 2000 to 2021, the ratio of the population aged 65 years and older to the population aged younger than 15 years increased in 188 (92·2%) of 204 nations. Interpretation Global adult mortality rates markedly increased during the COVID-19 pandemic in 2020 and 2021, reversing past decreasing trends, while child mortality rates continued to decline, albeit more slowly than in earlier years. Although COVID-19 had a substantial impact on many demographic indicators during the first 2 years of the pandemic, overall global health progress over the 72 years evaluated has been profound, with considerable improvements in mortality and life expectancy. Additionally, we observed a deceleration of global population growth since 2017, despite steady or increasing growth in lower-income countries, combined with a continued global shift of population age structures towards older ages. These demographic changes will likely present future challenges to health systems, economies, and societies. The comprehensive demographic estimates reported here will enable researchers, policy makers, health practitioners, and other key stakeholders to better understand and address the profound changes that have occurred in the global health landscape following the first 2 years of the COVID-19 pandemic, and longer-term trends beyond the pandemic.
    2024-03-11Journal article Open access Show more