25 research outputs found

    Patterns of enzymatic activity of cell wall-modifying enzymes during growth and ripening of apples

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    Fruit softening is thought to result from extensive cellwall modifications that occur during ripening. These modifications are the result, at least in part, of the activity of members of cell wall-modifying enzymes from the same families involved in the cell wall loosening which promote tissue extension and growth. In this work, the activities of a set of pectolytic and non-pectolytic cell wall-modifying enzymes, namely polygalacturonase (PG; endo-and exo-acting), pectin methylesterase (PME), pectate lyase (PL), b-galactosidase (b-Gal), a-l-arabinofuranosidase (AFase), endo-1,4-b-glucanase (EGase), xyloglucan endotransglycosylase (XET) and expansin, were monitored during growth and ripening of ‘Mondial Gala’ apple (Malus×domestica Borkh.) fruit. After optimisation of extraction protocols and standard activity assays, activity could be detected in all the assays, except for endo-PG. The overall results suggest that fruit growth and ripening are possibly coordinated by members of the same families of cell wall-modifying enzymes, although different isoforms may be involved in distinct developmental processes. Based on the trend of total activity measured in vitro using equal amounts of protein per developmental stage, the role of EGase seems to be more prominent during growth than during ripening, and XET activity is most important only after the fruit stopped growing and is maintained throughout ripening. b-Gal and AFase activities increased after harvest as the fruit became over-ripe. On the other hand, exo-PG, PL and expansin activities increase from that in unripe fruit to fruit at harvest but are maintained at similar levels thereafter, throughout the over-ripe stages. The patterns of activity observed are discussed in relation to published information about ripening of apples and to results reported using other species

    Inquiry in higher education for sustainable development: Crossing disciplinary knowledge boundaries

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    This paper aims to present the research results of the impact of a pedagogical approach on students, implemented as a part of the Doctoral Programme in Sustainability Science, which was designed following an innovative model at the University of Lisbon, Portugal. The main drivers include building a new body of interdisciplinary knowledge leading to the application of science to address real problems towards transdisciplinary education. We aimed to understand if a project work methodology proposed to students, based on an inquiry perspective and dealing with different dimensions of sustainable development, contributed to creating an interdisciplinary solution for a problem on sustainability challenged by food production and consumption, and also to understand if this methodological approach is perceived as important to their learning as professionals and citizens. Data were collected by direct observation, a questionnaire applied to the students, and students’ individual reflections. The results suggest great potential for an inquiry perspective in trying to solve a real problem. Students' proposals were realistic, viable, and complementary enough to collectively contribute in response to the global problem. The use of approaches acquired from different areas of knowledge was clear, and the project methodology was well understood. Students considered the experience very rewarding in terms of learning and contributing positively to their personal and professional development. This Doctoral programme is anchored in a progressive continuum encompassing holistic debates with a multidisciplinary team of professors in environments that promote interdisciplinary attitudes and new knowledge, and also project work aimed at guiding students to transdisciplinary learning, which constitutes an innovative form of dealing with the complex challenges created by the science of sustainability.info:eu-repo/semantics/publishedVersio

    The impact of COVID-19 on diet quality, food security and nutrition in low and middle income countries: a systematic review of the evidence

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    Background & Aims: The current global pandemic of Coronavirus (COVID-19), and measures adopted to reduce its spread, threaten the nutritional status of populations in Low- and middle-income countries (LMICs). Documenting how the COVID-19 affects diets, nutrition and food security can help generating evidence-informed recommendations for mitigating interventions and policies. Methods: We carried out a systematic literature review. A structure search strategy was applied in MEDLINE (Pubmed®), EMBASE®, Scopus® and Web of Science®. Grey literature was retrieved by screening a pre-set list of institutions involved in monitoring the impact of COVID-19 pandemic on nutrition and food security. The first search was done on 20th August 2020, and updated in mid-November 2020 and mid-January 2021. All research steps were described as recommended in the PRISMA statement. Results: Out of the 2085 references identified, thirty-five primary studies were included. In spite of their heterogeneity, studies converge to demonstrate a detrimental effect of COVID-19 pandemic and associated containment measures on diet quality and food insecurity. One of the major direct effects of COVID-19 on food and nutrition outcomes has been through its impact on employment, income generating activities and associated purchasing power. Other channels of impact, such as physical access, availability and affordability of food provided a heterogeneous picture and were assessed via binary and often simplistic questions. The impacts of COVID-19 manifested with various intensity degrees, duration and in different forms. Factors contributing to these variations between and within countries were: 1) timing, duration and stringency of national COVID-19 restriction measures and policies to mitigate their adverse impacts; 2) context specific food value chain responses to domestic and international containment measures; 3) differentiated impacts of restriction measures on different groups, along lines of gender, age, socio-economic status and employment conditions. Dietary changes and food insecurity manifested various intensity degrees, duration and in different forms between and within countries. Shorter value chains and traditional smallholder farms were somewhat more resilient in the face of COVID-19 pandemic. Additionally, the impact of the pandemic has been particularly adverse on women, individuals with a low socio-economic status, informal workers and young adults that relied on daily wages. Finally, there were heterogeneous government responses to curb the virus and to mitigate the damaging effects of the pandemic. It has been demonstrated that existing and well-functioning social protection programmes and public distribution of food can buffer the adverse effects on food insecurity. But social safety nets cannot be effective on their own and there is a need for broader food systems interventions and investments to support sustainable and inclusive food systems to holistic achieve food and nutrition security. Conclusion: In conclusion, the current economic and heath crisis impact diet quality and food security, and this raises concerns about long term impacts on access to and affordability of nutrient-rich, healthy diets and their health implications. Women and individuals with a low socio-economic are the most at risk of food insecurity. Social safety nets can be effective to protect them and must be urgently implemented. We advocate for improved data collection to identify vulnerable groups and measure how interventions are successful in protecting them

    COVID-19 and lockdown, as lived and felt by university students

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    © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).In the last 2 years, the COVID-19 pandemic has spread all over the world, forcing the closure of universities, among other unusual measures in recent history. (1) Background: This work is based on the study HOUSE-ULisbon, a survey carried out during the second confinement (March-May 2021) in Portugal with the collaboration of all the Faculties of the University of Lisbon (UL). The present work aims to explore gender differences in how first-year college students experienced and felt COVID-19 and the second confinement. (2) Methods: A questionnaire was carried out. In total, 976 university students (19.66 years (SD = 4.033); Min = 17 and Max = 65) from the first year of the UL were included, of which 69.5% (n = 678) were female, and 30.5% were male (n = 298). SPSS v. 26 was used for quantitative data and MAXQDA 2020 for qualitative data. (3) Results: Overall, students reported various symptoms of physical and mental discomfort (especially females). Statistically significant differences were found in the problems that could arise from the pandemic, such as the prevalence of higher anxiety and worries by females, and online gaming by males. In coping strategies, differences were found in leisure and family relationships, with greater difficulty on the female side. Social interaction was perceived as difficult or very difficult by both genders. As strategies for future pandemics, they highlighted a concerted effort between the government and media in the transmission of messages to the population, facilitating information, knowledge and adoption of protective behaviors. (4) Conclusions: These results are important data for activating or maintaining resources and services for first-year university students, who in some university institutions were supported during the pandemic by psychological, material (e.g., computers, internet), and financial support measures, which are now diminished or extinct. The impacts on their lives will certainly not be extinguished post-pandemic, and health, education, and public policy measures should be prioritized for this group. These results are important data for activating resources and services for students, informing health and education professionals, and supporting public policies.Ana Cerqueira—Foundation for Science and Technology (FCT) PhD Grant (SFRH/BD/148403/2019); Fábio Botelho Guedes—Foundation for Science and Technology (FCT) PhD Grant (SFRH/BD/148299/2019).info:eu-repo/semantics/publishedVersio
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