http://www.repositorio.uem.mz/handle258/88 2026-04-23T07:10:15Z http://www.repositorio.uem.mz/handle258/1568 Title: Biological control of water lettuce, Pistia stratiotes L., facilitates macroinvertebrate biodiversity recovery: a mesocosm study Authors: Coetzee, J. A.; Langa, S. D. F.; Motitsoe, S. N.; Hill, M. P. Abstract: Floating aquatic weed infestations have negative socio-economic and environmental conse- quences to the ecosystems they invade. Despite the long history of invasion by macrophytes, only a few studies focus on their impacts on biodiversity, while the ecological benefits of biological control pro- grammes against these species have been poorly quantified. We investigated the process of biotic homogenization following invasion by Pistia stra- tiotes on aquatic biodiversity, and recovery provided by biological control of this weed. Biotic homoge-nization is the increased similarity of biota as a result of introductions of non-native species. The study quantified the effect of P. stratiotes, and its biological control through the introduction of the weevil, Neo- hydronomus affinis on recruitment of benthic macroin- vertebrates to artificial substrates. Mats of P. stratiotes altered the community composition and reduced diversity of benthic macroinvertebrates in comparison to an uninvaded control. However, reduction in percentage cover of the weed through biological control resulted in a significant increase in dissolved oxygen, and recovery of the benthic macroinvertebrate community that was comparable to the uninvaded state. This highlights the process of homogenization by an invasive macrophyte, providing a justification for sustained ecological and restoration efforts in the biological control of P. stratiotes where this plant is problematic 2020-08-03T00:00:00Z http://www.repositorio.uem.mz/handle258/1567 Title: Enriching perspectives: experienced ecosystem services in rural Mozambique and the importance of a gendered livelihood approach to resist reductionist analyses of local culture Authors: Porsani, Juliana; Börjeson, Lowe; Lalander, Rickard; Lehtilä, Kari; Martins, Angelina R. O. Abstract: Based on a case study from rural Mozambique, we stress that ecosystem services research may be enriched through gendered livelihood approaches, particularly in terms of experienced ecosystem services. Ecosystem services studies have been accused of being gender blind. We argue for the value of open narratives that are attentive to the gender dynamics underpinning the production and reproduction of livelihoods. By focusing on the experienced gender dimension of ecosystem services, livelihood perspectives fulfill the normative role of providing a people-centered means to assess the values of the environment “from below” and can therefore constitute an entry point to a holistic understanding of by whom, how, when, and why the environment is experienced as valuable. Our findings stress the dynamism and plurality of experienced ecosystem services (i.e., they vary across groups and time and cross-cut material and immaterial dimensions), as well as the asymmetrical gendered and fundamentally cultural relations that they enable. Accounting for the experienced gender dimension of ecosystem services is critical to contextualize the environment in people’s lifeworlds and to make understandings of ecosystem services representative of, and instrumental to, people’s voices and agendas. We show how such enriched, diverse, bottom-up ecosystem services perspectives form an essential foundation (together with ecological research) for resisting applications of reductionist top-down categories assumed to represent general local values 2020-01-01T00:00:00Z http://www.repositorio.uem.mz/handle258/1566 Title: Phytochemical analysis and in vitro antioxidant and antimicrobial activities of hydroalcoholic extracts of the leaves of Salacia kraussii Authors: Zimila, Hercílio E.; Matsinhe, Albertina L.; Malayika, Emma; Sulemane, Átifa I.; Saete, Vanina N.C.; Rugunate, Saquina C.; Cumbane, Paulo J.; Magaia, Isabel; Munyemana, François Abstract: O presente trabalho teve como objetivo identificar os compostos bioativos e determinar as atividades antioxidante e antimicrobiana in vitro do extrato hidroetanólico das folhas de S. kraussii. A análise fitoquímica foi realizada por cromatografia gasosa-espectrometria de massa (GC-MS) e métodos colorimétricos clássicos. Método de Folin-Ciocalteu, precipitação com cloreto de alumínio e precipitação com caseína foram empregados para quantificação de fenóis, flavonóides e taninos totais, respectivamente. A atividade antioxidante foi estimada por ensaios de eliminação de DPPH, fosfomolibdato (TAC), eliminação de radicais ABTS e redução de potência (FRAP-1 e FRAP-2). A atividade antimicrobiana foi determinada pelo método de difusão em disco contra Escherichia coli, Staphylococcus aureus, Proteus mirabilis, Klebsiella pneumoniae e Candida albicans. Os testes fitoquímicos revelaram a presença de flavonóides, quinonas, alcalóides, esteróides, taninos e saponinas. A análise GC-MS identificou 17 compostos biologicamente importantes pertencentes a diferentes classes, incluindo ácidos graxos, carboidratos e terpenóides. O extrato apresentou teor relativamente baixo de fenóis totais, taninos e flavonóides de 5,00 mgEAG g-1, 0,08 mgEAT g-1 e 0,67 ± 0,29 mgEQ g-1, respectivamente. Seu potencial antioxidante foi consideravelmente mais forte que o das outras Salacia sp. com valores de EC50 de 64,28 ± 0,01, 36,44 ± 0,67, 35,78 ± 0,09, 33,91 ± 0,12 e 2,22 ± 0,25 μg mL-1 conforme medido pelos ensaios de eliminação de radicais FRAP-1, TAC, DPPH, FRAP-2 e ABTS, respectivamente . Em relação à atividade antimicrobiana, o extrato inibiu o crescimento de todos os organismos teste com concentrações inibitórias mínimas de 125 μg mL–1 e 250 μg mL–1 para bactérias e fungos, respectivamente. Este estudo perspicaz é um passo significativo para a exploração das folhas de S. kraussii como uma fonte barata de agentes antimicrobianos de amplo espectro(TRADUÇÃO NOSSA) 2020-11-30T00:00:00Z http://www.repositorio.uem.mz/handle258/1146 Title: The ocean as a source of renewable energy in sub- Saharan Africa: sources, potential, sustainability and challenges Authors: Sitoe, Alberto Filimão; Hoguane, António Mubango; Haddout, Soufiane Abstract: The present paper examines, based on literature review and data from Africa Energy Outlook 2019, the feasibility of adoption of renewable energy from the ocean for socioeconomic development in sub-Saharan Africa, given the enormous potential the region has for ocean-based sources of energy. The study concludes that mini tidal power plants and salt gradient power are the ocean energy sources most suitable for coastal development. It recommends a gradual reduction in subsidies of fossil fuel-based energy sources in favour of support to renewable energy, building human resources and technical capacity, the establishment of smart partnerships and mobilisation of resources for an effective promotion of ocean renewable energy. It recommends further, that community engagement is needed to assure ownership and acceptance. 2023-04-29T00:00:00Z