Browsing by Issue Date, starting with "2021-01"
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- Prevalence and drivers of poison use by South African commercial farmers and perceptions of alternative livestock protection measuresPublication . Brink, Christiaan Willem; Thomson, Robert Leslie; Amar, Arjun; Girardello, Marco; Santangeli, AndreaThe use of poison to eliminate predators is causing African vulture populations to collapse. To understand the prevalence and motivations of this practice we conducted an extensive survey with South African commercial farmers. Using a specialised questioning technique and ad hoc quantitative methods we found that an estimated 22% and 31% of farmers used poison over a 1-year and 5-year period, respectively. Poison use hotspots generally coincided with small stock farming areas. The strongest predictor of poison use was whether farmers believed the practice to be common amongst their peers. Our results suggest that farmers' attitudes to vultures are primarily positive, and farmers are less likely to use poisons if they frequently encounter vultures on their farm. Overall, our findings provide an understanding on poison use that provides leverage points to change farmers' behaviour and help avert the African vulture crisis and possible cascading ecosystem impacts.
- Exotic ladybirds for biological control of herbivorous insects : a reviewPublication . Rondoni, Gabriele; Borges, Isabel; Collatz, Jana; Conti, Eric; Costamagna, Alejandro C.; Dumont, François; Evans, Edward W.; Grez, Audrey A.; Howe, Andy G.; Lucas, Éric; Maisonhaute, Julie‐Éléonore; Soares, António O.; Zaviezo, Tania; Cock, Matthew J. W.Since the late 19th century, exotic ladybirds (Coleoptera: Coccinellidae) have been used extensively for suppressing herbivorous insects of economic importance. In recent decades, the introduction of non-native biological control (BC) agents has been greatly limited due to the awareness of the potential non-target effects of introductions. Nonetheless, recent episodes of biological invasions of economically important pests have raised the need to carefully consider whether the expected benefits of pest control go beyond the possible environmental risks of introduction. To better understand the factors that contributed to successful BC programs, here we review the literature behind classical and augmentative BC using exotic ladybirds. Additionally, by means of case studies, we discuss the BC efficacy of selected exotic species, e.g., Coccinella septempunctata L., Harmonia axyridis (Pallas), and Hippodamia variegata (Goeze), and their position within the communities of predators in the introduced areas of USA, Canada, and Chile. In Europe, much of the research on exotic ladybirds has been conducted on the undesired impact of H. axyridis. Therefore, we summarize the risk assessment data for this species and review the field research investigating the ecological impact on European aphidophagous predators. According to the BIOCAT database of classical BC programs, 212 ladybird species belonging to 68 genera have been released in about 130 years of BC activity, with 14.6% of introductions having resulted in partial, substantial, or complete control of the target pest. However, because post-release evaluation of establishment and BC success has not always been conducted, this rate could underestimate the successful cases. Among other factors, ladybird establishment and pest suppression mostly depend on (1) intrinsic factors, i.e., high voracity, synchronized predator-prey life cycle, and high dispersal ability, and (2) extrinsic factors, i.e., adaptability to the new environment and landscape composition. This review contributes to improved understanding of ladybirds as exotic BC agents.
- Research Advances on Health Effects of Edible Artemisia Species and Some Sesquiterpene Lactones ConstituentsPublication . Trendafilova, Antoaneta; Moujir, Laila M.; Sousa, Pedro M. C.; Seca, Ana M. L.The genus Artemisia, often known collectively as “wormwood”, has aroused great interest in the scientific community, pharmaceutical and food industries, generating many studies on the most varied aspects of these plants. In this review, the most recent evidence on health effects of edible Artemisia species and some of its constituents are presented and discussed, based on studies published until 2020, available in the Scopus, Web of Sciences and PubMed databases, related to food applications, nutritional and sesquiterpene lactones composition, and their therapeutic effects supported by in vivo and clinical studies. The analysis of more than 300 selected articles highlights the beneficial effect on health and the high clinical relevance of several Artemisia species besides some sesquiterpene lactones constituents and their derivatives. From an integrated perspective, as it includes therapeutic and nutritional properties, without ignoring some adverse effects described in the literature, this review shows the great potential of Artemisia plants and some of their constituents as dietary supplements, functional foods and as the source of new, more efficient, and safe medicines. Despite all the benefits demonstrated, some gaps need to be filled, mainly related to the use of raw Artemisia extracts, such as its standardization and clinical trials on adverse effects and its health care efficacy.
- Crianças diferentes, desafios exigentesPublication . Gil, Ana Cristina Correia, dir.; Fialho, Adolfo Fernando da Fonte, ed.Neste número, a rubrica Ágora partilha alguns resultados da frutuosa relação entre a Universidade dos Açores e o Centro de Desenvolvimento Infanto-Juvenil dos Açores (CDIJA). […]. Em “Agora é hora” retomam-se as atividades, em segurança, a partir de casa. Acompanhando esta tendência, a “Conversa Escrita” adianta algumas ideias para toda a comunidade, em tempos de confinamento.
- Biodiversity Patterns of Macroinvertebrate Assemblages in Natural and Artificial Lentic Waters on an Oceanic IslandPublication . Lamelas-López, Lucas; Borges, Paulo A. V.; Serrano, Laura; Gonçalves, Vitor; Florencio, MargaritaThe Azorean islands have been historically affected by human activities, mainly due to the combined effects of habitat degradation and fragmentation, and the introduction of exotic species. We here aim to analyze the role of environmental characteristics and spatial descriptors in supporting regional biodiversity of macroinvertebrates by considering natural ponds and artificial tanks. After the monthly variation of macroinvertebrate assemblages was assessed in three temporary and two permanent ponds in the Azorean island of Terceira during a complete inundation-desiccation annual cycle, the assemblage differences of 12 ponds (three temporary and nine permanent ponds) and 8 closely-located artificial tanks were analyzed across a range of landscape disturbances. Macroinvertebrate assemblages were found to differ according to hydroperiod and sampled months. Although the former explained the highest variance, macroinvertebrate differentiation by hydroperiod was also dependent on the study month. Our results also revealed a consistent monthly pattern of species replacement. However, the contribution of nestedness to the macroinvertebrate β-diversity was notable when temporary ponds were close to desiccation, probably indicating a deterministic loss of species due to the impoverished water conditions of the ponds facing desiccation. When the macroinvertebrate assemblages were analyzed in relation to physico-chemical variations and spatial descriptors, the artificial tanks were not clearly segregated from the natural ponds, and only differentiated by pH differences. In contrast, those natural ponds exhibiting high concentrations of total phosphorous (likely signs of anthropization) also discriminated the ordination of ponds in a distance-based redundancy analysis, and showed impoverished assemblages in comparison with well-preserved ponds. The macroinvertebrate assemblages of the natural ponds showed a significant spatial pattern, but this spatial influence was not significant when tanks and ponds were considered together. Our results suggest that tanks may act as possible reservoirs of biodiversity during the desiccation period of temporary ponds, but are unable to establish successful populations. These fishless permanent tanks can complement the conservation of a biodiversity that is largely maintained by the pristine high-altitude natural ponds. The establishment of a guideline for conservation management that also considers the artificial tanks is necessary to benefit the local and regional Azorean macroinvertebrate diversity.
- Local environmental variables are key drivers of ant taxonomic and functional beta-diversity in a Mediterranean drylandPublication . Wendt, Clara Frasconi; Ceia-Hasse, Ana; Nunes, Alice; Verble, Robin; Santini, Giacomo; Boieiro, Mário; Branquinho, CristinaThe decomposition of beta-diversity (β-diversity) into its replacement (βrepl) and richness (βrich) components in combination with a taxonomic and functional approach, may help to identify processes driving community composition along environmental gradients. We aimed to understand which abiotic and spatial variables influence ant β-diversity and identify which processes may drive ant β-diversity patterns in Mediterranean drylands by measuring the percentage of variation in ant taxonomic and functional β-diversity explained by local environmental, regional climatic and spatial variables. We found that taxonomic and functional replacement (βrepl) primarily drove patterns in overall β-diversity (βtot). Variation partitioning analysis showed that respectively 16.8%, 12.9% and 21.6% of taxonomic βtot, βrepl and βrich variation were mainly explained by local environmental variables. Local environmental variables were also the main determinants of functional β-diversity, explaining 20.4%, 17.9% and 23.2% of βtot, βrepl and βrich variation, respectively. Findings suggest that niche-based processes drive changes in ant β-diversity, as local environmental variables may act as environmental filters on species and trait composition. While we found that local environmental variables were important predictors of ant β-diversity, further analysis should address the contribution of other mechanisms, e.g. competitive exclusion and resource partitioning, on ant β-diversity.
- Effect of Weed Management on the Parasitoid Community in Mediterranean VineyardsPublication . Möller, Gabriella M.; Keasar, Tamar; Shapira, Idan; Möller, Daniella M.; Ferrante, Marco; Segoli, MichalEnriching agroecosystems with non-crop vegetation is a popular strategy for conservation biocontrol. In vineyards, the effects of specific seeded or planted cover crops on natural enemies are well-studied, whereas conserving spontaneously developing weeds received less attention. We compared parasitoid communities between matched pairs of vineyard plots in northern Israel, differing in weed management practices: “herbicide”, repeated herbicide applications vs. “ground cover”, maintaining resident weeds and trimming them when needed. Using suction sampling, we assessed the parasitoids’ abundance, richness, and composition during three grape-growing seasons. Ground cover plots had greater parasitoid abundances and cumulative species richness than herbicide-treated plots, possibly because of their higher vegetation cover and richness. Dominant parasitoid species varied in their magnitude and direction of response to weed management. Their responses seem to combine tracking of host distributions with attraction to additional vegetation-provided resources. Parasitoid community composition was mildly yet significantly influenced by weed management, while season, year, and habitat (weeds vs. vine) had stronger effects. Vineyard weeds thus support local biocontrol agents and provide additional previously demonstrated benefits (e.g., soil conservation, lower agrochemical exposure) but might also attract some crop pests. When the benefits outweigh this risk, weed conservation seems a promising step towards more sustainable agricultural management.
- Xanthones for melanogenesis inhibition : Molecular docking and QSAR studies to understand their anti-tyrosinase activityPublication . Rosa, Gonçalo P.; Palmeira, A.; Resende, Diana I. S. P.; Almeida, Isabel F.; Kane-Pagès, Aida; Barreto, Maria do Carmo; Sousa, E.; Pinto, Madalena M. M.The human skin is constantly exposed to external factors that affect its integrity, UV radiation being one of the main stress factors. The repeated exposure to this radiation leads to increased production of Reactive Oxygen Species (ROS) which activate a series of processes involved in photoaging. Excessive UV exposure also exacerbates melanin production leading to a variety of pigmentation disorders. Xanthones are reported to exhibit properties that prevent deleterious effects of UV exposure and high levels of ROS in the organism, so in this work a wide library of xanthones with different patterns of substitution was synthesized and tested for their inhibitory activity against the skin enzymes tyrosinase, elastase, collagenase and hyaluronidase, many of which were evaluated for the first time. Most of the compounds were tyrosinase inhibitors, with the best one (xanthone 27) presenting an IC50 of 1.9 µM, which is approximately 6 times lower than the IC50 of the positive control kojic acid. Concerning the other enzymes, only one compound presented IC50 lower than 150 µM in elastase inhibition (xanthone 14 = 91.8 µM) and none in collagenase and hyaluronidase inhibition. A QSAR model for tyrosinase inhibitory activity was built using six molecular descriptors, with a partial negative surface area descriptor and the relative number of oxygen atoms being positively contributing to the tyrosinase inhibitory activity. Docking using AutoDock Vina shows that all the tested compounds have more affinity to mushroom tyrosinase than kojic acid. Docking results implied that the tyrosinase inhibitory mechanisms of xanthonic derivatives are attributed to an allosteric interaction. Taken together, these data suggest that xanthones might be useful scaffolds for the development of new and promising candidates for the treatment of pigmentation-related disorders and for skin whitening cosmetic products.
- A política de reconhecimento e a teoria da justiça de Axel HonnethPublication . Fontes, Paulo VitorinoA partir do conceito de reconhecimento de Axel Honneth, considerado como uma necessidade fundamental do ser-humano, apresenta-se o núcleo de uma teoria da justiça que procura especificar as condições intersubjetivas de autorrealização individual. Pretende-se articular uma conceção normativa da justiça com a análise sociológica das sociedades modernas, através da reconstrução normativa e ao colocar a ênfase na liberdade social, baseada na dimensão intersubjetiva das instituições de reconhecimento. A liberdade social supõe o acesso às instituições de reconhecimento. Apresenta-se uma teoria da justiça que analisa as instituições num sentido amplo, através da reconstrução das práticas e condições de reconhecimento já institucionalizadas.
- Análise multidimensional do arquipélago dos Açores determinante para a consecução dos objetivos da OTANPublication . Carvalho, Pedro Nuno Martins; Andrade, Luís Manuel Vieira deAs ilhas dos Açores, porção de terra Portuguesa emersa num local privilegiado pela sua centralidade no Atlântico, detém de um enorme relevo geoestratégico. Este mesmo, foi um fator muito importante que potenciou o convite formulado a Portugal para aderir a OTAN culminando com a assinatura oficial do tratado apos algum tempo de negociações a 04 de abril de 1949. A altura da sua fundação, criada substancialmente para conter a ameaça soviética, contou com a adesão de 12 Estados Membros. Adaptou-se a fim de conseguir dar uma melhor e flexível resposta no decorrer da Guerra Fria e com o seu final assim como do Pacto de Varsóvia, consequência do desmembramento do bloco comunista Soviético, a aliança perde efetivamente o inimigo físico, razão para a qual foi constituída, conduzindo a um período conturbado quanto a justificação ou pertinência da continuação desta aliança. Analisada a conjuntura da altura e reformuladas as suas tarefas e responsabilidades, a OTAN sofreu uma reforma estrutural. Não deixou de lado o principal objetivo de garantir a defesa mutua dos seus Estados Membros, mas focou-se também na gestão de crises e nas operações de apoio a paz. A par da evolução tecnológica, fenómenos como a globalização, intrinsecamente associados a imprevisibilidade de ameaças e novos desafios, a OTAN continua em dinâmica evolução, verificando-se uma deslocação do foco de poder do Atlântico para o Medio Oriente. No entanto, os Açores nunca foram descartados quanto ao seu valor no que concerne a consecução dos objetivos definidos pela organização.