Universidade do Algarve
Recent publications
Ocean acidification (OA) has been identified as one of the major climate-change related threats, mainly due to its significant impacts on marine calcifiers. Among those are the calcareous green algae of the genus Halimeda that are known to be major carbonate producers in shallow tropical and subtropical seas. Hence, any negative OA impacts on these organisms may translate into significant declines in regional and global carbonate production. In this study, we compiled the available information regarding Halimeda spp. responses to OA (experimental, in situ), with special focus on the calcification responses, one of the most studied response parameters in this group. Furthermore, among the compiled studies (n = 31), we selected those reporting quantitative data of OA effects on algal net calcification in an attempt to identify potential general patterns of species- and/or regional-specific OA responses and hence, impacts on carbonate production. While obtaining general patterns was largely hampered by the often scarce number of studies on individual species and/or regions, the currently available information indicates species-specific susceptibility to OA, seemingly unrelated to evolutionary lineages (and associated differences in morphology), that is often accompanied by differences in a species’ response across different regions. Thus, for projections of future declines in Halimeda-associated carbonate production, we used available regional reports of species-specific carbonate production in conjunction with experimental OA responses for the respective species and regions. Based on the available information, declines can be expected worldwide, though some regions harbouring more sensitive species might be more impacted than others.
The Portuguese lower classes were the bearers of a very rich oral literature, made of folktales, legends, folk beliefs, etcetera, which began to be collected in the late nineteenth century, and is still present nowadays in people’s memories. The latest material has been collected since 1994 by students from the University of the Algarve through folkloristic fieldwork, recording the texts digitally or on audio tape. Stories and beliefs relating to werewolves form part of a complex puzzle, which by nature is fragmentary, subjective, and full of gaps. The name of the supernatural creature, lobisomem (litt. wolfman), is common to the entire Portuguese territory despite the phonetic diversity and many local dialects. Nevertheless, the Portuguese werewolf is seldom a wolf; as a rule, it is a horse in the northern half of the country and a donkey or dog in the southern half, and could also be a pig, a goat, or another animal. The concept of the werewolf serves to magnify the perception of the Other, the stranger, the outlaw, and the deviant in traditional conservative societies. Its purpose is to separate the normal from the abnormal, and the natural from the supernatural, serving also as a provider of cautionary tales for the common people, particularly young people. It is not by chance that many people, when questioned, said that they heard those stories from old people when they were children. The transmission of those belief narratives was made principally within the little community of neighbours, friends and relatives. The main characters of the stories are, in general, known people belonging to the community. The stories have, then, a practical function of meddling in people’s daily lives, and I argue that this exists in order to exact social control upon deviance. The process is symbolical enough to keep a potential touchy, or even dangerous, situation hidden. Shameful situations inside the family, like vagrancy, sexual deviance or domestic violence, are serious events in a traditional society and touchy enough to not be handled directly, at the cost of fracturing the community. To be a witch or a werewolf, or to have the devil inside the body, are metaphors used to deal symbolically with deviant behavior in those societies, especially if the stories have the capacity to identify the problem and provide the right solution for it. Sometimes the werewolf is the scapegoat of the community, sometimes its guardian angel, and sometimes a poor fellow abandoned by chance. As a part of the legend genre, werewolves are normally linked to reality by a specific cultural bias, in this case the Portuguese rural culture.
Skeletal disorders are problematic aspects for the aquaculture industry as skeletal deformities, which affect most species of farmed fish, increase production costs and affect fish welfare. Following recent findings that show the presence of osteoactive compounds in marine organisms, we evaluated the osteogenic and mineralogenic potential of commercially available microalgae strains Skeletonema costatum and Tetraselmis striata CTP4 in several fish systems. Ethanolic extracts increased extracellular matrix mineralization in gilthead seabream (Sparus aurata) bone-derived cell cultures and promoted osteoblastic differentiation in zebrafish (Danio rerio) larvae. Long-term dietary exposure to both extracts increased bone mineralization in zebrafish and upregulated the expression of genes involved in bone formation (sp7, col1a1a, oc1, and oc2), bone remodeling (acp5a), and antioxidant defenses (cat, sod1). Extracts also improved the skeletal status of zebrafish juveniles by reducing the incidence of skeletal anomalies. Our results indicate that both strains of microalgae contain osteogenic and mineralogenic compounds, and that ethanolic extracts have the potential for an application in the aquaculture sector as dietary supplements to support fish bone health. Future studies should also identify osteoactive compounds and establish whether they can be used in human health to broaden the therapeutic options for bone erosive disorders such as osteoporosis.
In today's hyper-connected world, digital games and online gaming communities occupy a prominent place in the communication system, in social media, forums or Internet communities, where online hate speech (OHS) takes place, frequently and publicly, triggering toxic environments. In this chapter we present a case study based on interviews, distributed in two sessions, to ten participants with 12 and 13 years old, and an experience over the SG In[The Hate Booth], as a counterproposal to address OHS. The qualitative data approaches three aspects: the experiences with OHS, the perspectives about OHS and the possible solutions to counteract OHS. We conclude that OHS is a common complaint from players and a characteristic behavior in game communities. Data shows that even users who don’t identify themselves with this behavior accept it as part of online environments and agree that this toxicity continues outside the in-game screen with effects in everyday life. The pedagogical approach, namely through SG, is perceived as a possible measure to counteract the OHS.
This study analyzes the written word and typography in a modern and postmodern context, regarding its view and usage in audiovisual and digital systems. Analyzing different periods, works and artists, we aim to understand the potential of typography in the contemporary artistic discourse, mainly exploring the visual, dynamic and interactive components of typography. The theoretical study explored here serves as the basis for a project that foresees the production of a video installation, constructed from the documental and textual collection of Fernando Gonçalves Lavrador. The objective is to disseminate this collection through one exhibition, where a selection of his texts will be appropriated and transformed into artifacts that will converge textual, imagetic and animated elements. Until this public presentation, which is expected to happen in 2024, a process of experimentation with different styles, techniques and materials is being prepared. The results obtained so far—four short films and an interactive program—will also be presented in this paper. The preparatory act that precedes the appropriation of Lavrador's heritage aims to improve the artistic processes around the themes explored in this paper and study new possibilities of using typography as an artistic component in a computational and videographic system.
According to career literature, greater parental support seems to be associated with higher levels of career exploration. This relationship may be mediated by self-regulatory processes, such as social-emotional skills, as curiosity. However, despite the large number of empirical studies that analyze the antecedents of career exploration, there are no references, to our knowledge, to the role of socio-emotional skills. Following this gap, the present study aims to examine the extent to which perceived parental support is associated with career exploration through the mediating effect of curiosity (socio-emotional skill), among a group of 8th and 9th grade students from public schools in southern Portugal (N = 540). An integrated model was conducted using AMOS 20.0 and the results revealed that curiosity is a partial mediator of the relationship between perceived parental support and career exploration. These results highlight the importance of considering socio-emotional skills (such as curiosity) when designing interventions to foster adaptive career behaviors. Theoretical and practical implications are discussed to open the opportunity to progressively extend the participation of proximal contexts (e.g., families) to career and socio-emotional skills development processes.
This work aimed to optimize and characterize the biomass production of Pavlova gyrans through a sequential multivariate approach. Among seventeen cultivation parameters, light intensity, NaNO3, and CuSO4·5H2O were identified as the most significative factors (p < 0.10) for biomass productivity. Together with NaH2PO4·H2O, these variables were further studied in order to maximize the biomass production of P. gyrans, with the optimum growth conditions identified as 700 μmolphotons m⁻² s⁻¹ light intensity, 1500 mg L⁻¹ NaNO3, 6 μg L⁻¹ CuSO4·5H2O and 40 mg L⁻¹ NaH2PO4·H2O. These conditions allowed a 3.8-fold increase in biomass production (2.26 g AFDW per L) and improved the biochemical profile (p < 0.05) when compared with the control (Walne's medium). Namely, it was increased the contents of protein (from 10.59 to 30.76% DW), PUFAs (from 37.13 to 47.11% TFA), n − 3 FAs (26.49 to 38.27% TFA), and DHA (from 5.73 to 10.33% TFA). The nutritional value of the microalga (p < 0.05) was also improved, decreasing its atherogenic (AI – from 1.34 to 0.93) and thrombogenic (TI – from 0.45 to 0.24) indices, while the hypocholesterolemic index (HI) increased from 0.96 to 1.63. This work highlights the importance of different growth conditions in P. gyrans, playing a relevant role in the large-scale implementation of this microalga with beneficial nutritional composition for human consumption.
Process‐based morphodynamic models can be useful in understanding coastal dune responses to disturbances, as well as possible evolutionary patterns. To this aim, we employ Duna, a simplified 1D morphodynamic model, to assess the influence of dune morphology (height and slope) on sand transfer and deposition across the dune profile for different beach widths and wind incidence angles through idealized experiments. Simulations of real conditions show good model performance, both in wind flow reproduction and in topographic change along the dune profiles tested. The idealized experiments show that wind speed increases and sand accumulation decreases logarithmically with dune height and linearly with stoss slope along the dune profile. Fetch and cosine transport limiting parameters are reflected in the sand accumulated windwards from the toe, while sand transfer to the dune appears controlled by multiple factors; the higher the dune and/or the narrower the beach, the likelier that maximum accumulation occurs under oblique winds. Results point to two different types of evolution for high dunes. Either the vegetation is dense enough to maintain the stoss position, in which case vertical growth near‐ceases and seaward progradation is promoted, or the stoss is eroded and landward retreat dominates, in which case sand transfer to the crest and lee continues as a mixture of low input from the beach and recycled sand from the stoss.
This paper presents a systematic review update regarding mindfulness theories applied to tourism, complemented with a bibliometric analysis. Scientific studies listed in the WOS, SCOPUS, PubMed and PsycInfo databases were analysed using PRISMA guidelines. Twenty-five studies were selected for review from 670 records identified. In recent years, mindfulness has proved to be a promising area of research in tourism, and the number of published studies is increasing. The findings reveal a positive association between mindful-ness and tourism experiences, suggesting that tourists who adopt states of mindfulness during their travels benefit from increased pro-environmental behaviours, satisfaction levels, and memorable experiences, leading to destination loyalty. This study provides an in-depth overview of the literature, and helps redress the lack of bibliometric studies in this field. It also identifies common areas of current research interest, offers insights into commonly studied themes, and seeks to raise awareness about the relevance of the concept of mind-fulness in tourist experiences and well-being by suggesting implications for research and tourism management.
We present three new coset manifolds named Dixon-Rosenfeld lines that are similar to Rosenfeld projective lines except over the Dixon algebra $$\mathbb {C}\otimes \mathbb {H}\otimes \mathbb {O}$$ C ⊗ H ⊗ O . Three different Lie groups are found as isometry groups of these coset manifolds using Tits’ formula. We demonstrate how Standard Model interactions with the Dixon algebra in recent work from Furey and Hughes can be uplifted to tensor products of division algebras and Jordan algebras for a single generation of fermions. The Freudenthal–Tits construction clarifies how the three Dixon-Rosenfeld projective lines are contained within $$\mathbb {C}\otimes \mathbb {H}\otimes J_{2}(\mathbb {O})$$ C ⊗ H ⊗ J 2 ( O ) , $$\mathbb {O}\otimes J_{2}(\mathbb {C}\otimes \mathbb {H})$$ O ⊗ J 2 ( C ⊗ H ) , and $$\mathbb {C}\otimes \mathbb {O}\otimes J_{2}(\mathbb {H})$$ C ⊗ O ⊗ J 2 ( H ) .
Pancreatic cancer represents one of the most lethal cancer types worldwide, with a 5-year survival rate of less than 5%. Due to the inability to diagnose it promptly and the lack of efficacy of existing treatments, research and development of innovative therapies and new diagnostics are crucial to increase the survival rate and decrease mortality. Nanomedicine has been gaining importance as an innovative approach for drug delivery and diagnosis, opening new horizons through the implementation of smart nanocarrier systems, which can deliver drugs to the specific tissue or organ at an optimal concentration, enhancing treatment efficacy and reducing systemic toxicity. Varied materials such as lipids, polymers, and inorganic materials have been used to obtain nanoparticles and develop innovative drug delivery systems for pancreatic cancer treatment. In this review, it is discussed the main scientific advances in pancreatic cancer treatment by nano-based drug delivery systems. The advantages and disadvantages of such delivery systems in pancreatic cancer treatment are also addressed. More importantly, the different types of nanocarriers and therapeutic strategies developed so far are scrutinized.
Wood artefacts rarely survive from the Early Stone Age since they require exceptional conditions for preservation; consequently, we have limited information about when and how hominins used this basic raw material¹. We report here on the earliest evidence for structural use of wood in the archaeological record. Waterlogged deposits at the archaeological site of Kalambo Falls, Zambia, dated by luminescence to at least 476 ± 23 kyr ago (ka), preserved two interlocking logs joined transversely by an intentionally cut notch. This construction has no known parallels in the African or Eurasian Palaeolithic. The earliest known wood artefact is a fragment of polished plank from the Acheulean site of Gesher Benot Ya’aqov, Israel, more than 780 ka (refs. 2,3). Wooden tools for foraging and hunting appear 400 ka in Europe4–8, China⁹ and possibly Africa¹⁰. At Kalambo we also recovered four wood tools from 390 ka to 324 ka, including a wedge, digging stick, cut log and notched branch. The finds show an unexpected early diversity of forms and the capacity to shape tree trunks into large combined structures. These new data not only extend the age range of woodworking in Africa but expand our understanding of the technical cognition of early hominins¹¹, forcing re-examination of the use of trees in the history of technology12,13.
This work investigates the potential of 70% ethanolic leaf extracts of Rubus idaeus L., Cistus ladanifer L. and Erica andevalensis in the metal separation from synthetic unimetallic solutions of different metals and a leachate obtained from the leaching of PCBs. Results from the experiments with unimetallic solutions revealed R. idaeus and E. andevalensis extracts induced separation of more than 95% of the initial Au(III), while C. ladanifer separated ~78% of this metal. Thereafter, application of three plant extracts to real Au bearing leachate obtained from PCBs leaching, revealed about 96, 95 and 90% Au recovery with R. idaeus, C. ladanifer and E. andevalensis extracts, respectively with 15–60% co-removal of Pb and less than 15% of other metals. The reduction of Au(III) ions into Au(0) nanoparticles by R. idaeus extract was confirmed by molecular UV–Visible, and FT-IR analysis showed the involvement of plant secondary metabolites in Au bio-reduction and bio-stabilization. Particles obtained from the application of R. idaeus extract to the leachate were initially analyzed with XRD and results confirmed the presence of Au(0) with contamination of PbSO4, which was completely removed by washing with 1 M HCl. Thereafter, results from STEM-EDS analysis showed the presence of Au particles conjugated with organic material and other metals. Consequently, particles were subjected to another washing step with acetone. Afterwards, STEM-EDS showed pure Au microparticle clusters (~0.8 μm) with flower-shaped or apparently cubic morphologies, and HRSTEM showed the tiny nanoparticles (~20 nm), which form the clusters. Graphical Abstract
Marine heatwaves (MHWs) are becoming increasingly common, with devastating ecosystem impacts. However, MHW understanding has almost exclusively relied on sea surface temperature with limited knowledge about their subsurface characteristics. Here we estimate global MHWs from the surface to 2,000 m depth, covering the period 1993–2019, and explore biodiversity exposure to their effects. We find that MHWs are typically more intense in the subsurface at 50–200 m and their duration increases up to twofold with depth, although with large spatial variability linked to different oceanographic conditions. Cumulative intensity (a thermal stress proxy) was highest in the upper 250 m, exposing subsurface biodiversity to MHW effects. This can be particularly concerning for up to 22% of the ocean, where high cumulative intensity overlapped the warm range edge of species distributions, thus being more sensitive to thermal stress. Subsurface MHWs can hence drive biodiversity patterns, with consequent effects on ecological interactions and ecosystem processes.
This article evaluates how solar radiation influences the thermal comfort of the occupants of an auditorium with circular geometry under winter conditions. The auditorium is divided into four amphitheatres of equal dimensions and glazed surfaces of equal dimensions are mounted throughout its outer envelope. The occupants’ thermal comfort is assessed by the Predicted Mean Vote index (PMV). The building thermal software used is based on two numerical models, the Circular Auditorium Geometry and the Circular Auditorium Thermal Modelling. The Circular Auditorium Geometry is based on geometric cylindrical coordinates. The Circular Auditorium Thermal Modelling evaluates, in a transient regime, the thermal response of the auditorium and thermal comfort provided to its occupants. Compartment ventilation is provided by mechanically ventilated outdoor air at an air renewal rate directly linked to the number of occupants. The incoming solar radiation in the two amphitheatres with the glazed surfaces facing north is low, while in the two amphitheatres with the glazed surfaces facing south, it is too high. Consequently, in general, the occupants’ thermal comfort level is unacceptable in north-facing amphitheatres for being too cold and in south-facing amphitheatres for being too hot. So, to ensure that the thermal comfort level of the occupants is acceptable, a strategy was implemented that consisted of adapting ventilation and the level of clothing during occupancy.
The simulation of the acoustic and thermal environment in office spaces is developed and applied in this study. A virtual thermal and binaural simulator is considered. The habitants’ thermal and clothing numerical systems are evaluated in the virtual thermal simulator. The direct sound component and the indirect sound component are evaluated, and the reverberation time (RT) is calculated by the virtual binaural simulator. This study is conducted in an office equipped with a system of ventilation with horizontal confluent jets methodology and occupied by two habitants. The space RT and the environmental variables surrounding to the simulator and in the office space are evaluated.
Iron is an essential micronutrient for citrus, playing an important role in photosynthesis and yield. The aim of this paper was to evaluate the tolerance to Fe deficiency of five citrus rootstocks: sour orange (S), Carrizo citrange (C), Citrus macrophylla (M), Troyer citrange (T), and Volkamer lemon (V). Plants were grown for 5 weeks in nutrient solution that contained the following Fe concentrations (in µM): 0, 5, 10, 15, and 20. At the end of the experiment, biomass (dry weight-DW), leaf area, total leaf chlorophyll (CHL), and the activity of root chelate reductase (FCR) were recorded. Additionally, the mineral composition of roots (R) and shoots (S) was evaluated. Principal component analysis was used to study the relationships between all parameters and, subsequently, the relations between rootstocks. In the first component, N-S, P-S, Ca-S, Cu-S, Zn-S, Mn-S, Zn-R, and Mn-R concentrations were related to leaf CHL and FCR. Increases in leaf CHL, Mg-R, and DW (shoots and roots) were inversely related to Cu-R, which was shown in the second component. The values obtained were consistent for V10, C15, and C20, but in contrast for S0 and S5. In conclusion, micronutrient homeostasis in roots and shoots of all rootstocks were affected by Fe stress conditions. The Fe/Cu ratio was significantly related to CHL, which may be used to assist rootstock performance.
A comprehensive approach is presented to analyse season's coastal upwelling represented by weekly sea surface temperature (SST) image grids. Our three‐stage data recovery clustering method assumes that the season's upwelling can be divided into shorter periods of stability, ranges, each to be represented by a constant core and variable shell parts. Corresponding clustering algorithms parameters are automatically derived by using the least‐squares clustering criterion. The approach has been successfully applied to real‐world SST data covering two distinct regions: Portuguese coast and Morocco coast, for 16 years each.
Pitaya is one of the fruit species whose demand has increased in recent years due to the numerous health benefits and lucrative price of the fruit and its by-products. In Europe, the Iberian Peninsula and other Mediterranean countries are the ones with favorable climatic conditions for its cultivation. This document describes much of the history of pitaya in the Iberian Peninsula and the difficulties related to its cultivation. A bibliographical survey was carried out on the culture of pitaya in the world, focusing on the edaphoclimatic requirements, and on the possibility of this becoming a consolidated crop in the Iberian Peninsula. The relatively low water requirement of pitaya makes this crop sustainable among crops that require irrigation. In addition, we provide a perspective for use and research of this emerging crop. There has been an exponential growth of scientific publications on pitaya in the last decade; however, much more needs to be researched to know how to increase productivity as well as the sensory quality of fruits in different regions. This sustainable crop is a good option to diversify fruit production in the Iberian Peninsula.
Grand Lebesgue spaces, well-known on sets of finite measure, are studied on general measure spaces \((X,\mu )\) with admission of \(\mu (X)=\infty\). In this case, the grand space is defined via the so-called grandizer. It is shown that the classical Lebesgue space is embedded into the grand Lebesgue space if and only if the grandizer is in \(L^1(X)\). Embedding between grand Lebesgue spaces with different grandizers is also considered. The main results concern the boundedness of maximal, singular, and fractional operators in grand Lebesgue spaces over quasi-metric measure spaces \((X,d, \mu )\). Application to such operators over \(\mathbb S^{n-1}\) and homogeneous groups on \(\mathbb {R}^n\) is also given.
Institution pages aggregate content on ResearchGate related to an institution. The members listed on this page have self-identified as being affiliated with this institution. Publications listed on this page were identified by our algorithms as relating to this institution. This page was not created or approved by the institution. If you represent an institution and have questions about these pages or wish to report inaccurate content, you can contact us here.
3,781 members
Alice Newton
  • Faculty of Sciences and Technology
Jose Leitao
  • Departamento de Ciências Biológicas e Bioengenharia
Americo Lemos
  • Departamento de Química e Farmácia
Ester A Serrao
  • Centro de Ciências do Mar (CCMAR)
Ana Paula Fontes
  • Escola Superior de Saúde (ESS)
CIQA, FCT Ed2 Universidade do Algarve, Campus de Gambelas, 8005-139, Faro, Portugal
Head of institution
José Moreira
+351 289 800 900
+351 289 800 066