Avaliação dos efeitos ecológicos de filtros ultravioleta em ecosistemas lóticos portugueses

Organic UV-filters are chemicals present in several personal care products and on other materials (plastics, paints, etc) to protect against ultraviolet radiation. The use of these compounds has been increasing throughout the years and, consequently, they are now considered global emergent contaminants of the aquatic environment. In fact, UV-filters have been frequently found in river and lake waters but to date, only scarce information exists about their effects and it is mostly based in acute or chronic toxicity data for a limited number of species. Due to their physico-chemical properties, UV- filters accumulate in biota and sediments and are expected to co-occur together with other persistent contaminants. Moreover, and despite uncertainties about their specific mode of action, research has shown endocrine disruption caused by exposure to organic UV-filters in several species. Investigation on the ecological effects of organic UV-filters is urgent for a correct environmental risk assessment. For that, studies should be focused on ecotoxicological data from benthic organisms considering relevant endpoints and exposure scenarios including binary mixtures. This will allow to address potential long-term as well as community and ecosystem level effects of organic UV-filters. Thus, the purpose of this thesis was to evaluate the effects of UV-filters using an integrated approach combining sub-organismal, organismal, population and community level responses, aiming to produce comprehensive and sound ecotoxicological data for freshwaters. With that purpose four specific objectives were proposed: i) assess the effects of selected UV-filters (Benzophenone-3 (BP3); 3-(4-methylbenzylidene)camphor (4-MBC) and Octocrylene (OC)) on two aquatic species, the dipteran Chironomus riparius (a model organism widely used in ecotoxicological assays) and the trichopteran Sericostoma vittatum (an endemic species of Iberian peninsula), both aquatic detritivores with an important role in the streams and rivers; ii) assess the effects of binary mixtures of different UV-filters and UV- filters combined with an insect repellent, DEET (N,N-diethyl-3-methylbenzamide) in C. riparius reproductive traits ; iii) assess the long-term effects of BP3 exposure over two consecutive C. riparius generations and iv) assess the effects of 4-MBC in the structure of macroinvertebrates community and functioning of ecosystem using a mesocosms approach. Obtained results showed that selected UV-filters indeed caused deleterious effects on both insect species at environmental relevant concentrations with reductions in the growth, feeding and development rates. At the sub-organismal level, C. riparius and S. vittatum showed different patterns of response to UV-filters exposure and, despite evidences of metabolic costs related with detoxification, no evidences of oxidative stress or neurotoxicity were found. Additionally, results obtained in mixture exposures showed synergistic interactions for some C. riparius reproduction related traits for binary mixture of BP3 and 4-MBC as well as for mixture containing BP3 and DEET. These suggest that individual chemical testing can underestimate toxicity of organic UV-filters under natural conditions. Concerning C. riparius long-term multigenerational exposure to BP3, our results showed that C. riparius fertility is strongly reduced by BP3 exposure being the filial (F1) generation more sensitive than the parental (P) generation. Moreover, the F1 generation exposed under control conditions but whose parents were exposed to BP3 showed to be affected. All these results indicate carry-over effects, pointing out to possible epigenetic/transgenerational effects. Finally, community ecotoxicological experiments using artificial streams (mesocosms) showed no effects of 4-MBC on the structure of macroinvertebrate community nor on leaf litter decomposition. However, primary production was strongly reduced due to 4-MBC exposure. These results, although not in agreement with the previous laboratory assays performed with detritivore species, suggest potential bottom up indirect effects caused by the presence of organic UV-filters in sediments. In conclusion, the results obtained in this work suggest that UV-filters present risk to freshwater benthic invertebrate communities and reinforce the need of using complex and higher tier ecotoxicity studies to a better environmental risk assessment of these emergent contaminants.Os Filtros ultravioleta (filtros UV) são compostos químicos usados em vários produtos de higiene pessoal e materiais (plásticos, tintas, etc.) de modo a proteger contra danos causados pela radiação ultravioleta. O uso destes compostos tem vindo a aumentar nos últimos anos sendo já considerados contaminantes emergentes dos ecossistemas aquáticos. De facto, estes compostos têm vindo a ser detetados em lagos e rios, mas até à data pouca informação existe sobre os seus efeitos nos ecossistemas aquáticos, sendo que os estudos existentes se centram em ensaios laboratoriais e num reduzido número de espécies. Contudo, devido às suas propriedades físico-químicas é esperado que os filtros UV acumulem nos sedimentos e nos organismos e coocorram com outros contaminantes. No entanto, embora o modo de ação dos filtros UV não seja totalmente conhecido, estudos prévios têm mostrado disrupção endócrina causada pela exposição a estes contaminantes em organismos aquáticos. Posto isto, uma avaliação dos efeitos ecotoxicológicos dos filtros UV é urgente para uma correta avaliação do risco ambiental. Assim, os estudos ecotoxicológicos devem-se focar em organismos bentónicos considerando parâmetros e cenários de exposição relevantes, o que nos permitirá determinar potenciais efeitos a longo prazo assim como efeitos ao nível das comunidades dos ecossistemas. Este trabalho propôs avaliar e perceber quais os efeitos dos filtros UV em organismos e comunidades de água doce usando uma abordagem baseada em diferentes níveis de organização biológica e tendo como intuito gerar dados ecotoxicológicos robustos e mais abrangentes. Para tal, foram estabelecidos vários objetivos específicos: 1) avaliar os efeitos de diferentes filtros UV (Benzofenona-3 (BP3); 3-(4-methylbenzylidene)camphor (4-MBC) e Octocrileno (OC)) usando duas espécies de invertebrados aquáticos detritívoros, o díptero Chironomus riparius (uma espécie modelo amplamente utilizada em ensaios ecotoxicológicos) e o tricóptero Sericostoma vittatum (uma espécie endémica da Península Ibérica), ambos com grande importância nos ecossistemas lóticos portugueses; 2) avaliar os efeitos de misturas de diferentes filtros UV, e de filtros UV juntamente com um repelente de insetos (N,N-diethyl-3-methylbenzamide -DEET) em parâmetros relacionados com a reprodução de C. riparius; 3) avaliar os efeitos multigeracionais decorrentes de exposição a BP3 em C. riparius; 4) usando sistemas de rios artificiais avaliar os efeitos do 4-MBC na estrutura e funcionamento dos ecossistemas. Os resultados obtidos mostraram que, de facto, os filtros UV selecionados causaram efeitos tóxicos em ambas as espécies usadas a concentrações ambientalmente relevantes, observando-se reduções ao nível do crescimento e das taxas alimentares assim como atrasos no desenvolvimento. Ao nível subcelular C. riparius e S. vittatum mostraram diferentes padrões de resposta à exposição aos filtros UV e apesar de se observarem custos metabólicos relacionados com os processos de destoxificação, não se observaram efeitos em termos de stress oxidativo nem neurotoxicidade. Adicionalmente, os resultados obtidos na exposição às misturas entre químicos revelaram interações sinergísticas para alguns parâmetros reprodutivos de C. riparius para as ambas as misturas testadas (BP3 – 4-MBC; BP3 - DEET). Estes resultados sugerem que exposições individuais aos filtros UV podem subestimar a toxicidade destes contaminantes em condições naturais. Nos ensaios multigeracionais observou-se também uma forte redução na fertilidade de C. riparius expostos a BP3. Observou-se ainda que a segunda geração foi mais afetada que a geração parental mesmo se mantida em condições controlo, mas cujos pais tinham sido previamente expostos a BP3. Todos estes resultados indicam que a BP3 provoca efeitos latentes na geração parental que são posteriormente observados nos descendentes, apontando assim para efeitos epigenéticos/transgeracionais. Por último, nos ensaios dos mesocosmos, não foram observados efeitos do 4-MBC na estrutura das comunidades de macroinvertebrados nem na degradação da matéria orgânica, em contraste com o forte efeito observado na produção primária. Estes resultados, embora não concordando com os resultados obtidos em ensaios laboratoriais sugerem potenciais efeitos indiretos da presença dos filtros UV nos sedimentos. Em conclusão, os resultados obtidos nesta tese indicam que os filtros UV apresentam risco para os organismos bentónicos e reforçam a necessidade de utilizar abordagens integradas com maior relevância ecológica para uma melhor avaliação do risco ambiental destes contaminantes emergentes.Programa Doutoral em Biologi

Efeitos do cádmio em cadeias tróficas de processamento de detritos

Mestrado em Biologia Aplicada - Microbiologia Clínica e AmbientalA integridade ecológica dos ecossistemas é na maior parte das vezes avaliada em termos de ocorrência de espécies e composição das comunidades e não em termos de relações tróficas entre espécies ou parâmetros funcionais. O processamento de detritos é um processo ecológico vital para os ecossistemas lóticos, mediado por microrganismos e invertebrados aquáticos. Nestas cadeias tróficas, os invertebrados fragmentadores contribuem para a ciclo de nutrientes através da transformação de matéria orgânica particulada grosseira em matéria orgânica particulada fina que serve de alimento para os invertebrados coletores. O nosso objetivo passou por avaliar os efeitos combinados do cádmio e da alteração na qualidade dos recursos (espécie de folha) na cadeia trófica de detritos e na interação entre fragmentadores – coletores. Em laboratório folhas de amieiro (espécie nativa) e de eucalipto (espécie exótica) foram condicionadas em diferentes concentrações de cádmio (0, 50 e 200 μg/L). A comunidade microbiana presente nas folhas provenientes de diferentes tratamentos foi analisada através da técnica molecular DGGE e a taxa de respiração microbiana foi medida. Sericostoma vittatum (tricóptero fragmentador) e Chironomus riparius (um díptero coletor) foram expostos às mesmas concentrações de cádmio e alimentados com discos de folhas correspondentes. Foram avaliados, em microcosmos, o crescimento de C. riparius e a perda de peso das folhas. O cádmio afetou o condicionamento das folhas e provocou alterações na diversidade de fungos em ambas as espécies de folhas. A comunidade microbiana presente no amieiro e no eucalipto mostrou reagir de maneira diferente ao cádmio. Este apenas afetou a decomposição das folhas de amieiro através da redução da alimentação dos invertebrados e também afetou o crescimento larvar de C. riparius. Esta espécie mostrou não ser exclusivamente coletora sendo capaz de se alimentar de folhas de amieiro na ausência de invertebrados fragmentadores. Contudo os fragmentadores mostraram promover o crescimento dos coletores no tratamento com eucalipto como fonte de alimentação. Estes resultados levam-nos a crer que a hipótese de facilitação entre fragmentadores - coletores pode ser tida como verdadeira mas que depende da qualidade dos recursos bem como das espécies de detritívoros presentes. Os resultados sugerem ainda que as cadeias de processamento de detritos podem ser ferramentas valiosas em ecotoxicologia de comunidades. Mais estudos com a utilização de diferentes espécies de detritívoros e de outros stressores (naturais e antropogénicos) deverão continuar para melhor avaliar possíveis efeitos indiretos de contaminantes ao longo destas cadeias de processamento de detritos sob diferentes cenários ecológicos.The ecological integrity of ecosystems is often evaluated in terms of species occurrence and composition of communities and not in terms of trophic relationships between species or functional parameters. The processing of detritus is a vital ecological process for freshwater ecosystems, mediated by microorganisms and aquatic invertebrates. Here, shredders contribute to the nutrient cycle, transforming coarse into fine particulate organic matter which serve as food for collectors. The aim of this work was to evaluate the combined effects of cadmium exposure and changes in resource quality (leaf species) on detritus trophic chain and on shredder–collector interactions. In the laboratory, alder leaves (native species) and eucalyptus (exotic species) were conditioned at different cadmium concentrations (0, 50 and 200 μg/L). The microbial community present in leaves from the different treatments was analyzed by molecular DGGE technique and microbial respiration rates were measured. Sericostoma vittatum (a caddisfly shredder) and Chironomus riparius (a midge collector) were exposed to the same concentrations of cadmium and fed the corresponding leaf discs. C. riparius growth and leaf weight loss were evaluated in these multispecies microcosms. Cadmium exposure affected the leaf conditioning and the reduction in fungal diversity in both leaf species was clear. Cadmium affected the decomposition of alder leaves through reductions in invertebrate feeding and also impaired C. riparius’ growth. C. riparius showed to be a non-exclusive collector and capable of feeding on alder leaf discs in the absence of shredders. However shredders appear to promote collectors growth in treatments with eucalyptus as food source.. The observed pattern suggest that shredder-collector facilitation hypothesis can hold true and also that it might be dependent on resource quality and detritivore species present. The results suggest that detritus processing chains can be valuable tools to community ecotoxicology. We advocate that these investigations should continue with the use of different detritivore species and stressors (natural and anthropogenic) to improve our current understanding of indirect effects of contaminants in detritus based food webs under different ecological scenarios

Global disparities in surgeons’ workloads, academic engagement and rest periods: the on-calL shIft fOr geNEral SurgeonS (LIONESS) study

: The workload of general surgeons is multifaceted, encompassing not only surgical procedures but also a myriad of other responsibilities. From April to May 2023, we conducted a CHERRIES-compliant internet-based survey analyzing clinical practice, academic engagement, and post-on-call rest. The questionnaire featured six sections with 35 questions. Statistical analysis used Chi-square tests, ANOVA, and logistic regression (SPSS® v. 28). The survey received a total of 1.046 responses (65.4%). Over 78.0% of responders came from Europe, 65.1% came from a general surgery unit; 92.8% of European and 87.5% of North American respondents were involved in research, compared to 71.7% in Africa. Europe led in publishing research studies (6.6 ± 8.6 yearly). Teaching involvement was high in North America (100%) and Africa (91.7%). Surgeons reported an average of 6.7 ± 4.9 on-call shifts per month, with European and North American surgeons experiencing 6.5 ± 4.9 and 7.8 ± 4.1 on-calls monthly, respectively. African surgeons had the highest on-call frequency (8.7 ± 6.1). Post-on-call, only 35.1% of respondents received a day off. Europeans were most likely (40%) to have a day off, while African surgeons were least likely (6.7%). On the adjusted multivariable analysis HDI (Human Development Index) (aOR 1.993) hospital capacity > 400 beds (aOR 2.423), working in a specialty surgery unit (aOR 2.087), and making the on-call in-house (aOR 5.446), significantly predicted the likelihood of having a day off after an on-call shift. Our study revealed critical insights into the disparities in workload, access to research, and professional opportunities for surgeons across different continents, underscored by the HDI

Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19

Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe

Nrf2-interacting nutrients and COVID-19 : time for research to develop adaptation strategies

There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPAR gamma:Peroxisome proliferator-activated receptor, NF kappa B: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2 alpha:Elongation initiation factor 2 alpha). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT(1)R axis (AT(1)R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity

Catálogo Taxonômico da Fauna do Brasil: setting the baseline knowledge on the animal diversity in Brazil

The limited temporal completeness and taxonomic accuracy of species lists, made available in a traditional manner in scientific publications, has always represented a problem. These lists are invariably limited to a few taxonomic groups and do not represent up-to-date knowledge of all species and classifications. In this context, the Brazilian megadiverse fauna is no exception, and the Catálogo Taxonômico da Fauna do Brasil (CTFB) (http://fauna.jbrj.gov.br/), made public in 2015, represents a database on biodiversity anchored on a list of valid and expertly recognized scientific names of animals in Brazil. The CTFB is updated in near real time by a team of more than 800 specialists. By January 1, 2024, the CTFB compiled 133,691 nominal species, with 125,138 that were considered valid. Most of the valid species were arthropods (82.3%, with more than 102,000 species) and chordates (7.69%, with over 11,000 species). These taxa were followed by a cluster composed of Mollusca (3,567 species), Platyhelminthes (2,292 species), Annelida (1,833 species), and Nematoda (1,447 species). All remaining groups had less than 1,000 species reported in Brazil, with Cnidaria (831 species), Porifera (628 species), Rotifera (606 species), and Bryozoa (520 species) representing those with more than 500 species. Analysis of the CTFB database can facilitate and direct efforts towards the discovery of new species in Brazil, but it is also fundamental in providing the best available list of valid nominal species to users, including those in science, health, conservation efforts, and any initiative involving animals. The importance of the CTFB is evidenced by the elevated number of citations in the scientific literature in diverse areas of biology, law, anthropology, education, forensic science, and veterinary science, among others

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

The original version of this article unfortunately contained a mistake

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat