Assessing roost disturbance of straw-coloured fruit bats (Eidolon helvum) through tri-axial acceleration

Tese de mestrado, Biologia da Conservação, Universidade de Lisboa, Faculdade de Ciências, 2019A perturbação humana em animais selvagens é uma ameaça que causa crescente preocupação. Apesar da perturbação poder ter causas naturais (e.g. eventos climáticos), esta está mais frequentemente relacionada com actividades humanas, como lazer, caça, ruído associado a centros urbanos e alterações ao nível da paisagem. O rápido crescimento da população humana, consequente expansão de meios urbanos e urbanização de meios rurais, leva a que o contacto entre seres humanos e animais selvagens seja mais frequente, aumentando o risco de perturbação da fauna. A perturbação pode desencadear respostas fisiológicas e comportamentais, podendo causar alterações no comportamento alimentar, sucesso reprodutivo, condição corporal, ou mesmo levar à morte dos indivíduos. Desta forma, a perturbação pode conduzir mudanças na abundância, distribuição e riqueza das espécies. Apesar da ameaça que representa, o estudo da perturbação em animais selvagens continua a revelar-se um desafio para a comunidade científica. Em parte, porque as respostas à perturbação tendem a ser específicas de cada espécie, mas também devido a limitações metodológicas. Actualmente, muitos dos estudos sobre perturbação da fauna, avaliam a perturbação através de alterações comportamentais nos indivíduos, uma vez que as respostas comportamentais à perturbação são as mais comuns e facilmente identificáveis. Dentro das respostas comportamentais, a fuga - que em morcegos e aves se traduz em voo - é a resposta mais frequentemente utilizada. Este comportamento é muitas vezes identificado através de observação directa, ainda que seja reconhecido que a presença do observador pode também causar perturbação, enviesando os resultados. Novos desenvolvimentos tecnológicos permitem identificar e quantificar as reacções à perturbação através de telemetria e detectores de movimento por infravermelhos, removendo assim o impacto da presença do observador. Além disso, o contínuo desenvolvimento dos dispositivos e tecnologia de bio-logging permite a recolha remota de dados, num grande leque de espécies e em habitats que de outra forma seriam inacessíveis. Os dispositivos utilizados permitem a recolha de dados de GPS e aceleração tri-axial, e a integração destes dois tipos de dados permite contextualizar espacialmente os dados de comportamento, fornecendo informação sobre os uso de habitat e a identificação de áreas importantes para as espécies, como as áreas de alimentação, abrigo e reprodução. Dado que os voos são uma resposta comum à perturbação em aves e morcegos, e dada a capacidade da aceleração tri-axial para discriminar este comportamento, é possível fazer uso desta tecnologia para identificar voos e utilizá-los como proxy de perturbação. A perturbação pode afectar especialmente animais nocturnos e gregários, uma vez que o pico da actividade humana ocorre durante o dia, que corresponde ao período de repouso destes animais, e também porque estes tornam mais conspícuos quando agregados em colónias. Eidolon helvum (Kerr, 1792) é uma espécie de morcego frugívoro da família Pteropodidae, que se distribui amplamente pela África subsariana. Esta espécie forma colónias com milhares, em alguns casos milhões, de indivíduos, e tem actividade crepuscular e nocturna, sendo por isso um bom modelo para avaliar perturbação em abrigos diurnos. É capaz de grandes migrações e de percorrer longas distâncias para se alimentar, sendo uma espécie-chave para a dispersão de sementes em África. Actualmente, encontra-se classificada como “Quase Ameaçada” pela IUCN, em grande parte devido à sua caça. Este estudo tem como principal objectivo identificar as principais causas de perturbação de E. helvum nos seus abrigos, utilizando voos diurnos, identificados a partir de aceleração tri-axial, como proxy de perturbação. Além disto, espera-se avaliar a influência da perturbação no comportamento alimentar e utilização de locais de repouso diurno. Para concretizar estes objectivos, foram estudados morcegos em cinco colónias em África continental - duas em Kibi (Gana), uma em Accra (Gana), uma em Ouagadougou (Burkina Faso), e uma no Parque Nacional de Kasanka (Zâmbia). Os morcegos foram capturados nos abrigos, quando regressavam de se alimentar, e foi-lhes aplicado um datalogger que recolhia dados de GPS e aceleração tri-axial. No total, foram obtidas 167 observações a partir de 46 indivíduos. Os dados de aceleração tri-axial foram utilizados para identificar voos durante o dia, em detrimento de outros comportamentos. Os voos diurnos foram transformados numa variável binária, de presença/ausência de voos durante o dia, usada como proxy de perturbação. As localizações exactas dos abrigos foram obtidas através dos dados GPS, que permitiram identificar 25 novos abrigos (abrigos secundários) para além dos cinco abrigos principais, onde os morcegos foram capturados. Um conjunto de variáveis ambientais, climáticas e intrínsecas aos animais, assim como o tipo de abrigo (principal ou secundário), e a ocorrência de sessões de captura de morcegos para instalação de dataloggers, foram extraídas e utilizadas para modelar a presença de voos diurnos nos abrigos de E. helvum. O tipo de abrigo, principal ou secundário, mostrou ser um importante preditor para a presença de perturbação, e a probabilidade de voos diurnos foi maior nos abrigos principais. É possível que este resultado se deva a diferenças de conspicuidade entre tipos de abrigo. Embora nada se saiba sobre os abrigos secundários descobertos, é possível que estes locais sirvam de abrigos temporários para pequenos grupos, perto das áreas de alimentação. Em contraste, os abrigos principais albergavam grandes colónias de E. helvum, muito conspícuas e consequentemente mais susceptíveis a predação e perseguição humana. As sessões de captura para aplicação dos dataloggers nos abrigos principais também revelaram ser um bom preditor da presença de perturbação, sendo que a probabilidade de voos diurnos foi maior nos dias em que decorreram capturas. Este resultado é esperado, uma vez que as capturas podem causar uma perturbação directa nos morcegos, o que simultaneamente valida a abordagem metodológica usada neste estudo. O vento e a energia solar têm também algum poder preditivo na presença de voos diurnos, embora este seja mais evidente quando o efeito das sessões de capturas é removido da análise. O vento teve um efeito negativo e a energia solar um efeito positivo na presença de voos diurnos. Menor velocidade do vento pode levar a que os morcegos não consigam dissipar energia de forma tão eficiente, da mesma forma que maior energia solar pode aumentar o ganho de energia por radiação. Desta forma, a maior probabilidade de voos diurnos pode dever-se a comportamentos de termorregulação, em que os morcegos mudam de posições no abrigo, de forma a encontrarem refúgio em partes com maior ensombramento. Ao contrário do esperado, a perturbação (i.e., presença de voos diurnos) não parece ter efeito na distância percorrida na noite seguinte, nem parece explicar as mudanças de abrigo registadas neste estudo. Tanto a mudança de abrigo como a distância percorrida podem estar relacionadas com a disponibilidade de recursos, nomeadamente de áreas de alimentação, uma vez que parece haver uma relação entre a localização dos recursos alimentares e a localização dos abrigos noutras espécies de morcegos e de aves. Contudo, isto não significa que a perturbação não tem efeitos negativos nestes morcegos. A perturbação pode provocar outros efeitos nos indivíduos, como alterações no metabolismo, sistema imunitário ou reprodução, que não são identificáveis pelos parâmetros testados. Este estudo fornece uma avaliação da perturbação em abrigos diurnos de E. helvum e dos seus principais preditores, e revela 25 novas localizações de abrigos diurnos. Desta forma, os resultados deste estudo podem ser utilizados para aumentar a vigilância em abrigos principais, e servem de base para aumentar o conhecimento sobre a perturbação em abrigos de E. helvum e contribuir para a sua protecção. Por fim, este estudo fornece uma nova abordagem metodológica para identificar perturbação em abrigos diurnos, que pode ser aplicada em outras espécies de Pteropodidae ou mesmo noutras espécies coloniais, e assim avaliar uma das maiores ameaças que enfrentam: a perturbação.Disturbance of wildlife is a threat of growing concern. It can be caused by natural effects, such as climatic events and by human related activities. It can negatively impact wildlife, causing changes in body condition, activity patterns, foraging behaviour, and can lead to changes in species distribution and richness. Assessing disturbance on wildlife has proven to be challenging, as different species can have different responses to disturbance. However, behavioural responses are the most common and have been widely used to assess disturbance in birds and bats. This has been done mostly through direct observation, which may result in disturbance caused by the observer. Advances in bio-logging allow the remote collection of GPS and tri-axial acceleration data, removing the effect of the observer. Tri-axial acceleration can provide valuable information on behaviour, and its integration with GPS data may be used to identify important habitat areas (e.g. foraging and roosting areas). As flight is a common response to disturbance in bats and birds, and tri-axial data can discriminate flight behaviour, daytime flights may be used as a proxy for disturbance. Therefore, this study aims to assess disturbance of straw-coloured fruit bats (Eidolon helvum) in day roosts across continental Africa and its most important predictors, using daytime flight as a proxy of disturbance. Tri-axial acceleration and GPS data was retrieved from 46 bats captured in five different colonies, located in Ghana, Burkina Faso and Zambia. In addition to the five main roosts where bats were captured, 25 other roosting locations were found and classified as secondary roosts. The results show that main roosts are good predictors of daytime disturbance, possibly due to increased conspicuousness and consequent human predation. Capture events for bat sampling were also good predictors, and the probability of daytime flight was higher in days when captures were conducted. Wind speed had a negative effect, and solar energy a positive effect on presence of daytime flights. Lower wind speed and higher solar energy may lead bats to exhibit thermoregulatory behaviours, translated in flights to change towards more shaded positions in the roost. Disturbance, as measured, appears to have no effect on the distance travelled by the bat in the following night, nor could it explain the changes of roost recorded. This study was able to successfully identify day roost disturbance in E. helvum, using daytime flights as a proxy, and to identify important predictors of disturbance. Ultimately, it provides a new methodological approach to assess day roost disturbance, which can be applied to other Pteropodidae or other colonial species

Assessing roost disturbance of straw-coloured fruit bats (Eidolon helvum) through tri-axial acceleration

The disturbance of wildlife by humans is a worldwide phenomenon that contributes to the loss of biodiversity. It can impact animals' behaviour and physiology, and this can lead to changes in species distribution and richness. Wildlife disturbance has mostly been assessed through direct observation. However, advances in bio-logging provide a new range of sensors that may allow measuring disturbance of animals with high precision and remotely, and reducing the effects of human observers. We used tri-axial accelerometers to identify daytime flights of roosting straw-coloured fruit bats (Eidolon helvum), which were used as a proxy for roost disturbance. This bat species roosts on trees in large numbers (often reaching hundreds of thousands of animals), making them highly vulnerable to disturbance. We captured and tagged 46 straw-coloured fruit bats with dataloggers, containing a global positioning system (GPS) and an accelerometer, in five roosts in Ghana, Burkina Faso and Zambia. Daytime roost flights were identified from accelerometer signatures and modelled against our activity in the roosts during the days of trapping, as a predictor of roost disturbance, and natural stressors (solar irradiance, precipitation and wind speed). We found that daytime roost flight probability increased during days of trapping and with increasing solar irradiance (which may reflect the search for shade to prevent overheating). Our results validate the use of accelerometers to measure roost disturbance of straw-coloured fruit bats and suggest that these devices may be very useful in conservation monitoring programs for large fruit bat species.info:eu-repo/semantics/publishedVersio

Lipidomic signatures reveal seasonal shifts on the relative abundance of high-valued lipids from the brown algae Fucus vesiculosus

Fucus vesiculosus is an edible brown macroalga, with health benefits associated with its consumption and also a source of bioactive molecules. It is acknowledged that the biochemical composition of macroalgae changes when exposed to different environmental conditions occurring on different habitats, such as the water temperature, and light intensity. In the present study, the polar lipidome of Fucus vesiculosus was characterized for the first time using modern high-resolution HILIC-MS, and MS/MS approaches, to evaluate the phenotypic variability in two seasons of the year, e.g., winter and spring. A total of 187 molecular species were identified over eighteen classes of glycolipids, phospholipids and betaine lipids. Principal component analysis (PCA) multivariate statistical analysis and cluster analysis of polar lipid classes, polar lipid species and total fatty acids (FA) datasets, showed clustering according to the seasonal groups. While the lipid profile of Fucus vesiculosus harvested in the winter and spring yielded the same molecular species, the relative abundance of these species was significantly different. In the winter, changes were mainly due to the increased relative abundance of some molecular species of glycolipids and phospholipids, bearing octadeca(poly)enoic (18:3, 18:4) and eicosa(poly)enoic (20:4, 20:5) FA and betaine lipids species with short saturated FA (14:0) and polyunsaturated FA (PUFA). Importantly, glycolipids with n-3 PUFA and sulfolipids, have been reported to have important biological activities and therapeutic value. Overall, Fucus vesiculosus is a promising source of bioactive compounds that can be used as functional food or ingredients for human nutrition, feed, pharma, and cosmetic formulations. In this study, samples harvested in the winter season maximized yields of these bioactive components, when compared with samples harvested in the spring.publishe

Site-specific lipidomic signatures of sea lettuce (Ulva spp., Chlorophyta) hold the potential to trace their geographic origin

The wild harvest and aquaculture of Ulva spp. has deserved growing attention in Europe. However, the impact of geographical origin on the biochemical composition of different species and/or strains is yet to be described in detail. Hence, the present study aimed to detect the variability of the lipidome of different species and/or strains of Ulva originating from different geographic locations. We hypothesized that lipidomic signatures can be used to trace the geographic origin post-harvesting of these valuable green seaweeds. Ulva spp. was sampled from eight distinct ecosystems along the Atlantic Iberian coast and Ulva rigida was sourced from an aquaculture farm operating a land-based integrated production site. Results showed significant differences in the lipidomic profile displayed by Ulva spp. originating from different locations, namely, due to different levels of polyunsaturated betaine lipids and galactolipids; saturated betaine lipids and sulfolipids; and some phospholipid species. Overall, a set of 25 site-specific molecular lipid species provide a unique lipidomic signature for authentication and geographic origin certification of Ulva species. Present findings highlight the potential of lipidome plasticity as a proxy to fight fraudulent practices, but also to ensure quality control and prospect biomass for target bioactive compounds.publishe

Lipidomic signature of the green macroalgae Ulva rigida farmed in a sustainable integrated multi-trophic aquaculture

Ulva species, green macroalgae, are widely distributed across the globe, being one of the most heavily traded edible seaweeds. Nonetheless, although this genus has been largely used in scientific studies, its lipidome remains rather unexplored. The present study sheds light over the lipid profile of Ulva rigida produced in a land-based integrated multi-trophic aquaculture (IMTA) system using liquid chromatography coupled to high-resolution mass spectrometry for molecular lipid species identification. The lipidome of U. rigida revealed the presence of distinct beneficial n-3 fatty acids for human health, namely alpha-linoleic acid (ALA) and docosapentaenoic acid (DPA). A total of 87 molecular species of glycolipids, 58 molecular species of betaine lipids, and 57 molecular species of phospholipids were identified in the lipidome of U. rigida including some species bearing PUFA and with described bioactive properties. Overall, the present study contributes to the valorization and quality validation of sustainably farmed U. rigida.publishe

Lipidomics reveals similar changes in serum phospholipid signatures of overweight and obese pediatric subjects

Obesity is a public health problem and a risk factor for pathologies such type 2 diabetes mellitus, cardiovascular diseases, and nonalcoholic fatty liver disease. Given these clinical implications, there is a growing interest to understand the pathophysiological mechanism of obesity. Changes in lipid metabolism have been associated with obesity and obesity-related complications. However, changes in the lipid profile of obese children have been overlooked. In the present work, we analyzed the serum phospholipidome of overweight and obese children by HILIC-MS/MS and GC-MS. Using this approach, we have identified 165 lipid species belonging to the classes PC, PE, PS, PG, PI, LPC, and SM. The phospholipidome of overweight (OW) and obese (OB) children was significantly different from normal-weight children (control). Main differences were observed in the PI class that was less abundant in OW and OB children and some PS, PE, SM, and PC lipid species are upregulated in obese and overweight children. Although further studies are needed to clarify some association between phospholipid alterations and metabolic changes, our results highlight the alteration that occurs in the serum phospholipid profile in obesity in children.publishe

Polar lipids of commercial Ulva spp. of different origins: profiling and relevance for seaweed valorization

Macroalgae of the genus Ulva have long been used as human food. Local environmental conditions, among other factors, can have an impact on their nutrient and phytochemical composition, as well as on the value of the seaweed for food and non-food applications. This study is the first to initiate a comparison between commercial Ulva spp. from different European origins, France (FR, wild-harvested Ulva spp.), and Portugal (PT, farm-raised Ulva rigida), in terms of proximate composition, esterified fatty acids (FA), and polar lipids. The ash content was higher in PT samples, while FR samples had higher levels of proteins, lipids, and carbohydrates and other compounds. The profile of esterified FA, as well as FA-containing polar lipids at the class and species levels were also significantly different. The FR samples showed about three-fold higher amount of n-3 polyunsaturated FA, while PT samples showed two-fold higher content of monounsaturated FA. Quantification of glycolipids and phospholipids revealed, respectively, two-fold and three-fold higher levels in PT samples. Despite the differences found, the polar lipids identified in both batches included some lipid species with recognized bioactivity, valuing Ulva biomass with functional properties, increasing their added value, and promoting new applications, namely in nutraceutical and food markets.UIDB/50011/2020+UIDP/50011/2020, UID/QUI/00062/2019, UIDB/50006/2020, UIDB/50017/2020+UIDP/50017/2020, LISBOA-01-0145-FEDER-402-022125, POCI-01-0145-FEDER-030962, BPD/UI51/5041/2017, BPD/UI51/5042/2018; EC/H2020/727892/EUinfo:eu-repo/semantics/publishedVersio

Errors in protein synthesis increase the level of saturated fatty acids and affect the overall lipid profiles of yeast

The occurrence of protein synthesis errors (mistranslation) above the typical mean mistranslation level of 10-4 is mostly deleterious to yeast, zebrafish and mammal cells. Previous yeast studies have shown that mistranslation affects fitness and deregulates genes related to lipid metabolism, but there is no experimental proof that such errors alter yeast lipid profiles. We engineered yeast strains to misincorporate serine at alanine and glycine sites on a global scale and evaluated the putative effects on the lipidome. Lipids from whole cells were extracted and analysed by thin layer chromatography (TLC), liquid chromatography-mass spectrometry(LC-MS) and gas chromatography (GC). Oxidative damage, fatty acid desaturation and membrane fluidity changes were screened to identify putative alterations in lipid profiles in both logarithmic (fermentative) and post-diauxic shift (respiratory) phases. There were alterations in several lipid classes, namely lyso-phosphatidylcholine, phosphatidic acid, phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine, and triglyceride, and in the fatty acid profiles, namely C16:1, C16:0, C18:1 and C18:0. Overall, the relative content of lipid species with saturated FA increased in detriment of those with unsaturated fatty acids. The expression of the OLE1 mRNA was deregulated, but phospholipid fluidity changes were not observed. These data expand current knowledge of mistranslation biology and highlight its putative roles in human diseases.publishe

Maternal γδ T cells shape offspring pulmonary type 2 immunity in a microbiota-dependent manner.

Immune development is profoundly influenced by vertically transferred cues. However, little is known about how maternal innate-like lymphocytes regulate offspring immunity. Here, we show that mice born from γδ T cell-deficient (TCRδ-/-) dams display an increase in first-breath-induced inflammation, with a pulmonary milieu selectively enriched in type 2 cytokines and type 2-polarized immune cells, when compared with the progeny of γδ T cell-sufficient dams. Upon helminth infection, mice born from TCRδ-/- dams sustain an increased type 2 inflammatory response. This is independent of the genotype of the pups. Instead, the offspring of TCRδ-/- dams harbors a distinct intestinal microbiota, acquired during birth and fostering, and decreased levels of intestinal short-chain fatty acids (SCFAs), such as pentanoate and hexanoate. Importantly, exogenous SCFA supplementation inhibits type 2 innate lymphoid cell function and suppresses first-breath- and infection-induced inflammation. Taken together, our findings unravel a maternal γδ T cell-microbiota-SCFA axis regulating neonatal lung immunity

Cuidados com a pele durante a pandemia de coronavírus: orientações para prevenir lesões de pele relacionadas ao uso de EPIs e à lavagem de mãos

A Liga Acadêmica de Cuidados com a Pele e Feridas Cuidarte (LACPF-CuidArte) reuniu, nesta cartilha, algumas recomendações de cuidados com a pele durante a pandemia de Coronavírus, com estratégias para prevenir e lidar com as doenças cutâneas relacionadas ao coronavírus e ao uso prolongado de EPIs