3,670 research outputs found

    Not so monochromatic: Size-dependency of both sex and color in the cleaner wrasse Labroides dimidiatus

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    In marine interspecific cleaning mutualisms, small fish known as “cleaners” inspect the surface, gills and sometimes the mouth of “client” reef fish, eating ectoparasites, mucus, scales and dead or infected tissue. These cleaner fish species share similar vivid coloration that makes them recognizable by clients. To gain insight on additional communication roles of cleaner fish color, we tested if differences in color among cleaner wrasse Labroides dimidiatus individuals captured from the wild are explained by sex, body size or parasite loads. We found that males were larger, heavier and tended to have more saturated blue tails than females. We also found blue color saturation to be positively correlated with size, and that this size-dependence explains the trend for the sexes to differ in color. Parasite loads did not predict individual differences in color, but fish in our sample were not heavily parasitized. Other color traits (including yellow color saturation and black color brightness) did not differ between the sexes and were associated with morphological differences. Size-dependence of blue color may thus suggest that it is a condition-dependent signal that could be used in various types of inter- and intraspecific social interactions

    What did we learn after the 2020 pandemic? Seroprevalence of SARS-CoV-2 infection in a North region of Portugal during 3rd lockdown

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    Background: Serological studies of antibody prevalence in response to infection with the acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are useful to monitor the epidemic progression of the disease and to evaluate infection rates. In this study, we estimated the prevalence of anti-SARS-CoV-2 antibodies (IgM and IgG) in a Portuguese sub-district, during National lockdown - January-March 2021.Methods: In the seroepidemiological survey participants were tested for SARS-CoV-2 antibodies (IgM and IgG), in blood samples. The estimated seroprevalence and results were stratified by age, gender, education, occupational exposure, symptoms and previous SARS-CoV-2 infection.Results: Seroprevalence was 41.3%, (15.7% IgG positive, 11.6% IgM positive and 14% positive for both). The majority (74%) of the participants were working presentially and did the serological assay because they had either symptoms / positive contact (90%) or had a previous positive antigen test (36%). From all the seropositive cases only 44% were symptomatic. Our results show that seroprevalence of SARS -CoV-2 is high in the North, in parallel with the National Surveillance System. Seroprevalence was higher in woman than man and in adults older than 21. Almost all the people with symptoms or a positive contact had a positive test and were working at their regular places of work reflecting the danger of occupational exposure. Conclusions: These results suggest that, between January and March 2021, the restriction conditions were effective but unable to stop SARS-CoV-2 epidemic. It is essential to assess SARS-CoV-2 seroprevalence to monitor population immunity and if it lasts, specially from new COVID 19 variants

    Rheumatoid arthritis, multiple sclerosis and lupus: key points from the COVID-19 era

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    The purpose of this work was to analyse published data on rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and multiple sclerosis (MS) and SARS-CoV-2 infection: susceptibility, post-infection autoimmune disease (AD) exacerbation, immunosuppressive therapies and long COVID. Supported by PICO strategy, two independent reviewers conducted the research in the PubMed/Medline database from January 2020 to June 2022 and included 16 articles on RA, 25 on MS and 12 on SLE. The quality assessment of the studies was performed using criteria from the National Institute of Health. Patients with RA or SLE had increased susceptibility to contracting SARS-CoV-2. It was higher in RA and increased with the patients’ comorbidities. For MS, susceptibility to SARS-CoV-2 was similar to the general population. Post-infection AD exacerbation occurred in AR, SLE and MS with an increased number of hospitalisations and deaths. Regarding therapies, in RA the use of glucocorticoids (GC) was associated with a worsening of the infection. A more severe clinical picture was associated with anti-CD20 in SLE and with anti-CD20 and methylprednisolone in MS. Considering long COVID, RA and SLE patients had a higher risk of complications opposite to MS patients. There was a higher susceptibility to SARS-CoV-2 infection in rheumatological diseases AR and SLE, exacerbated by age and comorbidities. For RA and MS, GC aggravated the infection and for SLE and MS anti-CD20 antibodies use. In all AD there was exacerbation and worsening of the clinical picture translated in long COVID, the latter with MS exception

    Hyperbolicity preserving HLL solver for two-layer shallow-water equations applied to dam-break flows

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    River morphodynamics and sediment transportDebris and hyperconcentrated flow

    Teaching & Learning Forum@UA: book of posters

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    Sem resumo disponível.publishe

    Vanadate oligomers: in vivo effects in hepatic vanadium accumulation and stress markers

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    The formation of vanadate oligomeric species is often disregarded in studies on vanadate effects in biological systems, particularly in vivo, even though they may interact with high affinity with many proteins. We report the effects in fish hepatic tissue of an acute intravenous exposure (12, 24 h and 7 days) to two vanadium(V) solutions, metavanadate and decavanadate, containing different vanadate oligomers administered at sub-lethal concentration (5 mM; 1 mg/kg). Decavanadate solution promotes a 5-fold increase (0.135 ± 0.053 lg V 1 dry tissues) in the vanadium content of the mitochondrial fraction 7 days after exposition, whereas no effects were observed after metavanadate solution administration. Reduced glutathione (GSH) levels did not change and the overall reactive oxygen species (ROS) production was decreased by 30% 24 h after decavanadate administration, while for metavanadate, GSH levels increased 35%, the overall ROS production was depressed by 40% and mitochondrial superoxide anion production decreased 45%. Decavanadate intoxication did not induce changes in the rate of lipid peroxidation till 12 h, but later increased 80%, which is similar to the increase observed for metavanadate after 24 h. Decameric vanadate administration clearly induces different effects than the other vanadate oligomeric species, pointing out the importance of taking into account the different vanadate oligomers in the evaluation of vanadium(V) effects in biological systems

    Influência da alexitimia nos processos atencionais: A deteção de expressões faciais emocionais

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    Alexithymia is characterized by difficulties in emotional processing and facial expression recognition, essential processes in interpersonal relationship. In this study we intended to evaluate if facial expressions processing in individuals with high levels of alexithymia, especially negative emotional expressions (anger, disgust), is distinguished from the processing done by individuals with low levels of alexithymia. The participants (67 women) performed a visual search task in which sets of emotional facial expressions (happyness, anger and disgust) were presented among neutral facial expressions. The participants’ task was to detect the presence or absence of these emotional facial expressions as quickly and accurately as possible. The results revealed no significant differences between the target groups. However, there was a differential processing of the emotional facial expressions according to the face gender. The negative emotional expressions on faces of men were promptly detected. On the other hand, the processing of faces of women who expressed anger led to a greater proportion of errors. The evolutionary assumptions associated with the processing of negative emotions, which the literature in the relationship between emotion and attention indicates as being an adaptive process in the general population, may explain the absence of significant effects between the groups with high and low levels of alexithymia.A alexitimia carateriza-se pela dificuldade no processamento emocional e reconhecimento de expressões faciais, processos indispensáveis no relacionamento interpessoal. Neste estudo, pretendemos avaliar se o processamento de expressões faciais em indivíduos com altos níveis de alexitimia, sobretudo de expressões com cariz emocional negativo (raiva, nojo), é diferenciado do processamento efetuado por indivíduos com baixos níveis de alexitimia. Os participantes (67 mulheres) realizaram uma tarefa de procura visual onde se apresentavam conjuntos de expressões faciais emocionais (alegria, raiva, nojo), tendo os participantes de detetar de modo rápido e preciso a presença (ou ausência) destas expressões apresentadas entre expressões faciais neutras. Os resultados não revelaram quaisquer diferenças significativas entre os grupos. Contudo, verificou-se um processamento diferencial das expressões faciais emocionais em função do género da face. As expressões emocionais negativas em faces de homens foram mais rapidamente detetadas. Por outro lado, o processamento de faces de mulheres que expressavam raiva conduziu a uma maior proporção de erros. Os pressupostos evolutivos associados ao processamento das emoções negativas, que a literatura na área da relação entre a emoção e a atenção aponta como adaptativa na população em geral, poderá explicar a ausência de efeitos significativos entre o grupo com altos e baixos níveis de alexitimia

    Characterisation of physiological responses to odours in autism spectrum disorders: a preliminary study

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    Abnormal sensory perception is among the earliest symptoms of autism spectrum disorders (ASD). Despite mixed findings, olfactory perception seems to be altered in ASD. There is also evidence that automatic responses to odours can serve as biomarkers of ASD. However, this potential use of odour-based biomarkers for ASD is still underexplored. In this study, we aimed to investigate whether physiological responses to social and non-social odours, measured with electrocardiography (ECG) and facial electromyography (EMG), can be used to characterise and predict ASD in adults. For that, we extracted 32 signal features from a previously collected database of 11 adults with ASD and 48 adults with typical development (TD). Firstly, non-parametric tests were performed, showing significant differences between the ASD and the TD groups in 10 features. Secondly, a k-nearest-neighbour classifier with a leave-one-out strategy was employed, obtaining an F1-score of 67%. Although caution is needed due to the small sample size, this study provides preliminary evidence supporting the use of physiological responses to social and non-social odours as a potential diagnostic tool for ASD in adults.This work is also funded by national funds, European Regional Development Fund, FSE through COMPETE2020, through FCT, in the scope of the framework contract foreseen in the numbers 4, 5, and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19.publishe

    Multimodal emotion evaluation: a physiological model for cost-effective emotion classification

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    Emotional responses are associated with distinct body alterations and are crucial to foster adaptive responses, well-being, and survival. Emotion identification may improve peoples' emotion regulation strategies and interaction with multiple life contexts. Several studies have investigated emotion classification systems, but most of them are based on the analysis of only one, a few, or isolated physiological signals. Understanding how informative the individual signals are and how their combination works would allow to develop more cost-effective, informative, and objective systems for emotion detection, processing, and interpretation. In the present work, electrocardiogram, electromyogram, and electrodermal activity were processed in order to find a physiological model of emotions. Both a unimodal and a multimodal approach were used to analyze what signal, or combination of signals, may better describe an emotional response, using a sample of 55 healthy subjects. The method was divided in: (1) signal preprocessing; (2) feature extraction; (3) classification using random forest and neural networks. Results suggest that the electrocardiogram (ECG) signal is the most effective for emotion classification. Yet, the combination of all signals provides the best emotion identification performance, with all signals providing crucial information for the system. This physiological model of emotions has important research and clinical implications, by providing valuable information about the value and weight of physiological signals for emotional classification, which can critically drive effective evaluation, monitoring and intervention, regarding emotional processing and regulation, considering multiple contexts.publishe

    Fast detector/first responder : interactions between the superior colliculus-pulvinar pathway and stimuli relevant to primates

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    Primates are distinguished from other mammals by their heavy reliance on the visual sense, which occurred as a result of natural selection continually favoring those individuals whose visual systems were more responsive to challenges in the natural world. Here we describe two independent but also interrelated visual systems, one cortical and the other subcortical, both of which have been modified and expanded in primates for different functions. Available evidence suggests that while the cortical visual system mainly functions to give primates the ability to assess and adjust to fluid social and ecological environments, the subcortical visual system appears to function as a rapid detector and first responder when time is of the essence, i.e., when survival requires very quick action. We focus here on the subcortical visual system with a review of behavioral and neurophysiological evidence that demonstrates its sensitivity to particular, often emotionally charged, ecological and social stimuli, i.e., snakes and fearful and aggressive facial expressions in conspecifics. We also review the literature on subcortical involvement during another, less emotional, situation that requires rapid detection and response—visually guided reaching and grasping during locomotion—to further emphasize our argument that the subcortical visual system evolved as a rapid detector/first responder, a function that remains in place today. Finally, we argue that investigating deficits in this subcortical system may provide greater understanding of Parkinson's disease and Autism Spectrum disorders (ASD)
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