Browsing by Author "Bispo, Regina"
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- Accounting for animal density gradients using independent information in distance sampling surveysPublication . Marques, Tiago A.; Buckland, Stephen T.; Bispo, Regina; Howland, BrettDistance sampling is extensively used for estimating animal density or abundance. Conventional methods assume that location of line or point transects is random with respect to the animal population, yet transects are often placed along linear features such as roads, rivers or shorelines that do not randomly sample the study region, resulting in biased estimates of abundance. If it is possible to collect additional data that allow an animal density gradient with respect to the transects to be modelled, we show how to extend the conventional distance sampling likelihood to give asymptotically unbiased estimates of density for the covered area. We illustrate the proposed methods using data for a kangaroo population surveyed by line transects laid along tracks, for which the true density is known from an independent source, and the density gradient with respect to the tracks is estimated from a sample of GPS collared animals. For this example, density of animals increases with distance from the tracks, so that detection probability is overestimated and density underestimated if the non-random location of transects is ignored. When we account for the density gradient, there is no evidence of bias in the abundance estimate. We end with a list of practical recommendations to investigators conducting distance sampling surveys where density gradients could be an issue.
- Enhancing carcass removal trials at three wind energy facilities in PortugalPublication . Bernardino, Joana; Bispo, Regina; Torres, Paulo; Rebelo, Rui; Mascarenhas, Miguel; Costa, HugoDuring the last years there has been a significant worldwide increase in the number of wind farms. This kind of energy can have negative impacts, such as the direct mortality or lethal injury of birds and bats caused by collision with wind turbines. In order to evaluate bird (or bat) mortality regarding wind power generation facilities, strict monitoring protocols are required which must take into account the possibility of carcass removal by scavenging animals or decomposition before the monitoring session. For this purpose, carcass removal trials with 180 carcasses representing three size classes (small, medium and large) were conducted in two seasons (Spring and Autumn) at three wind farms located in the central region of Portugal. No significant differences were found between removal rates of different wind farms or size classes contrarily to seasons, which presented an average carcass removal time of 3.9 and 4.6 days, respectively for Spring and Autumn. The results of the present study showed the importance of trials to estimate the carcass removal rates, which influences the survey effort management and consequently the monitoring protocols. The experimental design for future trials in the same region should account for season effect and be conducted using daily checks of the carcasses for, at least, 15 days.
- Estimating bird and bat fatality at wind farms: from formula-based methods to models to assess impact significancePublication . Marques, Joana; Rodrigues, Luísa; Silva, Maria João; Santos, Joana; Bispo, Regina; Bernardino, Joana
- Foraging behaviour, swimming performance and malformations of early stages of commercially important fishes under ocean acidification and warmingPublication . Pimentel, Marta; Faleiro, Filipa; Marques, Tiago A.; Bispo, Regina; Dionísio, Gisela João Ribeiro Lemos; Faria, Ana Margarida; Machado, Jorge; Peck, Myron A.; Pörtner, Hans; Ferreira, Pedro Marques Pousão; Gonçalves, Emanuel João; Rosa, RuiEarly life stages of many marine organisms are being challenged by climate change, but little is known about their capacity to tolerate future ocean conditions. Here we investigated a comprehensive set of biological responses of larvae of two commercially important teleost fishes, Sparus aurata (gilthead seabream) and Argyrosomus regius (meagre), after exposure to future predictions of ocean warming (+4 °C) and acidification (ΔpH= 0.5). The combined effect of warming and hypercapnia elicited a decrease in the hatching success (by 26.4 and 14.3 % for S. aurata and A. regius, respectively) and larval survival (by half) in both species. The length for newly-hatched larvae was not significantly affected, but a significant effect of hypercapnia was found on larval growth. However, while S. aurata growth was reduced (24.8–36.4 % lower), A. regius growth slightly increased (3.2–12.9 % higher) under such condition. Under acidification, larvae of both species spent less time swimming, and displayed reduced attack and capture rates of prey. The impact of warming on these behavioural traits was opposite but less evident. While not studied in A. regius, the incidence of body malformations in S. aurata larvae increased significantly (more than tripled) under warmer and hypercapnic conditions. These morphological impairments and behavioural changes are expected to affect larval performance and recruitment success, and further influence the abundance of fish stocks and the population structure of these commercially important fish species. However, given the pace of ocean climate change, it is important not to forget that species may have the opportunity to acclimate and adapt.
- Modeling carcass removal time for avian mortality assessment in wind farms using survival analysisPublication . Bispo, Regina; Bernardino, Joana; Marques, Tiago A.; Pestana, DinisIn monitoring studies at wind farms, the estimation of bird and bat mortality caused by collision must take into account carcass removal by scavengers or decomposition. In this paper we propose the use of survival analysis techniques to model the time of carcass removal. The proposed method is applied to data collected in ten Portuguesewind farms.We present and compare results obtained from semiparametric and parametric models assuming four main competing lifetime distributions (exponential, Weibull, log-logistic and log-normal). Both homogeneous parametric models and accelerated failure time models were used. The fitted models enabled the estimation of the carcass persistence rates and the calculation of a scavenging correction factor for avian mortality estimation. Additionally, we discuss the impact that the distributional assumption can have on parameter estimation. The proposed methodology integrates the survival probability estimation problem with the analysis of covariate effects. Estimation is based on the most suitable model while simultaneously accounting for censored observations, diminishing scavenging rate estimation bias. Additionally, the method establishes a standardized statistical procedure for the analysis of carcass removal time in subsequent studies.
- Mudanças resultantes de um programa comunitário de prevenção dos abusos sexuais de crianças (ASC)Publication . Maria, Susana Gabriela da Silva; Ornelas, José; Bispo, ReginaOs programas de prevenção dos ASC têm recebido algumas críticas e comentários negativos por parte de alguns teóricos e investigadores na área. O nosso objectivo é apresentarmos um estudo em que nos propomos analisar o impacto de um programa comunitário de prevenção dos ASC desenvolvido a partir do contexto escolar e envolvendo: crianças, familiares e profissionais. Avaliaremos o impacto que este programa tem nos participantes em termos dos seus conhecimentos e competências relativamente à prevenção e intervenção nos ASC. Espera-se que os participantes demonstrem níveis significativamente mais elevados de conhecimentos e competências mais adequadas, relativamente à prevenção e intervenção nos ASC, após o seu envolvimento no programa quando comparados com os níveis anteriores. Consequentemente, o programa de prevenção em causa funcionará potencialmente como um redutor de risco e poderá contribuir positivamente para criar factores protectores nas potenciais vítimas, nas famílias e nos vários contextos do quotidiano, ou seja, na comunidade.
- Small pelagics in a changing ocean : Biological responses of sardine early stages to warmingPublication . Faleiro, Filipa; Pimentel, Marta; Pegado, Maria Rita; Bispo, Regina; Lopes, Ana Rita; Diniz, Mário S.; Rosa, RuiSmall pelagic fishes are known to respond rapidly to changes in ocean climate. In this study, we evaluate the effects of future environmental warming (+2°C) during the early ontogeny of the European sardine, Sardina pilchardus. Warming reduced the survival of 30-day-old larvae by half. Length at hatching increased with temperature as expected, but no significant effect was observed on the length and growth at 30 days post-hatching. Warming did not significantly affect the thermal tolerance of sardine larvae, even though the mean lethal temperature increased by 1°C. In the warm conditions, sardine larvae showed signs of thermal stress, indicated by a pronounced increase in larval metabolism (Q 10 = 7.9) and a 45% increase in the heat shock response. Lipid peroxidation was not significantly affected by the higher temperature, even though the mean value doubled. Warming did not affect the time larvae spent swimming, but decreased by 36% the frequency of prey attacks. Given the key role of these small pelagics in the trophic dynamics off the Western Iberian upwelling ecosystem, the negative effects of warming on the early stages may have important implications for fish recruitment and ecosystem structure.
- Statistical power of goodness-of-fit tests based on the empirical distribution function for type-I right-censored dataPublication . Bispo, Regina; Marques, Tiago A.; Pestana, DinisIn this study, the power of common goodness-of-fit (GoF) statistics based on the empirical distribution function (EDF) was simulated for single type-I right-censored data. The statistical power of the Kolmogorov–Smirnov, Cramér–von Mises and Anderson–Darling statistics was investigated by varying the null and the alternative distributions, the sample size, the degree of censoring and the significance level. The exponential,Weibull, log-logistic and log-normal lifetime distributions were considered as they are among the most frequently distributions used when modelling censored data. We conclude by giving some general recommendations for testing the distributional assumption of parametric survival models in homogeneous populations when using EDF-based GoF statistics.
- Tarefas matemáticas e desenvolvimento do conhecimento matemático no 5.º ano de escolaridadePublication . Bispo, Regina; Ramalho, Glória; Henriques, NunoAs tarefas matemáticas providenciam o contexto no qual os estudantes aprendem matemática. Embora sejam muitos os factores que influenciam o processo de aprendizagem da matemática, as tarefas propostas aos estudantes são determinantes na medida em que actuam como “causas próximais” da aprendizagem. O nível de exigência cognitiva e a promoção do processo de matematização são características fundamentais nas tarefas propostas aos alunos. Este estudo incide sobre a análise das tarefas matemáticas propostas por professores a alunos do 5.º ano de escolaridade. Os itens foram analisados de acordo com e estrutura teórica desenvolvida no âmbito do programa PISA da OECD. Os níveis de exigência cognitiva mais elevados foram encontrados no desenvolvimento das competências matemáticas Comunicação e Pensamento e Raciocínio, sendo estes significativamente maiores que os associados às competências Argumentação, Colocação e Resolução de problemas, Modelação e Uso de auxiliares e instrumentos. A competência matemática menos trabalhada nos itens analisados é o Uso de linguagem simbólica, formal e técnica. A análise dos dados mostrou que a maioria das tarefas incluem-se no grupo das tarefas de Reprodução. Em conclusão, o estudo evidencia que a grande maioria das tarefas não usam contextos realistas e, predominantemente, conduzem os estudantes a seleccionar procedimentos e algoritmos de resolução pré-definidos. Palavras-chave: Tarefas matemáticas, ensino da matemática, competências matemáticas, níveis de exigência cognitiva.
- Use of complementary and alternative medicine in a sample of women with breast cancerPublication . Vidal, Mariana; Carvalho, Cláudia Maria Constante Ferreira de; Bispo, ReginaAbstract This study aims to examine the usage of complementary and alternative medicine (CAM) on a sample of Portuguese women with history of breast cancer. A total of 107 women with history of breast cancer attending Movimento Vencer e Viver Lisboa responded to a questionnaire designed to assess the use of CAM, as well as other variables, such as satisfaction with conventional care, health perception, perceived control over cancer, and health status (body mass index [BMI], smoking and alcohol consumption, hours of sleep, and physical activity). Forty-eight percent of the participants had used some kind of CAM in the past 12 months. The perceived control over cancer was significantly associated with CAM use (odds ratio [OR] = 1.5; 95% confidence interval [CI] = [1.2, 1.9]). CAM use was more prevalent among women aged 30 to 39 years, single, with high education, and a monthly income of 2,500€ to 2,999€. The CAM used most often were natural products, along with psychotherapy, breathing exercises, and meditation. The main reason mentioned for its use was the improved sense of wellbeing, and it was interesting to note that 60% of the participants who used CAM did not discuss it with their physicians. The findings support previous data that suggest that the participants’ perceived control over their cancer is a significant predictor of CAM usage, and more than half of the patients did not discuss CAM usage with their physician. Further studies with larger samples of cancer patients are warranted.