http://hdl.handle.net/10174/42 2026-04-10T14:50:53Z http://hdl.handle.net/10174/41771 Title: Seroepidemiology of Rickettsia conorii in dogs in Portugal: a comprehensive 12-year retrospective study (2013–2024) Authors: Lopes, Ricardo; Carvalho, Hugo L; Garces, Andreia; Fernandes, Cátia; Lopes; Martins, A; Duarte, Elsa Leclerc; Cardoso, Luis Lucas; Coelho, AC Abstract: Background Mediterranean spotted fever (MSF), caused by Rickettsia conorii, is a zoonotic tick-borne disease of important public health concern, particularly in the Mediterranean Basin. Dogs serve as key sentinels for MSF due to their exposure to vector ticks and close contact with humans. To date, no comprehensive study in Portugal has investigated epidemiological risk factors in dogs infected with or exposed to R. conorii. Methods Seropositivity to R. conorii was determined using an immunofluorescence antibody test (IFAT), with titres categorised as negative, low positive, moderate positive and high positive. Statistical analyses included the chisquared test and univariable logistic regression to assess associations between seropositivity and geographical region, season, month, size, breed, sex and age. Results This study analysed 2457 canine samples submitted from 228 veterinary medical centres across mainland Portugal and insular autonomous regions between 2013 and 2024. The overall seroprevalence of R. conorii was 27.0% (95% confidence interval [CI] 25.3–28.8). Significant differences in seroprevalence were observed amongst regions, with the highest values in the Algarve (48.0%; odds ratio [OR] 3.1, 95% CI 2.2–4.4, P<0.001), Alentejo (35.0%; OR1.8, 95% CI 0.7−4.6, P=0.210) and Centre (33.8%; OR 1.7, 95% CI 1.4–2.1, P<0.001) regions. Giant breeds had the highest seroprevalence (33.0%; OR3.0, 95% CI 1.3–6.6, P=0.008), with Irish Setter and Miniature Schnauzer identified as highrisk breeds (75.0%; OR27.0, 95% CI 1.3–578.4, P=0.035). Male dogs had higher seroprevalence (28.9%; OR1.2, 95% CI 1.0–1.5, P=0.023), whilst geriatric dogs showed the highest risk of exposure to or infection with R. conorii (34.6%; OR5.2, 95% CI 2.8–9.8, P<0.001). Conclusions This study represents the most extensive epidemiological analysis of canine MSF in Portugal. The findings highlight associations between R. conorii seropositivity and geographical region, size, breed, sex and age of dogs, advancing the limited knowledge on the epidemiology of R. conorii in Portugal and underscoring the need for regional surveillance and targeted prevention to reduce infection risks in both canine populations and public health contexts. 2025-01-01T00:00:00Z http://hdl.handle.net/10174/41736 Title: Walnut Shells to Enhance Substrate Sustainability: Effects on Lettuce Yield, Nitrate Accumulation, and Phytochemical Content. Authors: Machado, Rui; Alves-Pereira, Isabel; Grilo, Ana; Esteves, Pedro; Rui, Ferreira Abstract: Coir is widely used as a soilless substrate yet partially replacing it with walnut shells in coir-based mixes may improve the sustainability of lettuce production and quality. This study evaluated the effect of incorporating walnut shells, with or without biochar, into coir-based substrates on lettuce yield and quality. Lettuce was grown in five substrates: coir (C), three coir–walnut mixes (1:1, 1:0.5, and 1:0.25 v/v), and one coir–walnut–biochar mix (C:W:B, 10:1.5:1 v/v). Increasing the walnut-shell proportion increased the cumulative leaching fraction, likely because of the coarse walnut particles, and reduced head fresh weight. However, shoot dry weight in the 1:0.5 and 1:0.25 mixes was similar to that in coir alone and reduced leaf nitrate content. In contrast, the C:W:B mix maintained head fresh weight (7.1 kg m→2) and shoot dry weight comparable to coir, while markedly lowering leaf nitrate concentration from 4130 to below 200 mg NO3→ kg→1 fresh weight. Leaf nitrate content increased linearly with shoot Zn uptake, suggesting a Zn-mediated control of nitrate accumulation. The coir–walnut–biochar mix emerges as a suitable alternative to pure coir, as it maintains lettuce productivity, reduces leaf nitrate accumulation, enhances anthocyanin content, and reflects more favorable physiological conditions by not requiring a strong activation of antioxidant defenses. 2026-01-07T00:00:00Z http://hdl.handle.net/10174/41698 Title: The critical challenge of nonstationarity in ecological modelling Authors: Wang, Hsiao-Hsuan; Alagador, Diogo Abstract: Ecological systems are dynamic and shaped by complex interactions that vary across space, time, and levels of biological organization (Fischer et al., 2025). Therefore, most ecological systems display confounding spatial and temporal trends, such as nonstationarity, at some scale. Nonstationarity (abrupt change in the mean or variance of a system property in space or time) can result from variation in environmental conditions (e.g., topography) or occurrence of a disturbance (e. g., a flood). Models of systems exhibiting nonstationarity that are based on non-spatial and equilibrium representations of system properties can produce misleading inferences and predictions. The potential consequences include misidentification of habitat priorities, underestimation of extinction risks, and the development of conservation strategies that ignore critical local contexts (Alagador and Cerdeira, 2020). Therefore, we must aim to incorproate nonstationarity in ecological models and address its impact on processes occurring on the multiple scales of time, space and organisation relevant to management (Wang et al., 2023). 2025-05-31T23:00:00Z http://hdl.handle.net/10174/41696 Title: IBISurvey: Introduced Bird Interaction Survey – Report 2021-2023 Authors: Pereira, Pedro; Godinho, Carlos; Roque, Inês; Rabaça, João; Lourenço, Rui Abstract: This report summarizes the outcomes of the IBISurvey citizen science project, focusing on reported interactions involving exotic bird species introduced in Europe during the period 2021–2023. 2024-03-31T23:00:00Z