| 1. |
- Jung, Christian, et al.
(författare)
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A comparison of very old patients admitted to intensive care unit after acute versus elective surgery or intervention
- 2019
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Ingår i: Journal of critical care. - : W B SAUNDERS CO-ELSEVIER INC. - 0883-9441 .- 1557-8615. ; 52, s. 141-148
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Tidskriftsartikel (refereegranskat)abstract
- Background: We aimed to evaluate differences in outcome between patients admitted to intensive care unit (ICU) after elective versus acute surgery in a multinational cohort of very old patients (80 years; VIP). Predictors of mortality, with special emphasis on frailty, were assessed.Methods: In total, 5063 VIPs were induded in this analysis, 922 were admitted after elective surgery or intervention, 4141 acutely, with 402 after acute surgery. Differences were calculated using Mann-Whitney-U test and Wilcoxon test. Univariate and multivariable logistic regression were used to assess associations with mortality.Results: Compared patients admitted after acute surgery, patients admitted after elective surgery suffered less often from frailty as defined as CFS (28% vs 46%; p < 0.001), evidenced lower SOFA scores (4 +/- 5 vs 7 +/- 7; p < 0.001). Presence of frailty (CFS >4) was associated with significantly increased mortality both in elective surgery patients (7% vs 12%; p = 0.01), in acute surgery (7% vs 12%; p = 0.02).Conclusions: VIPs admitted to ICU after elective surgery evidenced favorable outcome over patients after acute surgery even after correction for relevant confounders. Frailty might be used to guide clinicians in risk stratification in both patients admitted after elective and acute surgery.
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| 2. |
- Almeida, Erika, et al.
(författare)
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Antipredator responses of two anurans towards native and exotic predators
- 2011
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Ingår i: Amphibia-Reptilia. - 0173-5373 .- 1568-5381. ; 32:3, s. 341-350
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Tidskriftsartikel (refereegranskat)abstract
- When faced with the risk of predation, tadpoles of many amphibian species are known to modify their phenotype. In this work we studied the effect of an exotic species, the red swamp crayfish (Procambarus clarkii), on the phenotype of two species of amphibians with different reproduction habitats: the Iberian painted frog, Discoglossus galganoi, that normally reproduces in temporary water bodies and the common toad, Bufo bufo, that reproduces in permanent water bodies. The responses were compared with the ones shown in the presence of a native predator, dragonfly (Aeshnidae) larvae. Behaviour, growth and morphology of tadpoles were monitored in a factorial experiment with five treatments. Our results showed that only the permanent habitat species altered its behaviour and life-history traits in the presence of P. clarkii; however, this was mediated by chemical cues from consumed conspecifics. Antipredator responses of B. bufo towards the exotic crayfish were similar to the ones towards the native predator, while D. galganoi responded to the dragonfly larvae but not to P. clarkii. This may be the result of infrequent colonization events of temporary habitats by the crayfish. Therefore, the consequences of the introduction of P. clarkii might be more serious for D. galganoi and other species living in temporary habitats. Species breeding in permanent habitats, more prone to having generalized antipredator responses, may be relatively protected against this exotic crayfish although the effectiveness of these responses still needs to be tested.
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| 3. |
- Barredo, José I., et al.
(författare)
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Mapping and assessment of forest ecosystems and their services : Applications and guidance for decision making in the framework of MAES
- 2015
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this report is to illustrate by means of a series of case studies the implementation of mapping and assessment of forest ecosystem services in different contexts and geographical levels. Methodological aspects, data issues, approaches, limitations, gaps and further steps for improvement are analysed for providing good practices and decision making guidance. The EU initiative on Mappingand Assessment of Ecosystems and their Services (MAES), with the support of all Member States, contributes to improve the knowledge on ecosystem services. MAES is one of the building-block initiatives supporting the EU Biodiversity Strategy to 2020.
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| 4. |
- Carreira, Bruno M., et al.
(författare)
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Can heat waves change the trophic role of the world's most invasive crayfish? : Diet shifts in Procambarus clarkii
- 2017
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Ingår i: PLOS ONE. - : PUBLIC LIBRARY SCIENCE. - 1932-6203. ; 12:9
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Tidskriftsartikel (refereegranskat)abstract
- In the Mediterranean basin, the globally increasing temperatures are expected to be accompanied by longer heat waves. Commonly assumed to benefit cold-limited invasive alien species, these climatic changes may also change their feeding preferences, especially in the case of omnivorous ectotherms. We investigated heat wave effects on diet choice, growth and energy reserves in the invasive red swamp crayfish, Procambarus clarkii. In laboratory experiments, we fed juvenile and adult crayfish on animal, plant or mixed diets and exposed them to a short or a long heat wave. We then measured crayfish survival, growth, body reserves and Fulton's condition index. Diet choices of the crayfish maintained on the mixed diet were estimated using stable isotopes (C-13 and N-15). The results suggest a decreased efficiency of carnivorous diets at higher temperatures, as juveniles fed on the animal diet were unable to maintain high growth rates in the long heat wave; and a decreased efficiency of herbivorous diets at lower temperatures, as juveniles in the cold accumulated less body reserves when fed on the plant diet. Heat wave treatments increased the assimilation of plant material, especially in juveniles, allowing them to sustain high growth rates in the long heat wave. Contrary to our expectations, crayfish performance decreased in the long heat wave, suggesting that Mediterranean summer heat waves may have negative effects on P. clarkii and that they are unlikely to boost its populations in this region. Although uncertain, it is possible that the greater assimilation of the plant diet resulted from changes in crayfish feeding preferences, raising the hypotheses that i) heat waves may change the predominant impacts of this keystone species and ii) that by altering species' trophic niches, climate change may alter the main impacts of invasive alien species.
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| 5. |
- Carreira, Bruno M., et al.
(författare)
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Heat waves trigger swift changes in the diet and life-history of a freshwater snail
- 2020
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Ingår i: Hydrobiologia. - : Springer Science and Business Media LLC. - 0018-8158 .- 1573-5117. ; 847:4, s. 999-1011
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Tidskriftsartikel (refereegranskat)abstract
- Extreme climatic events, such as heat waves, may induce changes in nutrient acquisition by omnivorous ectotherms. Likely modulated by the intensity, frequency and duration of these events, dietary shifts during heat waves may threaten the stability of freshwaters. We investigated the effects of heat wave duration on diet assimilation and life-history traits of the freshwater gastropod Radix balthica. We compared the magnitude of the effects of a short (1 week) and a long heat wave (7 weeks) on the assimilation of animal- and plant-based diets, measuring performance in terms of growth rate and reproduction. We hypothesized that heat waves should increase the proportion of plant material assimilated on the mixed diet and change the performance of snails on the animal and plant-based diets. Both heat waves increased the assimilation of plant material on the mixed diet and growth rate, with minor negative effects on reproduction. However, responses were disproportional to heat wave duration, as the short heat wave elicited swift and relatively stronger responses. Our findings showcase the role of phenotypic plasticity in aiding ectotherms to cope with increased thermal stress and acclimate. Temporarily changing the strength of trophic interactions, heat waves may alter community dynamics in freshwater habitats.
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| 6. |
- Matos, Rui, et al.
(författare)
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Improved design of tubular wind tower foundations using steel micropiles
- 2016
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Ingår i: Structure and Infrastructure Engineering. - : Informa UK Limited. - 1573-2479 .- 1744-8980. ; 12:9, s. 1038-1050
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Tidskriftsartikel (refereegranskat)abstract
- The constant increase in the wind power production leads to the need of higher wind towers, which brings up some questions regarding the effectiveness of tubular towers and respective foundations. This work focuses on the comparative structural design, life cycle behaviour and costs of onshore concrete shallow foundations for tubular wind towers (WT) when steel micropiles are used to improve resistance of the soil–structure interface (hybrid foundation). Typical wind loading for Turbine Class II and moderate seismicity (.25 g peak ground acceleration) is used to design and analyse 18 WT foundation case studies. This allows the comparison between shallow and hybrid foundations designed for three different hub heights and respective turbine rated power (80 m/2 MW, 100 m/3.6 MW and 150 m/5 MW) and for three different tubular tower solutions (steel, concrete and hybrid steel–concrete). The possible benefits of the solution using steel grouted micropiles are discussed in terms of potential environmental and economic impacts using life cycle analysis. The use of micropiles reveals to be an interesting solution to improve common shallow WT foundations since it allows the reduction of the dimensions of the foundation leading to significant environmental and cost benefits.
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| 7. |
- Nunes, Ana L., et al.
(författare)
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Do anuran larvae respond behaviourally to chemical cues from an invasive crayfish predator? : A community-wide study
- 2013
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Ingår i: Oecologia. - : Springer Science and Business Media LLC. - 0029-8549 .- 1432-1939. ; 171:1, s. 115-127
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Tidskriftsartikel (refereegranskat)abstract
- Antipredator behaviour is an important fitness component in most animals. A co-evolutionary history between predator and prey is important for prey to respond adaptively to predation threats. When non-native predator species invade new areas, native prey may not recognise them or may lack effective antipredator defences. However, responses to novel predators can be facilitated by chemical cues from the predators' diet. The red swamp crayfish Procambarus clarkii is a widespread invasive predator in the Southwest of the Iberian Peninsula, where it preys upon native anuran tadpoles. In a laboratory experiment we studied behavioural antipredator defences (alterations in activity level and spatial avoidance of predator) of nine anurans in response to P. clarkii chemical cues, and compared them with the defences towards a native predator, the larval dragonfly Aeshna sp. To investigate how chemical cues from consumed conspecifics shape the responses, we raised tadpoles with either a tadpole-fed or starved crayfish, or dragonfly larva, or in the absence of a predator. Five species significantly altered their behaviour in the presence of crayfish, and this was largely mediated by chemical cues from consumed conspecifics. In the presence of dragonflies, most species exhibited behavioural defences and often these did not require the presence of cues from predation events. Responding to cues from consumed conspecifics seems to be a critical factor in facilitating certain behavioural responses to novel exotic predators. This finding can be useful for predicting antipredator responses to invasive predators and help directing conservation efforts to the species at highest risk.
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| 8. |
- Nunes, Ana L., et al.
(författare)
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Morphological and life-history responses of anurans to predation by an invasive crayfish : an integrative approach
- 2014
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Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 4:8, s. 1491-1503
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Tidskriftsartikel (refereegranskat)abstract
- Predator-induced phenotypic plasticity has been widely documented in response to native predators, but studies examining the extent to which prey can respond to exotic invasive predators are scarce. As native prey often do not share a long evolutionary history with invasive predators, they may lack defenses against them. This can lead to population declines and even extinctions, making exotic predators a serious threat to biodiversity. Here, in a community-wide study, we examined the morphological and life-history responses of anuran larvae reared with the invasive red swamp crayfish, Procambarus clarkii, feeding on conspecific tadpoles. We reared tadpoles of nine species until metamorphosis and examined responses in terms of larval morphology, growth, and development, as well as their degree of phenotypic integration. These responses were compared with the ones developed in the presence of a native predator, the larval dragonfly Aeshna sp., also feeding on tadpoles. Eight of the nine species altered their morphology or life history when reared with the fed dragonfly, but only four when reared with the fed crayfish, suggesting among-species variation in the ability to respond to a novel predator. While morphological defenses were generally similar across species (deeper tails) and almost exclusively elicited in the presence of the fed dragonfly, life-history responses were very variable and commonly elicited in the presence of the invasive crayfish. Phenotypes induced in the presence of dragonfly were more integrated than in crayfish presence. The lack of response to the presence of the fed crayfish in five of the study species suggests higher risk of local extinction and ultimately reduced diversity of the invaded amphibian communities. Understanding how native prey species vary in their responses to invasive predators is important in predicting the impacts caused by newly established predator-prey interactions following biological invasions.
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| 9. |
- Nunes, Ana L., et al.
(författare)
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Nonlethal injury caused by an invasive alien predator and its consequences for an anuran tadpole
- 2010
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Ingår i: Basic and Applied Ecology. - : Elsevier BV. - 1439-1791 .- 1618-0089. ; 11:7, s. 645-654
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Tidskriftsartikel (refereegranskat)abstract
- Nonlethal tail injury resulting from unsuccessful predation attempts is common in anuran larvae and can potentially induce significant fitness costs in terms of survival and growth. We tested the hypotheses that the alien red swamp crayfish, Procambarus clarkii, is an important inducer of tail injury in tadpoles of the Iberian spadefoot toad, Pelobates cultripes, and that tail damage can have important consequences for the tadpoles' life history and morphology. This was investigated by first estimating frequencies of caudal injury in P. cult ripes tadpoles in temporary ponds, with and without crayfish. Secondly, we performed a laboratory experiment in which four levels of tail injury frequency were combined with two levels of food availability. The frequency of tadpoles with damaged tails was higher in ponds with crayfish and the presence of this predator was the strongest predictor of tail injury frequency in a pond. Induced tail loss decreased larval survivorship and affected tail morphology, with injured tadpoles developing deeper tail muscles and shallower tail fins. The magnitude of these effects depended on injury frequency, as well as on food availability. The results suggest that P. clarkii is inflicting tail injuries at much higher levels than those occurring before its introduction; these injuries affect tadpole morphology and may induce delayed fitness costs.
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| 10. |
- Nunes, Ana L., et al.
(författare)
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Rapid evolution of constitutive and inducible defenses against an invasive predator
- 2014
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Ingår i: Ecology. - : Wiley. - 0012-9658 .- 1939-9170. ; 95:6, s. 1520-1530
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Tidskriftsartikel (refereegranskat)abstract
- Invasive alien predators can impose strong selection on native prey populations and induce rapid evolutionary change in the invaded communities. However, studies on evolutionary responses to invasive predators are often complicated by the lack of replicate populations differing in coexistence time with the predator, which would allow the determination of how prey traits change during the invasion. The red swamp crayfish Procambarus clarkii has invaded many freshwater areas worldwide, with negative impacts for native fauna. Here, we examined how coexistence time shapes antipredator responses of the Iberian waterfrog (Pelophylax perezi) to the invasive crayfish by raising tadpoles from five populations differing in historical exposure to P. clarkii (30 years, 20 years, or no coexistence). Tadpoles from non-invaded populations responded to the presence of P. clarkii with behavioral plasticity (reduced activity), whereas long-term invaded populations showed canalized antipredator behavior (constant low activity level). Tadpoles from one of the long-term invaded populations responded to the crayfish with inducible morphological defenses (deeper tails), reflecting the use of both constitutive and inducible antipredator defenses against the exotic predator by this population. Our results suggest that, while naive P. perezi populations responded behaviorally to P. clarkii, the strong predation pressure imposed by the crayfish has induced the evolution of qualitatively different antipredator defenses in populations with longer coexistence time. These responses suggest that strong selection by invasive predators may drive rapid evolutionary change in invaded communities. Examining responses of prey species to biological invasions using multiple populations will help us better forecast the impact of invasive predators in natural communities.
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