1. |
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2. |
- Ferreira, Daniela, et al.
(författare)
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Transcription and regulation of the hydrogenase(s) accessory genes, hypFCDEAB, in the cyanobacterium Lyngbya majuscula CCAP 1446/4
- 2007
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Ingår i: Archives of Microbiology. - : Springer Science and Business Media LLC. - 0302-8933 .- 1432-072X. ; 188:6, s. 609-617
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Tidskriftsartikel (refereegranskat)abstract
- Lyngbya majuscula CCAP 1446/4 is a filamentous cyanobacterium possessing both an uptake and a bi-directional hydrogenase. The presence of a single copy of the hyp operon in the cyanobacterial genomes suggests that these accessory genes might be responsible for the maturation of both hydrogenases. We investigated the concomitant transcription of hypFCDEAB with the hydrogenases structural genes-hup and hox. RT-PCRs performed with L. majuscula cells grown under different physiological conditions showed a substantial decrease in the relative amount of hupL transcript under non-N-2-fixing conditions. In contrast, no significant differences were observed for the transcript levels of hypFCDEAB in all conditions tested, while minor fluctuations could be discerned for hoxH. Previously, it was demonstrated that the transcriptional regulators NtcA and LexA interact with the promoter regions of hup and hox, respectively, and that putative binding sites for both proteins are present in the hyp promoter of L. majuscula. Therefore, a putative involvement of NtcA and LexA in the regulation of the hyp transcription was investigated. Electrophoretic mobility shift assays resulted in NtcA or LexA-bound retarded fragments, suggesting the involvement of these proteins in the transcriptional regulation of hypFCDEAB.
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3. |
- Ferreira, Mafalda S., et al.
(författare)
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The evolution of white-tailed jackrabbit camouflage
- 2023
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 379:6638, s. 1238-1242
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Tidskriftsartikel (refereegranskat)abstract
- The genetic basis of adaptive traits has rarely been used to predict future vulnerability of populations to climate change. We show that light versus dark seasonal pelage in white-tailed jackrabbits (Lepus townsendii) tracks snow cover and is primarily determined by genetic variation at endothelin receptor type B (EDNRB), corin serine peptidase (CORIN), and agouti signaling protein (ASIP). Winter color variation was associated with deeply divergent alleles at these genes, reflecting selection on both ancestral and introgressed variation. Forecasted reductions in snow cover are likely to induce widespread camouflage mismatch. However, simulated populations with variation for darker winter pelage are predicted to adapt rapidly, providing a trait-based genetic framework to facilitate evolutionary rescue. These discoveries demonstrate how the genetic basis of climate change adaptation can inform conservation.
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4. |
- Ferreira, Mafalda S, et al.
(författare)
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The Legacy of Recurrent Introgression during the Radiation of Hares
- 2020
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Ingår i: Systematic Biology. - : Oxford University Press (OUP). - 1063-5157 .- 1076-836X. ; 70:3, s. 593-607
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Tidskriftsartikel (refereegranskat)abstract
- Hybridization may often be an important source of adaptive variation, but the extent and long-term impacts of introgression have seldom been evaluated in the phylogenetic context of a radiation. Hares (Lepus) represent a widespread mammalian radiation of 32 extant species characterized by striking ecological adaptations and recurrent admixture. To understand the relevance of introgressive hybridization during the diversification of Lepus, we analyzed whole exome sequences (61.7 Mb) from 15 species of hares (1–4 individuals per species), spanning the global distribution of the genus, and two outgroups. We used a coalescent framework to infer species relationships and divergence times, despite extensive genealogical discordance. We found high levels of allele sharing among species and show that this reflects extensive incomplete lineage sorting and temporally layered hybridization. Our results revealed recurrent introgression at all stages along the Lepus radiation, including recent gene flow between extant species since the last glacial maximum but also pervasive ancient introgression occurring since near the origin of the hare lineages. We show that ancient hybridization between northern hemisphere species has resulted in shared variation of potential adaptive relevance to highly seasonal environments, including genes involved in circadian rhythm regulation, pigmentation, and thermoregulation. Our results illustrate how the genetic legacy of ancestral hybridization may persist across a radiation, leaving a long-lasting signature of shared genetic variation that may contribute to adaptation.
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5. |
- Ferreira, Mafalda S., et al.
(författare)
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The transcriptional landscape of seasonal coat colour moult in the snowshoe hare
- 2017
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Ingår i: Molecular Ecology. - : Wiley. - 0962-1083 .- 1365-294X. ; 26:16, s. 4173-4185
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Tidskriftsartikel (refereegranskat)abstract
- Seasonal coat colour change is an important adaptation to seasonally changing environments but the evolution of this and other circannual traits remains poorly understood. In this study, we use gene expression to understand seasonal coat colour moulting in wild snowshoe hares (Lepus americanus). We used hair colour to follow the progression of the moult, simultaneously sampling skin from three moulting stages in hares collected during the peak of the spring moult from white winter to brown summer pelage. Using RNA sequencing, we tested whether patterns of expression were consistent with predictions based on the established phases of the hair growth cycle. We found functionally consistent clustering across skin types, with 766 genes differentially expressed between moult stages. “White” pelage showed more differentially expressed genes that were upregulated relative to other skin types, involved in the transition between late telogen (quiescent stage) and the onset of anagen (proliferative stage). Skin samples from transitional “intermediate” and “brown” pelage were transcriptionally similar and resembled the regressive transition to catagen (regressive stage). We also detected differential expression of several key circadian clock and pigmentation genes, providing important means to dissect the bases of alternate seasonal colour morphs. Our results reveal that pelage colour is a useful biomarker for seasonal change but that there is a consistent lag between the main gene expression waves and change in visible coat colour. These experiments establish that developmental sampling from natural populations of nonmodel organisms can provide a crucial resource to dissect the genetic basis and evolution of complex seasonally changing traits.
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6. |
- Marques, João P., et al.
(författare)
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Mountain hare transcriptome and diagnostic markers as resources to monitor hybridization with European hares
- 2017
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Ingår i: Scientific Data. - : Springer Science and Business Media LLC. - 2052-4463. ; 4:1
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Tidskriftsartikel (refereegranskat)abstract
- We report the first mountain hare (Lepus timidus) transcriptome, produced by de novo assembly of RNA-sequencing reads. Data were obtained from eight specimens sampled in two localities, Alps and Ireland. The mountain hare tends to be replaced by the invading European hare (Lepus europaeus) in their numerous contact zones where the species hybridize, which affects their gene pool to a yet unquantified degree. We characterize and annotate the mountain hare transcriptome, detect polymorphism in the two analysed populations and use previously published data on the European hare (three specimens, representing the European lineage of the species) to identify 4 672 putative diagnostic sites between the species. A subset of 85 random independent SNPs was successfully validated using PCR and Sanger sequencing. These valuable genomic resources can be used to design tools to assess population status and monitor hybridization between species.
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7. |
- Muscarella, Robert, et al.
(författare)
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The global abundance of tree palms
- 2020
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Ingår i: Global Ecology and Biogeography. - : Wiley. - 1466-822X .- 1466-8238. ; 29:9, s. 1495-1514
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Tidskriftsartikel (refereegranskat)abstract
- AimPalms are an iconic, diverse and often abundant component of tropical ecosystems that provide many ecosystem services. Being monocots, tree palms are evolutionarily, morphologically and physiologically distinct from other trees, and these differences have important consequences for ecosystem services (e.g., carbon sequestration and storage) and in terms of responses to climate change. We quantified global patterns of tree palm relative abundance to help improve understanding of tropical forests and reduce uncertainty about these ecosystems under climate change.LocationTropical and subtropical moist forests.Time periodCurrent.Major taxa studiedPalms (Arecaceae).MethodsWe assembled a pantropical dataset of 2,548 forest plots (covering 1,191 ha) and quantified tree palm (i.e., ≥10 cm diameter at breast height) abundance relative to co‐occurring non‐palm trees. We compared the relative abundance of tree palms across biogeographical realms and tested for associations with palaeoclimate stability, current climate, edaphic conditions and metrics of forest structure.ResultsOn average, the relative abundance of tree palms was more than five times larger between Neotropical locations and other biogeographical realms. Tree palms were absent in most locations outside the Neotropics but present in >80% of Neotropical locations. The relative abundance of tree palms was more strongly associated with local conditions (e.g., higher mean annual precipitation, lower soil fertility, shallower water table and lower plot mean wood density) than metrics of long‐term climate stability. Life‐form diversity also influenced the patterns; palm assemblages outside the Neotropics comprise many non‐tree (e.g., climbing) palms. Finally, we show that tree palms can influence estimates of above‐ground biomass, but the magnitude and direction of the effect require additional work.ConclusionsTree palms are not only quintessentially tropical, but they are also overwhelmingly Neotropical. Future work to understand the contributions of tree palms to biomass estimates and carbon cycling will be particularly crucial in Neotropical forests.
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8. |
- Nguyen, Thanh N, et al.
(författare)
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Global Impact of the COVID-19 Pandemic on Stroke Volumes and Cerebrovascular Events: A 1-Year Follow-up.
- 2023
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Ingår i: Neurology. - 1526-632X. ; 100:4
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Tidskriftsartikel (refereegranskat)abstract
- Declines in stroke admission, IV thrombolysis (IVT), and mechanical thrombectomy volumes were reported during the first wave of the COVID-19 pandemic. There is a paucity of data on the longer-term effect of the pandemic on stroke volumes over the course of a year and through the second wave of the pandemic. We sought to measure the effect of the COVID-19 pandemic on the volumes of stroke admissions, intracranial hemorrhage (ICH), IVT, and mechanical thrombectomy over a 1-year period at the onset of the pandemic (March 1, 2020, to February 28, 2021) compared with the immediately preceding year (March 1, 2019, to February 29, 2020).We conducted a longitudinal retrospective study across 6 continents, 56 countries, and 275 stroke centers. We collected volume data for COVID-19 admissions and 4 stroke metrics: ischemic stroke admissions, ICH admissions, IVT treatments, and mechanical thrombectomy procedures. Diagnoses were identified by their ICD-10 codes or classifications in stroke databases.There were 148,895 stroke admissions in the 1 year immediately before compared with 138,453 admissions during the 1-year pandemic, representing a 7% decline (95% CI [95% CI 7.1-6.9]; p < 0.0001). ICH volumes declined from 29,585 to 28,156 (4.8% [5.1-4.6]; p < 0.0001) and IVT volume from 24,584 to 23,077 (6.1% [6.4-5.8]; p < 0.0001). Larger declines were observed at high-volume compared with low-volume centers (all p < 0.0001). There was no significant change in mechanical thrombectomy volumes (0.7% [0.6-0.9]; p = 0.49). Stroke was diagnosed in 1.3% [1.31-1.38] of 406,792 COVID-19 hospitalizations. SARS-CoV-2 infection was present in 2.9% ([2.82-2.97], 5,656/195,539) of all stroke hospitalizations.There was a global decline and shift to lower-volume centers of stroke admission volumes, ICH volumes, and IVT volumes during the 1st year of the COVID-19 pandemic compared with the prior year. Mechanical thrombectomy volumes were preserved. These results suggest preservation in the stroke care of higher severity of disease through the first pandemic year.This study is registered under NCT04934020.
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9. |
- Pinto, Luís Valença, et al.
(författare)
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Assessment of NBS Impact on Pluvial Flood Regulation Within Urban Areas : A Case Study in Coimbra, Portugal
- 2022
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Ingår i: Nature-Based Solutions for Flood Mitigation. - Cham : Springer Science and Business Media Deutschland GmbH. - 9783030775056 ; , s. 289-312
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Bokkapitel (refereegranskat)abstract
- The majority of the world population is living in urban areas. As cities expand, soil sealing increases the vulnerability of urban areas to pluvial floods, and the consequent impacts on social and economic domains. Flood mitigation typically relies on grey infrastructures, but the implementation of Nature-Based Solutions (NBS) can be critical to cope with increasing flood hazard driven by urbanization and climate change. By mimicking natural hydrological processes, NBS enhance water retention, infiltration and evapotranspiration through greening, leading to lower runoff and flood hazard. The effectiveness of NBS on flood mitigation is affected by several factors including the type of NBS and the biophysical characteristics of the area. Nevertheless, a relatively limited number of studies have monitored the impact of NBS, and thus the lack of knowledge is still a barrier to the widespread implementation of this approach. This chapter assesses the impact of a Green Infrastructure (GI) located in Coimbra (Portugal), which performs as a NBS for runoff management and flood hazard mitigation. The study applies the widely used Curve Number method to estimate runoff within the Quinta de São Jerónimo study site, driven by rainfall events of 2-, 5-, 10- and 20-years recurrence, based on Intensity–Duration–Frequency precipitation curves. The results show that the implemented NBS can retain runoff produced by 20-years flood, decreasing the flood peak and flood hazard in downstream urban areas. This efficiency is achieved by combining blue, green and grey elements, and proved useful to enhance urban resilience. Furthermore, the green and blue elements of the NBS provide additional ecosystem services, including environmental, social and economic benefits (co-benefits), relevant for human well-being in urban areas.
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10. |
- Pinto, Luís Valença, et al.
(författare)
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Ecosystem services and well-being dimensions related to urban green spaces - A systematic review
- 2022
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Ingår i: Sustainable cities and society. - : Elsevier BV. - 2210-6707. ; 85
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Forskningsöversikt (refereegranskat)abstract
- Urban green spaces (UGS) supply several ecosystem services (ES) key to human wellbeing. In this article, we conducted a systematic review focused on identifying UGS's ES and wellbeing dimensions. From the 3626 articles screened, 218 were used in this review. Most studies were conducted in Europe, China, the United States of America (USA) and South Africa. Among all UGS, parks and gardens were the most investigated, with less of a focus on urban trees, forests, coastal mangroves, golf courses, roadside vegetation, and brownfields/unmanaged urban greenery. Cultural ES were the most studied, although it is well known that UGS also supply many provisioning and regulating ES. Health (mental and physical) and good social relations were the most investigated wellbeing dimensions, and food security received the least attention. Regarding the methodologies used to investigate the UGS contribution to human wellbeing, surveys, indicators, and surveys combined with statistical methods were the most common. Only a few works focusing on spatial modelling were validated, which is critical to ensure the reliability of the spatial models applied to UGS ES studies. Overall, this work identified the research gaps and future perspectives in ES and wellbeing dimensions provided by UGS, key to improving further research.
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11. |
- Salbego, Rafaela Stocker, et al.
(författare)
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Influence of psychometric and sleep quality features on painful mechanical sensitivity and pain modulation in patients with temporomandibular disorders
- 2024
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Ingår i: Clinical Oral Investigations. - : Springer Nature. - 1432-6981 .- 1436-3771. ; 28:6
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Tidskriftsartikel (refereegranskat)abstract
- Investigating the collective impact of psychometric properties and sleep quality on pain sensitivity in temporomandibular disorder (TMD) patients could improve clinical management strategies. Objective Assessing whether combined psychometric properties and sleep quality impact painful mechanical sensitivity and pain modulation in TMD patients. Materials and methods A cross-sectional study using secondary data analysis of 77 TMD patients and 101 controls. All participants completed questionnaires characterizing their psychometric profile (anxiety, depression, stress and catastrophizing) and sleep quality, alongside psychophysical tests for painful mechanical sensory (mechanical pain threshold (MPT), pressure pain threshold (PPT), and wind-up ratio (WUR)) and conditioned pain modulation (CPM). Participants were grouped into "High distress" or "Low distress" categories based on psychometric properties and sleep quality using hierarchical cluster and k-means analyses. Multiple linear regression evaluated the influence of TMD, age, and the distress cluster on MPT, WUR, PPT, and CPM in masseter and thenar muscles. Differences were statistically significant when p < 0.05. Results The presence of TMD was the strongest predictor of mechanical painful sensitivity in the trigeminal region (MPT[F(3,174) = 51.902;p < .001;R-2 = .463]; TMD presence (beta = -.682) / PPT[F(3,174) = 15.573;p < .001;R-2 = .198] TMD presence (beta = -.452), and extra-trigeminal (MPT[F(3,174) = 35.897;p < .001;R-2 = .382] TMD (beta = -.647) / CPM [F(3,174) = 4.106;p < .05;R2 = .050] TMD presence (beta = .197). Furthermore, neither the high distress group nor the low distress group were able to significantly influence the variation of the values of any of the psychophysical variables evaluated (p > .05). Conclusions There is not a significant influence of impairment clusters based on psychological variables and sleep quality on painful mechanical sensitivity and pain modulation, regardless of the presence of TMD. Clinical relevance This outcome suggests that psychosocial factors and sleep quality may not play a decisive role in the sensory-discriminative aspect of pain, particularly concerning painful TMD.
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12. |
- Silventoinen, Karri, et al.
(författare)
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Genetic and environmental variation in educational attainment : an individual-based analysis of 28 twin cohorts
- 2020
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Ingår i: Scientific Reports. - : Springer Nature. - 2045-2322. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the heritability of educational attainment and how it differed between birth cohorts and cultural–geographic regions. A classical twin design was applied to pooled data from 28 cohorts representing 16 countries and including 193,518 twins with information on educational attainment at 25 years of age or older. Genetic factors explained the major part of individual differences in educational attainment (heritability: a2 = 0.43; 0.41–0.44), but also environmental variation shared by co-twins was substantial (c2 = 0.31; 0.30–0.33). The proportions of educational variation explained by genetic and shared environmental factors did not differ between Europe, North America and Australia, and East Asia. When restricted to twins 30 years or older to confirm finalized education, the heritability was higher in the older cohorts born in 1900–1949 (a2 = 0.44; 0.41–0.46) than in the later cohorts born in 1950–1989 (a2 = 0.38; 0.36–0.40), with a corresponding lower influence of common environmental factors (c2 = 0.31; 0.29–0.33 and c2 = 0.34; 0.32–0.36, respectively). In conclusion, both genetic and environmental factors shared by co-twins have an important influence on individual differences in educational attainment. The effect of genetic factors on educational attainment has decreased from the cohorts born before to those born after the 1950s.
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13. |
- Tavares, Julia, et al.
(författare)
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Basin-wide variation in tree hydraulic safety margins predicts the carbon balance of Amazon forests
- 2023
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Ingår i: Nature. - : Springer Nature. - 0028-0836 .- 1476-4687. ; 617:7959, s. 111-117
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Tidskriftsartikel (refereegranskat)abstract
- Tropical forests face increasing climate risk(1,2), yet our ability to predict their response to climate change is limited by poor understanding of their resistance to water stress. Although xylem embolism resistance thresholds (for example, ?(50)) and hydraulic safety margins (for example, HSM50) are important predictors of drought-induced mortality risk(3-5), little is known about how these vary across Earth's largest tropical forest. Here, we present a pan-Amazon, fully standardized hydraulic traits dataset and use it to assess regional variation in drought sensitivity and hydraulic trait ability to predict species distributions and long-term forest biomass accumulation. Parameters ?(50) and HSM50 vary markedly across the Amazon and are related to average long-term rainfall characteristics. Both ?(50) and HSM50 influence the biogeographical distribution of Amazon tree species. However, HSM50 was the only significant predictor of observed decadal-scale changes in forest biomass. Old-growth forests with wide HSM50 are gaining more biomass than are low HSM(50 )forests. We propose that this may be associated with a growth-mortality trade-off whereby trees in forests consisting of fast-growing species take greater hydraulic risks and face greater mortality risk. Moreover, in regions of more pronounced climatic change, we find evidence that forests are losing biomass, suggesting that species in these regions may be operating beyond their hydraulic limits. Continued climate change is likely to further reduce HSM50 in the Amazon(6,7), with strong implications for the Amazon carbon sink.
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14. |
- Albano, Michele, et al.
(författare)
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Quality of Service on the Arrowhead Framework
- 2017
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Ingår i: 2017 IEEE 13th International Workshop on Factory Communication Systems (WFCS). - Piscataway, NJ : Institute of Electrical and Electronics Engineers (IEEE). - 9781509057887
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Konferensbidrag (refereegranskat)abstract
- Quality of Service (QoS) is an important enabler for communication in industrial environments. The Arrowhead Framework was created to support local cloud functionalities for automation applications by means of a Service Oriented Architecture. To this aim, the framework offers a number of services that ease application development, among them the QoSSetup and the Monitor services, the first used to verify and configure QoS in the local cloud, and the second for online monitoring of QoS. This paper describes how the QoSSetup and Monitor services are provided in a Arrowhead-compliant System of Systems, detailing both the principles and algorithms employed, and how the services are implemented. Experimental results are provided, from a demonstrator built over a real-time Ethernet network.
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15. |
- Anjos, Rita, et al.
(författare)
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Macular Ganglion Cell Layer and Peripapillary Retinal Nerve Fibre Layer Thickness in Patients with Unilateral Posterior Cerebral Artery Ischaemic Lesion : An Optical Coherence Tomography Study
- 2016
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Ingår i: Neuro-ophthalmology (Aeolus Press. 1980). - : Taylor & Francis. - 0165-8107 .- 1744-506X. ; 40:1, s. 8-15
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this study is to evaluate the macular ganglion cell layer (GCL) and peripapillary retinal nerve fibre layer (RNFL) thickness in patients with unilateral posterior cerebral artery (PCA) ischaemic lesions using spectral-domain optical coherence tomography (SD-OCT). A prospective, case-control study of patients with unilateral PCA lesion was conducted in the neuro-ophthalmology clinic of Centro Hospitalar Lisboa Central. Macular and peripapillary SD-OCT scans were performed in both eyes of each patient. Twelve patients with PCA lesions (stroke group) and 12 healthy normal controls were included in this study. Peripapillary RNFL comparison between both eyes of the same subject in the stroke group found a thinning in the superior-temporal (p = 0.008) and inferior-temporal (p = 0.023) sectors of the ipsilateral eye and nasal sector (p = 0.003) of the contralateral eye. Macular GCL thickness comparison showed a reduction temporally in the ipsilateral eye (p = 0.004) and nasally in the contralateral eye (p = 0.002). Peripapillary RNFL thickness was significantly reduced in both eyes of patients with PCA compared with controls, affecting all sectors in the contralateral eye and predominantly temporal sectors in the ipsilateral eye. A statistically significant decrease in macular GCL thickness was found in both hemiretinas of both eyes of stroke patients when compared with controls (p < 0.05). This study shows that TRD may play a role in the physiopathology of lesions of the posterior visual pathway.
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16. |
- Bergamini, Mariana Lobo, et al.
(författare)
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Presence of langerhans cells, regulatory T cells (Treg) and mast cells in asymptomatic apical periodontitis
- 2020
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Ingår i: BRAZILIAN ORAL RESEARCH. - : FapUNIFESP (SciELO). - 1807-3107 .- 1806-8324. ; 34
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Tidskriftsartikel (refereegranskat)abstract
- Asymptomatic Apical Periodontitis is essentially an inflammatory disease of microbial aetiology. Association and function of the cell components involved, or specific inductive factors and growth mediators associated with development, maintenance and resolution of the periapical lesions are still unknown. The objective of this study was to evaluate the concentration of Regulatory T cells (FoxP3+; Treg), Langerhans cells (CD1a+; LC) and mast cells in asymptomatic apical periodontitis. 73 cases were selected: 30 periapical granulomas, 29 radicular cysts and 14 residual cysts. All groups were submitted to morphological analysis for classification of inflammatory infiltrate and thickness of the epithelial lining as well as to immunohistochemical analysis for detection of LC and Treg cells. Toluidine blue staining was used for detecting mast cells. Analysis showed higher mean numbers of LC (8.2 cells/0.2mm(2)), and Treg cells in radicular cysts (5.910 cells/0.2mm(2)). As for mast cells, it was found that radicular cysts had a higher mean number of these cells compared to other periapical lesions (12.68 cells/0.2mm(2)). The association between thickness of the epithelial lining and inflammatory cells showed that the presence of hypertrophic epithelium in radicular cysts presented higher density of LC. The number of LC and Treg cells play an important role in the control of the inflammatory micro-environment in periapical granulomas and radicular cysts, respectively. The presence of mast cells in radicular cysts may be associated with progression of the lesion. Knowledge regarding the inflammatory cell profile is therefore essential for a better understanding of the pathogenesis of asymptomatic periapical periodontitis.
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17. |
- Bustin, Stephen A., et al.
(författare)
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The need for transparency and good practices in the qPCR literature
- 2013
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Ingår i: Nature Methods. - : Springer Science and Business Media LLC. - 1548-7091 .- 1548-7105. ; 10:11, s. 1063-1067
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Two surveys of over 1,700 publications whose authors use quantitative real-time PCR (qPCR) reveal a lack of transparent and comprehensive reporting of essential technical information. Reporting standards are significantly improved in publications that cite the Minimum Information for Publication of Quantitative Real-Time PCR Experiments (MIQE) guidelines, although such publications are still vastly outnumbered by those that do not.
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18. |
- Crespo, Alejandro J., et al.
(författare)
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On the state-of-the-art of CFD simulations for wave energy converters within the open-source numerical framework of DualSPHysics
- 2023
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Ingår i: Proceedings of the 15th European Wave and Tidal Energy Conference, Bilbao, 3-7 September 2023. - : European Wave and Tidal Energy Conference.
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Konferensbidrag (refereegranskat)abstract
- There are currently several types of devices capable of harnessing wave energy, exploiting a broad variety of physical transformation processes. These devices – known as Wave Energy Converters (WECs) – are developed to maximize their power output. However, there are still uncertainties about their response and survivability to loads induced by adverse environmental conditions, with a consequent increase of the Levelized Cost of Energy (LCOE), which prevents in fact their commercial diffusion. As evidenced by a large body of research, marine renewable energy devices need to have more robust design practices. To address this issue, we propose the CFD-based DualSPHysics toolbox as a support in the design stages. DualSPHysics is high-fidelity software inherently suited to numerically address most challenges posed by multiphysics simulations, which are required to reliably predict WEC response in situations well beyond operational conditions. It should be noted that WECs, generally, may be connected to the seabed and comprise mechanical systems named Power Take-Offs (PTO) used to convert the energy from waves into electricity or other usable energies. To reproduce these features, DualSPHysics benefits from coupling with the multiphysics library Project Chrono and the dynamic mooring model Moordyn+. In this work, the augmented DualSPHysics framework is utilised to simulate a range of very different types of WECs with a variety of elements, such as catenary connections, taut mooring lines, or linear and nonlinear PTO actuators. Version 5.2 of the open-source licensed code was recently released, making the numerical framework publicly available as one unit. This work aims to provide a numerical review of past applications, and to demonstrate how the same open-source code is able to simulate very different technologies.Specifically, this paper proposes routine modeling and validation procedures using the SPH-based solver DualSPHysics applied to five different WEC types: i) a moored point absorber (PA); ii) an oscillating wave surge converter (OWSC); iii) a floating OWSC (so called FOSWEC); iv) a wave energy hyperbaric converter (WEHC); and v) a multi-body attenuator (so called Multi-float M4). For each device listed above, we provide validation proof against physical model data for various components of the floater(s) and PTO related quantities, performed under specific sea conditions that aim to challenge their survivability. Within the scope of this research, we present the WEC response with respect to the degrees of freedom that really matter for each of the floatings due to hydrodynamic interactions (i.e., heave, surge, and pitch), along with quantities more intimately connected to the anchoring systems (e.g., line tension) or the mechanical apparatus (e.g., end-stopper force). The quality of the results, the discussion built upon them and the demonstrated solver exploitability to a wide range of WECs show that one software model can run all cases using the exact same methodology, which is of great value for the marine energy R&D community. Finally, we discuss future research objectives, which include the implementation of automation to apply open control systems and possible applications to subsets of WEC farm arrays and other floating energy harnessing devices.
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19. |
- Davids, Peter R., et al.
(författare)
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Multi-, inter-, and transdisciplinary approaches to nature-based flood risk management
- 2024
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Ingår i: Current Opinion in Environmental Science and Health. - : Elsevier BV. - 2468-5844. ; 38
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Forskningsöversikt (refereegranskat)abstract
- Nature-based solutions (NBS) can act as a valuable complement to conventional ‘grey’ infrastructure for stormwater management (e.g. dams and dikes) in reducing flood risks as these ‘green’ solutions are perceived to be more flexible and multifunctional. However, to achieve effective NBS, a multi-actor approach in developing appropriate measures for specific sites is required as NBS occupy more space than ‘grey’ infrastructure and often overlap with private land. NBS also necessitate a multidisciplinary approach, to maximise environmental, social, and economic benefits. Thus, a transdisciplinary approach is needed for the effective implementation of NBS. Viewing NBS as a boundary concept, focusing on the common ground for different disciplines and actors, can facilitate communication and provide a first step towards effective flood risk mitigation.
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20. |
- de Amorim Lima, Nayane Maria, et al.
(författare)
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Light-Emitting Porphyrin Derivative Obtained from a Subproduct of the Cashew Nut Shell Liquid : A Promising Material for OLED Applications
- 2019
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Ingår i: Materials. - : MDPI. - 1996-1944. ; 12:7
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Tidskriftsartikel (refereegranskat)abstract
- In this work, the meso-tetra[4-(2-(3-n-pentadecylphenoxy)ethoxy]phenylporphyrin (H2P), obtained from the cashew nut shell liquid (CNSL), and its zinc (ZnP) and copper (CuP) metallic complexes, were applied as emitting layers in organic light emitting diodes (OLEDs). These compounds were characterized via optical and electrochemical analysis and the electroluminescent properties of the device have been studied. We performed a cyclic voltammetry analysis to determine the Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) energy levels for the porphyrins, in order to select the proper materials to assemble the device. H2P and ZnP presented fluorescence emission band in the red region, from 601 nm to 718 nm. Moreover, we verified that the introduction of bulky substituents hinders the - stacking, favoring the emission in the film. In addition, the strongest emitter, ZnP, presented a threshold voltage of 4 V and the maximum irradiance of 10 W cm(-2) with a current density (J) of 15 mA cm(-2) at 10 V. The CuP complex showed to be a favorable material for the design of OLEDs in the infrared. These results suggest that the porphyrins derived from a renewable source, such as CNSL, is a promising material to be used in organic optoelectronic devices such as OLEDs.
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21. |
- de Melo Barros Junior, Paulo Roberto, et al.
(författare)
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Multi-fractal detrended cross-correlation heatmaps for time series analysis
- 2022
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Ingår i: Scientific Reports. - : NATURE PORTFOLIO. - 2045-2322. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Complex systems in biology, climatology, medicine, and economy hold emergent properties such as non-linearity, adaptation, and self-organization. These emergent attributes can derive from large-scale relationships, connections, and interactive behavior despite not being apparent from their isolated components. It is possible to better comprehend complex systems by analyzing cross-correlations between time series. However, the accumulation of non-linear processes induces multiscale structures, therefore, a spectrum of power-law exponents (the fractal dimension) and distinct cyclical patterns. We propose the Multifractal detrended cross-correlation heatmaps (MF-DCCHM) based on the DCCA cross-correlation coefficients with sliding boxes, a systematic approach capable of mapping the relationships between fluctuations of signals on different scales and regimes. The MF-DCCHM uses the integrated series of magnitudes, sliding boxes with sizes of up to 5% of the entire series, and an average of DCCA coefficients on top of the heatmaps for the local analysis. The heatmaps have shown the same cyclical frequencies from the spectral analysis across different multifractal regimes. Our dataset is composed of sales and inventory from the Brazilian automotive sector and macroeconomic descriptors, namely the Gross Domestic Product (GDP) per capita, Nominal Exchange Rate (NER), and the Nominal Interest Rate (NIR) from the Central Bank of Brazil. Our results indicate cross-correlated patterns that can be directly compared with the power-law spectra for multiple regimes. We have also identified cyclical patterns of high intensities that coincide with the Brazilian presidential elections. The MF-DCCHM uncovers non-explicit cyclic patterns, quantifies the relations of two non-stationary signals (noise effect removed), and has outstanding potential for mapping cross-regime patterns in multiple domains.
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22. |
- Dias-Ferreira, João, 1986-
(författare)
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Bio-Inspired Self-Organising Architecture for Cyber-Physical Manufacturing Systems
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The refinement in consumer's requirements and the fast paced development of socio-technical systems, are promoting, increasingly globalized markets with a high demand for fast time-to-market, sustainable, high quality and highly customized, or even personalized, low priced products. This new reality is forcing companies to change and adapt their business strategies, so that they can quickly and efficiently engage in short-window business opportunities. A critical enabler of the companies' ability to tackle these opportunities is the shopfloor and its ability to cope with change. In this sense, a number of modern manufacturing paradigms emerged, that propose a relaxation of the strictness of the control chains and new modular system designs, that tolerate a controlled and regulated unpredictability of the system behaviour, and simultaneously foster the system's autonomy, robustness, adaptability, plug-ability, evolution and self-organisation.From a structural and dynamic perspective such solutions become, therefore, close to biological systems. In fact, biological systems and their characteristics are a common analogy to express the high level design principles, of modern production paradigms. However, despite this common source of inspiration, the application of bio-inspired concepts, is often lost due to design and implementation choices, or is simply limited to heuristic approaches, that solve specific hard optimization problems.In this dissertation, a bio-inspired reference architecture for production systems, focused on highly dynamic environments, denominated "BIO-inspired Self-Organising ARchitecture for Manufacturing systems" (BIOSOARM), is presented. BIOSOARM was developed under the umbrella of Evolvable Production Systems (EPS) and aims to strictly adhere to bio-inspired principles. For this purpose, both shopfloor components and product parts are individualized and extended into the virtual environment, as fully decoupled autonomous entities, where they interact, following bio-inspired patterns, and cooperate towards the emergence of a self-organising behaviour, that leads to the emergence of the necessary production flows and consequently of the desired products. BIOSOARM, therefore, introduces a fundamentally novel approach to production, that decouples the system's operation from eventual changes, uncertainty or even critical failures, while simultaneously ensures the performance levels and simplifies the deployment, reconfiguration/adaptation and evolution procedures, enabling companies to cope with the new highly dynamic and challenging environments.
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23. |
- Eng, Frida, 1977-
(författare)
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Non-Uniform Sampling in Statistical Signal Processing
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Non-uniform sampling comes natural in many applications, due to for example imperfect sensors, mismatched clocks or event-triggered phenomena. Examples can be found in automotive industry and data communication as well as medicine and astronomy. Yet, the literature on statistical signal processing to a large extent focuses on algorithms and analysis for uniformly, or regularly, sampled data. This work focuses on Fourier analysis, system identification and decimation of non-uniformly sampled data.In non-uniform sampling (NUS), signal amplitude and time stamps are delivered in pairs. Several methods to compute an approximate Fourier transform (AFT) have appeared in literature, and their posterior properties in terms of alias suppression and leakage have been addressed. In this thesis, the sampling times are assumed to be generated by a stochastic process, and the main idea is to use information about the stochastic sampling process to calculate a priori properties of approximate frequency transforms. These results are also used to give insight in frequency domain system identification and help with analysis of down-sampling algorithms.The main result gives the prior distribution of several AFTs expressed in terms of the true Fourier transform and variants of the characteristic function of the sampling time distribution. The result extends leakage and alias suppression with bias and variance terms due to NUS. Based on this, decimation of non-uniformly sampled signals, using continuous-time anti-alias filters, is analyzed. The decimation is based on interpolation in different domains, and interpolation in the convolution integral proves particularly useful. The same idea is also used to investigate how stochastic unmeasurable sampling jitter noise affects the result of system identification. The result is a modification of known approaches to mitigate the bias and variance increase caused by the sampling jitter noise.The bottom line is that, when non-uniform sampling is present, the approximate frequency transform, identified transfer function and anti-alias filter are all biased to what is expected from classical theory on uniform sampling. This work gives tools to analyze and correct for this bias.
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24. |
- Erjefält, Jonas S., et al.
(författare)
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Diffuse alveolar damage patterns reflect the immunological and molecular heterogeneity in fatal COVID-19
- 2022
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Ingår i: EBioMedicine. - : Elsevier BV. - 2352-3964. ; 83
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Tidskriftsartikel (refereegranskat)abstract
- Background: Severe COVID-19 lung disease exhibits a high degree of spatial and temporal heterogeneity, with different histological features coexisting within a single individual. It is important to capture the disease complexity to support patient management and treatment strategies. We provide spatially decoded analyses on the immunopathology of diffuse alveolar damage (DAD) patterns and factors that modulate immune and structural changes in fatal COVID-19. Methods: We spatially quantified the immune and structural cells in exudative, intermediate, and advanced DAD through multiplex immunohistochemistry in autopsy lung tissue of 18 COVID-19 patients. Cytokine profiling, viral, bacteria, and fungi detection, and transcriptome analyses were performed. Findings: Spatial DAD progression was associated with expansion of immune cells, macrophages, CD8+ T cells, fibroblasts, and (lymph)angiogenesis. Viral load correlated positively with exudative DAD and negatively with disease/hospital length. In all cases, enteric bacteria were isolated, and Candida parapsilosis in eight cases. Cytokines correlated mainly with macrophages and CD8+T cells. Pro-coagulation and acute repair were enriched pathways in exudative DAD whereas intermediate/advanced DAD had a molecular profile of elevated humoral and innate immune responses and extracellular matrix production. Interpretation: Unraveling the spatial and molecular immunopathology of COVID-19 cases exposes the responses to SARS-CoV-2-induced exudative DAD and subsequent immune-modulatory and remodeling changes in proliferative/advanced DAD that occur side-by-side together with secondary infections in the lungs. These complex features have important implications for disease management and the development of novel treatments. Funding: CNPq, Bill and Melinda Gates Foundation, HC-Convida, FAPESP, Regeneron Pharmaceuticals, and the Swedish Heart & Lung Foundation.
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25. |
- Ferreira, Carla S. S., et al.
(författare)
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Conclusions
- 2022
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Ingår i: Nature-Based Solutions for Flood Mitigation. - Cham : Springer. - 9783030775049 - 9783030775056 ; , s. 507-513
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Bokkapitel (refereegranskat)abstract
- Mitigating and adapting to increasing flood risk driven by climate change and growing urbanization is still a challenge for humanity. Over the last decades, the Nature Based Solutions (NBS) approach has received increasing interest from governments, academia and society, but its implementation is still in its infancy. This volume presented an up-to-date compilation about the current knowledge on NBS regarding their potential to mitigate several types of floods recorded in different environments, the associated advantages and limitations, and the barriers affecting their wider implementation. This concluding chapter provides a synthesis of the main messages of the chapters included in this volume, and it highlights the relevant aspects that must be considered for an effective and broader application of NBS. In this regard, particular attention is given to the need to maximize their multifunctionality and to consider the transdisciplinary nature of the NBS approach.
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