607 research outputs found

    Propagation of nine endemic plant species from Madeira Island (Portugal)

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    Efficient propagation of endangered plant species is a critical factor in successful ecological restoration and conscientious habitat management. Hence, propagation trials of nine endemic plant species of Madeira (Anthyllis lemanniana Lowe, Armeria maderensis Lowe, Cedronella canariensis (L.) Webb & Berthel., Erica maderensis (Benth.) Bornm., Genista tenera (Jacq. ex Murray) Kuntze, Helichrysum melaleucum Rchb. ex Holl, Pericallis aurita (L'Her.) B. Nord., Sideritis candicans Aiton and Teline maderensis Webb & Berthel.) were carried out. Plant propagation requirements and their sexual and vegetative propagation methods were studied. Seed germination success varied between species. Germination rate exceeded 70% in six out of nine species, being lower than 30% in Pericallis aurita, while H. melaleucum seeds did not germinate. Vegetative propagation yielded lower success rates, with three species (Erica maderensis, Genista tenera and Teline maderensis) unable to establish roots, and three species (Helichrysum melaleucum, Pericallis aurita and Sideritis candicans) exceeding 60% of the rooting success. Establishment of the propagation requirements of these species could be regarded an important tool for supporting Madeira’s flora conservation programs.A propagação eficaz de espĂ©cies de plantas ameaçadas pode ser um fator crĂ­tico numa restauração ecolĂłgica de sucesso e numa gestĂŁo consciente de habitats. Por conseguinte, foram realizadas ensaios de propagação de nove espĂ©cies de plantas endĂ©micas da Madeira (Anthyllis lemanniana Lowe, Armeria maderensis Lowe, Cedronella canariensis (L.) Webb & Berthel., Erica maderensis (Benth.) Bornm., Genista tenera (Jacq. Ex Murray) Kuntze, Helichrysum melaleucum Rchb. Ex Holl, Pericallis aurita (L'Her.) B. Nord., Sideritis candicans Aiton e Teline maderensis Webb & Berthel.). Foram analisados os requisitos de propagação destas espĂ©cies atravĂ©s de mĂ©todos de propagação sexual e vegetativa. O sucesso da germinação das sementes variou entre as espĂ©cies. A taxa de germinação foi superior a 70% em seis das nove espĂ©cies, sendo inferior a 30% em Pericallis aurita, e de 0% para H. melaleucum. A propagação vegetativa apresentou taxas de sucesso inferiores, com trĂȘs espĂ©cies (Erica maderensis, Genista tenera e Teline maderensis) incapazes de estabelecer raĂ­zes. Por outro lado, trĂȘs espĂ©cies apresentaram taxas de enraizamento superiores a 60% (Helichrysum melaleucum, Pericallis aurita e Sideritis candicans). O estabelecimento dos requisitos de propagação dessas espĂ©cies pode ser considerado como uma ferramenta importante na conservação da flora da Madeira.nowledgments JosĂ© Manuel Rodrigues and other staff from the Ecological Park of Funchal, SĂłnia Ferraz, Marta Moreira and Filipe Ganança from the ISOPlexis Genebank, and the staff of the Floriculture Centre. We thank Jan J. Slaski of the ISOPlexis Genebank and the Alberta Innovates Technology Futures for reviewing the manuscript.info:eu-repo/semantics/publishedVersio

    Ecology and diversity of Solanum trisectum Dunal from Madeira Island: implications for Its conservation

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    Solanum trisectum Dunal is an endemic Solanaceae of Madeira Island (Portugal), considered critically endangered due to its extreme rarity. Since its discovery this species has shown a narrow distributional range mainly on the northern side of the island, with scattered and small populations and large time gaps between sightings. The present work aimed to understand the underlying ecological underpinnings for this species rarity towards an effort to increase the success of conservation actions. Data on historical locations, environmental conditions field surveys, reinforcement in situ and ex situ germination trials were obtained. The species was found to currently occur only in two wild populations and two reinforcement sites, amounting to twenty-four plants in total. Statistical analysis of these data related wild populations and successful reinforcement sites, separating them from other sites where the reinforcement did not succeed. This suggests that the successful reinforcement sites showed conditions more similar to wild population sites compared to non-successful ones. The data obtained supports the hypothesis that S. trisectum distribution and rarity is determined by species specific habitat needs, i.e., abiotic conditions, which have been for the first time assessed during the present work. Further, this study also reinforces the classification of S. trisectum as a top priority species for conservation.Prospecting, Monitoring and Conservation of Normania triphylla in Madeira (Mohamed bin Zayed Species (project number 13255498)) and Madeira PO 14-20, contract CASBIO (ref M1420-01- 0145-FEDER-000011 ).info:eu-repo/semantics/publishedVersio

    Impairment of the Plasmodium falciparum Erythrocytic Cycle Induced by Angiotensin Peptides

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    Plasmodium falciparum causes the most serious complications of malaria and is a public health problem worldwide with over 2 million deaths each year. The erythrocyte invasion mechanisms by Plasmodium sp. have been well described, however the physiological aspects involving host components in this process are still poorly understood. Here, we provide evidence for the role of renin-angiotensin system (RAS) components in reducing erythrocyte invasion by P. falciparum. Angiotensin II (Ang II) reduced erythrocyte invasion in an enriched schizont culture of P. falciparum in a dose-dependent manner. Using mass spectroscopy, we showed that Ang II was metabolized by erythrocytes to Ang IV and Ang-(1–7). Parasite infection decreased Ang-(1–7) and completely abolished Ang IV formation. Similar to Ang II, Ang-(1–7) decreased the level of infection in an A779 (specific antagonist of Ang-(1–7) receptor, MAS)-sensitive manner. 10−7 M PD123319, an AT2 receptor antagonist, partially reversed the effects of Ang-(1–7) and Ang II. However, 10−6 M losartan, an antagonist of the AT1 receptor, had no effect. Gs protein is a crucial player in the Plasmodium falciparum blood cycle and angiotensin peptides can modulate protein kinase A (PKA) activity; 10−8 M Ang II or 10−8 M Ang-(1–7) inhibited this activity in erythrocytes by 60% and this effect was reversed by 10−7 M A779. 10−6 M dibutyryl-cAMP increased the level of infection and 10−7 M PKA inhibitor decreased the level of infection by 30%. These results indicate that the effect of Ang-(1–7) on P. falciparum blood stage involves a MAS-mediated PKA inhibition. Our results indicate a crucial role for Ang II conversion into Ang-(1–7) in controlling the erythrocytic cycle of the malaria parasite, adding new functions to peptides initially described to be involved in the regulation of vascular tonus

    Impairment of the Plasmodium falciparum Erythrocytic Cycle Induced by Angiotensin Peptides

    Get PDF
    Plasmodium falciparum causes the most serious complications of malaria and is a public health problem worldwide with over 2 million deaths each year. The erythrocyte invasion mechanisms by Plasmodium sp. have been well described, however the physiological aspects involving host components in this process are still poorly understood. Here, we provide evidence for the role of renin-angiotensin system (RAS) components in reducing erythrocyte invasion by P. falciparum. Angiotensin II (Ang II) reduced erythrocyte invasion in an enriched schizont culture of P. falciparum in a dose-dependent manner. Using mass spectroscopy, we showed that Ang II was metabolized by erythrocytes to Ang IV and Ang-(1–7). Parasite infection decreased Ang-(1–7) and completely abolished Ang IV formation. Similar to Ang II, Ang-(1–7) decreased the level of infection in an A779 (specific antagonist of Ang-(1–7) receptor, MAS)-sensitive manner. 10−7 M PD123319, an AT2 receptor antagonist, partially reversed the effects of Ang-(1–7) and Ang II. However, 10−6 M losartan, an antagonist of the AT1 receptor, had no effect. Gs protein is a crucial player in the Plasmodium falciparum blood cycle and angiotensin peptides can modulate protein kinase A (PKA) activity; 10−8 M Ang II or 10−8 M Ang-(1–7) inhibited this activity in erythrocytes by 60% and this effect was reversed by 10−7 M A779. 10−6 M dibutyryl-cAMP increased the level of infection and 10−7 M PKA inhibitor decreased the level of infection by 30%. These results indicate that the effect of Ang-(1–7) on P. falciparum blood stage involves a MAS-mediated PKA inhibition. Our results indicate a crucial role for Ang II conversion into Ang-(1–7) in controlling the erythrocytic cycle of the malaria parasite, adding new functions to peptides initially described to be involved in the regulation of vascular tonus

    Studies of new Higgs boson interactions through nonresonant HH production in the b¯bγγ fnal state in pp collisions at √s = 13 TeV with the ATLAS detector

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    A search for nonresonant Higgs boson pair production in the b ÂŻbγγ fnal state is performed using 140 fb−1 of proton-proton collisions at a centre-of-mass energy of 13 TeV recorded by the ATLAS detector at the CERN Large Hadron Collider. This analysis supersedes and expands upon the previous nonresonant ATLAS results in this fnal state based on the same data sample. The analysis strategy is optimised to probe anomalous values not only of the Higgs (H) boson self-coupling modifer Îșλ but also of the quartic HHV V (V = W, Z) coupling modifer Îș2V . No signifcant excess above the expected background from Standard Model processes is observed. An observed upper limit ”HH < 4.0 is set at 95% confdence level on the Higgs boson pair production cross-section normalised to its Standard Model prediction. The 95% confdence intervals for the coupling modifers are −1.4 < Îșλ < 6.9 and −0.5 < Îș2V < 2.7, assuming all other Higgs boson couplings except the one under study are fxed to the Standard Model predictions. The results are interpreted in the Standard Model efective feld theory and Higgs efective feld theory frameworks in terms of constraints on the couplings of anomalous Higgs boson (self-)interactions

    Measurement of the total cross section and ρ -parameter from elastic scattering in pp collisions at √s=13 TeV with the ATLAS detector

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    Comparison of inclusive and photon-tagged jet suppression in 5.02 TeV Pb+Pb collisions with ATLAS

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    Searches for lepton-flavour-violating decays of the Higgs boson into eτ and Ότ in \sqrt{s} = 13 TeV pp collisions with the ATLAS detector

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    Abstract This paper presents direct searches for lepton flavour violation in Higgs boson decays, H → eτ and H → Ότ, performed using data collected with the ATLAS detector at the LHC. The searches are based on a data sample of proton-proton collisions at a centre-of-mass energy s s \sqrt{s} = 13 TeV, corresponding to an integrated luminosity of 138 fb−1. Leptonic (τ → ℓΜℓΜτ) and hadronic (τ → hadrons Μτ) decays of the τ-lepton are considered. Two background estimation techniques are employed: the MC-template method, based on data-corrected simulation samples, and the Symmetry method, based on exploiting the symmetry between electrons and muons in the Standard Model backgrounds. No significant excess of events is observed and the results are interpreted as upper limits on lepton-flavour-violating branching ratios of the Higgs boson. The observed (expected) upper limits set on the branching ratios at 95% confidence level, B B \mathcal{B} (H → eτ) < 0.20% (0.12%) and B B \mathcal{B} (H → Ότ ) < 0.18% (0.09%), are obtained with the MC-template method from a simultaneous measurement of potential H → eτ and H → Ότ signals. The best-fit branching ratio difference, B B \mathcal{B} (H → Ότ) → B B \mathcal{B} (H → eτ), measured with the Symmetry method in the channel where the τ-lepton decays to leptons, is (0.25 ± 0.10)%, compatible with a value of zero within 2.5σ

    Measurement of the H → γ γ and H → ZZ∗ → 4 cross-sections in pp collisions at √s = 13.6 TeV with the ATLAS detector

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    The inclusive Higgs boson production cross section is measured in the di-photon and the Z Z∗ → 4 decay channels using 31.4 and 29.0 fb−1 of pp collision data respectively, collected with the ATLAS detector at a centre of-mass energy of √s = 13.6 TeV. To reduce the model dependence, the measurement in each channel is restricted to a particle-level phase space that closely matches the chan nel’s detector-level kinematic selection, and it is corrected for detector effects. These measured fiducial cross-sections are σfid,Îł Îł = 76+14 −13 fb, and σfid,4 = 2.80 ± 0.74 fb, in agreement with the corresponding Standard Model predic tions of 67.6±3.7 fb and 3.67±0.19 fb. Assuming Standard Model acceptances and branching fractions for the two chan nels, the fiducial measurements are extrapolated to the full phase space yielding total cross-sections of σ (pp → H) = 67+12 −11 pb and 46±12 pb at 13.6 TeV from the di-photon and Z Z∗ → 4 measurements respectively. The two measure ments are combined into a total cross-section measurement of σ (pp → H) = 58.2±8.7 pb, to be compared with the Stan dard Model prediction of σ (pp → H)SM = 59.9 ± 2.6 p
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