| 1. |
- Desprez-Loustau, Marie-Laure, et al.
(författare)
-
From leaf to continent : The multi-scale distribution of an invasive cryptic pathogen complex on oak
- 2018
-
Ingår i: Fungal ecology. - : Elsevier BV. - 1754-5048 .- 1878-0083. ; 36, s. 39-50
-
Tidskriftsartikel (refereegranskat)abstract
- The spatial distribution and niche differentiation of three closely related species (Erysiphe alphitoides, Erysiphe quercicola and Erysiphe hypophylla) causing oak powdery mildew was studied at scales ranging from the European continent, where they are invasive, to a single leaf. While E. alphitoides was dominant at all scales, E. quercicola and E. hypophylla had restricted geographic, stand and leaf distributions. The large-scale distributions were likely explained by climatic factors and species environmental tolerances, with E. quercicola being more frequent in warmer climates and E. hypophylla in colder climates. The extensive sampling and molecular analyses revealed the cryptic invasion of E. quercicola in nine countries from which it had not previously been recorded. The presence of the three species was also strongly affected by host factors, such as oak species and developmental stage. Segregation patterns between Erysiphe species were observed at the leaf scale, between and within leaf surfaces, suggesting competitive effects.
|
|
| 2. |
|
|
| 3. |
- Faticov, Maria, et al.
(författare)
-
Niche differentiation within a cryptic pathogen complex : climatic drivers and hyperparasitism at multiple spatial scales
- 2022
-
Ingår i: Ecography. - : Wiley. - 0906-7590 .- 1600-0587. ; 2022:2
-
Tidskriftsartikel (refereegranskat)abstract
- Pathogens are embedded in multi-trophic food webs, which often include co-occurring cryptic species within the same pathogen complex. Nonetheless, we still lack an understanding of what dimensions of the ecological niche might allow these cryptic species to coexist. We explored the role of climate, host characteristics (tree autumn phenology) and attack by the fungal hyperparasite Ampelomyces (a group of fungi attacking plant pathogens) in defining the niches of three powdery mildew species (Erysiphe alphitoides, E. hypophylla and E. quercicola) within a cryptic pathogen complex on the pedunculate oak Quercus robur at the continental (Europe), national (Sweden and France) and landscape scales (a 5 km2 island in southwestern Finland). Previous studies have shown that climate separated the niches of three powdery mildew species (E. alphitoides, E. hypophylla and E. quercicola) in Europe and two species (E. alphitoides and E. quercicola) in France. In our study, we did not detect a significant relationship between temperature or precipitation and the distribution of E. alphitoides and E. hypophylla present in Sweden, while at the landscape scale, temperature, but not relative humidity, negatively affected disease incidence of E. alphitoides in an exceptionally warm year. Tree variation in autumn phenology did not influence disease incidence of powdery mildew species, and hyperparasite presence did not differ among powdery mildew species at the continental, national and landscape scale. Climate did not affect the distribution of the hyperparasite at the continental scale and at the national scale in Sweden. However, climate affected the hyperparasite distribution in France, with a negative relationship between non-growing season temperature and presence of the hyperparasite. Overall, our findings, in combination with earlier evidence, suggest that climatic factors are more important than species interactions in defining the niches of cryptic species within a pathogen complex on oak.
|
|
| 4. |
- Huang, Shuo, et al.
(författare)
-
Combinatorial design of partial ordered Al-Cr-Mn-Co medium-entropy alloys for room temperature magnetic refrigeration applications
- 2023
-
Ingår i: Applied Physics Letters. - : American Institute of Physics (AIP). - 0003-6951 .- 1077-3118. ; 123:4
-
Tidskriftsartikel (refereegranskat)abstract
- Multi-component alloys have received increasing interest for functional applications in recent years. Here, we explore the magnetocaloric response for Al-Cr-Mn-Co medium-entropy alloys by integrated theoretical and experimental methods. Under the guidance of thermodynamic and ab initio calculations, a dual-phase system with large magnetic moment, i.e., Al50Cr19Mn19Co12, is synthesized, and the structural and magnetocaloric properties are confirmed via characterization. The obtained results indicate that the selected alloy exhibits a co-continuous mixture of a disordered body-centered cubic and an ordered B2 phase. The ab initio and Monte Carlo calculations indicate that the presence of the ordered B2 phase is responsible for the substantial magnetocaloric effect. The magnetization measurements demonstrated that this alloy undergoes a second-order magnetic transition with the Curie temperature of similar to 300 K. The magnetocaloric properties are examined using magnetic entropy change, refrigeration capacity, and adiabatic temperature change. The property-directed strategy explored here is intended to contribute to the study of potential multi-component alloys in magnetocaloric applications.
|
|
