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- Blanco-Gavaldà, Carme, et al.
(författare)
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Repeatedly Northwards and Upwards: Southern African Grasslands Fuel the Colonization of the African Sky Islands in Helichrysum (Compositae)
- 2023
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Ingår i: Plants. ; 12:2213, s. 1-24
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Tidskriftsartikel (refereegranskat)abstract
- The Afromontane and Afroalpine areas constitute some of the main biodiversity hotspots of Africa. They are particularly rich in plant endemics, but the biogeographic origins and evolutionary processes leading to this outstanding diversity are poorly understood. We performed phylogenomic and biogeographic analyses of one of the most species-rich plant genera in these mountains, Helichrysum (Compositae-Gnaphalieae). Most previous studies have focused on Afroalpine elements of Eurasian origin, and the southern African origin of Helichrysum provides an interesting counterexample. We obtained a comprehensive nuclear dataset from 304 species ( 50% of the genus) using target-enrichment with the Compositae1061 probe set. Summary-coalescent and concatenation approaches combined with paralog recovery yielded congruent, well-resolved phylogenies. Ancestral range estimations revealed that Helichrysum originated in arid southern Africa, whereas the southern African grasslands were the source of most lineages that dispersed within and outside Africa. Colonization of the tropical Afromontane and Afroalpine areas occurred repeatedly throughout the Miocene–Pliocene. This timing coincides with mountain uplift and the onset of glacial cycles, which together may have facilitated both speciation and intermountain gene flow, contributing to the evolution of the Afroalpine flora.
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| 2. |
- Casals, Nuria Fuertes, et al.
(författare)
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Influence of annealing oxide structure and composition on pickling of the duplex stainless steel 1.4462
- 2011
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Ingår i: 7th European Stainless Steel Conference: Science and Market, Proceedings. - : Associazione Italiana di Metallurgia. - 9788885298842
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Konferensbidrag (refereegranskat)abstract
- In this work, correlation between the oxide formation and pickling behaviour of a conventional duplex material - 1.4462 is reported. The materials investigated are the duplex grade 1.4462 and two single phase alloys with compositions corresponding to the respective phases of the duplex material. Annealing was conducted at 1070 °C for 8 minutes. Topography and composition of the oxide layer were analysed with GDOES, FIB, XRD, SEM-EDS and CLSM. The ferritic steel formed a thick chromium-enriched oxide with a silica-rich sublayer. On the austenitic steel, ironenriched nodules were observed in the centre of the grains, together with oxide ridges on the top of the grain boundaries. The oxide on the duplex grade differed depending on the phase; nodule formation was observed on the austenitic grains while a more homogenous oxide formed on the ferritic grains. Pickling was performed in a mixed nitric/hydrofluoric acid bath. The fastest removal was observed for the austenitic sample, followed by the duplex and the ferritic samples. The oxide on the austenitic sample spalled from the surface while the oxide on the ferritic grade was removed by dissolution rather than by spallation. A mixed behaviour was observed on the duplex grade where some zones pickled faster than others.
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| 3. |
- Martínez-Sánchez, Noelia, et al.
(författare)
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Hypothalamic AMPK-ER Stress-JNK1 Axis Mediates the Central Actions of Thyroid Hormones on Energy Balance
- 2017
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Ingår i: Cell Metabolism. - Cambridge, MA, United States : Cell Press. - 1550-4131 .- 1932-7420. ; 26:1, s. 212-229.e12
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Tidskriftsartikel (refereegranskat)abstract
- Thyroid hormones (THs) act in the brain to modulate energy balance. We show that central triiodothyronine (T3) regulates de novo lipogenesis in liver and lipid oxidation in brown adipose tissue (BAT) through the parasympathetic (PSNS) and sympathetic nervous system (SNS), respectively. Central T3 promotes hepatic lipogenesis with parallel stimulation of the thermogenic program in BAT. The action of T3 depends on AMP-activated protein kinase (AMPK)-induced regulation of two signaling pathways in the ventromedial nucleus of the hypothalamus (VMH): decreased ceramide-induced endoplasmic reticulum (ER) stress, which promotes BAT thermogenesis, and increased c-Jun N-terminal kinase (JNK) activation, which controls hepatic lipid metabolism. Of note, ablation of AMPKα1 in steroidogenic factor 1 (SF1) neurons of the VMH fully recapitulated the effect of central T3, pointing to this population in mediating the effect of central THs on metabolism. Overall, these findings uncover the underlying pathways through which central T3 modulates peripheral metabolism.
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