The information about the impacts of thinning on the availability of micro-nutrients, as well as macro-nutrients other than N, P and K, is still scarce. We assessed the changes in the concentrations ...of 12 elements (Al, B, Ca, Cu, Fe, K, Mg, Mn, N, Na, P and Zn) with needle age (current year or 1-year-old) and three early thinning treatments in two of the most widely distributed pines in SW Europe: P. pinaster and P. radiata. Four treatments were setup in triplicate: control (C), light thinning (LT), heavy thinning (HT) and selection thinning of dominant trees (ST), with 0%, 10%, 20% and 20% of total basal area removed, respectively. Needle δ15N varied little with needle age and most thinning treatments in both species, but ST triggered an increase of N in P. pinaster needles. Needle Ca and Na increased with age, but were unaffected by treatment. Foliar K, Zn and Cu decreased with age in both species and increased with ST only in P. pinaster. Jointly considering all treatments, there was no needle age effect on Mn concentration, neither in P. radiata nor in P. pinaster, but in the latter species Mn levels increased with age in the selection thinning plots. There were significant thinning effects on Mn levels in both P. pinaster (ST>C) and P. radiata (HT > LT, ST). Foliar Fe and Al concentration increased with age in both pines; the former increased with ST only in P. pinaster while the latter was affected by thinning only in current year needles and without a clear tendency. Neither age nor treatment effects on needle Mg and B were found, while for P needle age had a significant effect only in P. pinaster.
The crystalline‐to‐vitreous phase transformation of a SiO2 bilayer supported on Ru(0001) was studied by time‐dependent LEED, local XPS, and DFT calculations. The silica bilayer system has parallels ...to 3D silica glass and can be used to understand the mechanism of the disorder transition. DFT simulations show that the formation of a Stone–Wales‐type of defect follows a complex mechanism, where the two layers show decoupled behavior in terms of chemical bond rearrangements. The calculated activation energy of the rate‐determining step for the formation of a Stone—Wales‐type of defect (4.3 eV) agrees with the experimental value. Charge transfer between SiO2 bilayer and Ru(0001) support lowers the activation energy for breaking the Si−O bond compared to the unsupported film. Pre‐exponential factors obtained in UHV and in O2 atmospheres differ significantly, suggesting that the interfacial ORu underneath the SiO2 bilayer plays a role on how the disordering propagates within the film.
Real‐time studies of the crystalline‐to‐vitreous conversion rate of a SiO2 bilayer supported on Ru(0001) reveal an apparent activation energy of 4.2 eV for the process. DFT simulations suggest the formation of a Stone–Wales‐type defect as the starting point for the transformation.
The growing regional and global interests in legume crops for cover cropping and sustainable agriculture has provided new opportunities for growers to incorporate faba bean (Vicia faba L.) into their ...production systems. Much of faba bean's potential, especially in the western United States, is rooted in its high N fixation potential compared with other cultivated legumes. However, faba bean production is currently hindered by existing markets, regional agronomic extension guides, and availability of regionally adapted cultivars. This experiment began the effort to bridge one of the three gaps by evaluating 63 regionally and globally derived plant materials for agronomic and N fixation traits in four environments in California's Central Valley. The experiment observed significant (P ≤ .05) genotype × environment interactions for all faba bean N and agronomic except % of N derived from the atmosphere, harvest index, and 100‐seed weight. Further, we found opportunities to leverage global germplasm to increase or decrease the 100‐seed weight and days to flowering in locally adapted plant materials. Finally, this experiment identified trait‐trait‐associations that provide both opportunities and challenges to improving screening efficiencies (e.g., link between N yield and 100‐seed weight in Chico2019 r = 0.57; P ≤ .001 and in Fresno2020 r = 0.51; P ≤ .001). This work sets a framework for regional faba bean cultivar development work in the western United States.
Core Ideas
Faba bean has high potential for regional sustainable cropping systems.
There are significant genotype × environment interactions for many faba bean agronomic traits.
Global faba bean diversity can be leveraged for regional cultivar improvement.
We discuss the emerging trend that super-Chandrasekhar Type Ia Supernovae (SCSNe) with progenitor mass estimates significantly exceeding ~1.4 M tend to explode in metal-poor environments. While ...Taubenberger et al. noted that some of the SCSNe host galaxies are relatively metal-poor, we focus quantitatively on their locations in the hosts to point out that in three out of four cases, the SCSNe explosions occurred in the outer edge of the disks of their hosts. It is therefore very likely that their progenitors had far lower metallicities than those implied by the metallicity of their hosts' central regions. In two cases (SN 2003fg and SN 2009dc) the explosion sites were outside ~99% of the host's light, and in one case (SN 2006gz) the host's radial metallicity slope indicates that the explosion site is in a metal-poor region. The fourth case (SN 2007if) has the lowest spectroscopically measured SN Ia host metallicity (Childress et al. 2011). It may be possible to explain each of these unusually bright events through some progenitor scenario specific to that case, but a much simpler and straightforward conclusion would be to ascribe the controlling factor to the only physical aspect they have in common--metal-poor environments.
Conjunctival air after neurosurgery Romeu Prieto, J M; García Ortiz, M C; Hernández Martínez, G
Medicina intensiva (English ed.),
10/2018, Letnik:
42, Številka:
7
Journal Article
PDF
