I have performed a two-state mixing analysis between so-called rotational intruder 0+, 2+ and yrast 0+, 2+ states in 112Cd, fitting E2 transition matrix elements to obtain mixing amplitudes and ...matrix elements connecting basis states. Mixing is found to be small for both 0+ and 2+ states. Of two possible solutions, one provides a 0+ mixing amplitude of 0.251– identical to the one derived years ago from 2n transfer data.
Coexistence at the crossroads Boon, Sarah
Science (American Association for the Advancement of Science),
09/2023, Letnik:
381, Številka:
6661
Journal Article
Recenzirano
Ideology meets infrastructure for road ecologists helping flora and fauna live well in the presence of motorways
Challenges including low furfural yield, high energy and fresh water consumption and a high level of pollution have blocked the development of the furfural industry for decades. In this study, a ...seawater-based furfural process integrated with wastewater recycling was proposed. In this process, acetic acid steam and FeCl sub(3) were used as environmentally friendly catalysts instead of mineral acids. In order to provide supporting data for acetic acid steam-catalyzed furfural production, data on the vapor/liquid components of the water + acetic acid system were experimentally determined. In addition, the effects of acetic acid steam, seawater or/and FeCl sub(3) on corncob hydrolysis were systematically investigated. The results indicated that coexistence of three components resulted in a remarkable increase in furfural yield and delignification efficiency. Maximum furfural yields of 72.93% and 79.53% of lignin removal were obtained at 190 degree C in the presence of 60 mM FeCl sub(3) and concentrated seawater (10) in acetic acid steam. Another special focus was put on exploring the feasibility of reutilizing the furfural wastewater as a steam and acetic acid source. The results showed that comparable furfural yield and lignin removal were obtained when furfural wastewater was used instead of pure acetic acid steam. The seawater-based furfural production integrated with wastewater recycling provides a green and environmentally friendly approach to the furfural or other bio-chemicals industry.
1.Ecologists debate the importance of neutral versus niche-based explanations for patterns of species coexistence and whether small-scale data can inform ecological understanding of communities, ...referred to by McNaughton Ecological Monographs, 1983, 53, 291 as 'ecology's cruel dilemma.' Research on phylogenetic relationships, traits and species co-occurrence has attempted to address this topic, with results considerably mixed. 2.We address the hypothesis that plant community assembly is influenced by trait similarity across ecological gradients and this affects mean phylogenetic distance (MPD) of species within sites. We analysed specific leaf area (SLA), maximum plant height and phylogenetic relationships among Serengeti grasses, a system ideally suited to study community assembly because of an ecological gradient in which the dominant plant stress shifts from drought to light competition. 3.Phylogenetic community assembly theory predicts that MPD would be lowest (under-dispersed) at dry sites and greatest (over-dispersed) at sites with higher rainfall. Similarly, theory predicts that low soil nutrient concentrations should filter intolerant species, so that MPD is expected to be under-dispersed at infertile, low-elevation sites and over-dispersed at fertile, higher-elevation sites. However, as gradients of rainfall and soil fertility run counter to one another across the Serengeti, it was unclear how this covariation would influence MPD. 4.Surprisingly, traits showed different evolutionary patterns: SLA displayed convergent evolution while maximum plant height displayed Brownian evolution across the phylogeny. As predicted, statistically under-dispersed assemblages occurred at lower rainfall, infertile sites while statistically over-dispersed assemblages occurred at higher rainfall, fertile sites. However, the pattern across all plots was weak, with most plots showing no statistical pattern of MPD. 5.Multivariate analyses using structural equation modelling, which statistically controlled for covariation among environmental effects, revealed complex direct and indirect effects of environmental variation on MPD, including offsetting direct effects of SLA and maximum plant height due to their different patterns of trait evolution. 6.Synthesis. Spatially counteracting gradients of moisture and soil fertility across the Serengeti, combined with contrasting patterns of trait evolution, obscured the relationship between MPD and any single environmental variable. Our study shows that integrating trait and phylogenetic relationships across ecological gradients yields considerable insight into the ecological mechanisms that determine community composition, but that multivariate techniques may be required to appropriately reveal such patterns.
Understanding the general rules of microbial interactions is central for advancing microbial ecology. Recent studies show that interaction range, interaction strength, and community context determine ...bacterial interactions and the coexistence and evolution of bacteria. We highlight how these factors could contribute to a general understanding of bacterial interactions.
Despite the advances in ecological theory, evidence for the relative importance of the different mechanisms that promote species coexistence is lacking. Some mechanisms depend on the presence of ...interannual fluctuations in the environment combined with interspecific differences in the responses to such fluctuations. Among coexistence mechanisms, niche differentiation and storage effects have received much attention, whereas relative non-linearity (RNL) has been thought to be an unlikely and weak mechanism for multi-species coexistence and remains untested in nature. We quantified the relative contribution of different mechanisms to the coexistence of 19 grassland species by using field-parameterized population models and invasion analysis. Our results showed that 17 out of 19 species had the potential to coexist stably. Species diversity was maintained by RNL and large fluctuation-independent niche differences, i.e., between-species differentiation that is unrelated to interannual variations in environmental factors. Moreover, RNL increased the fitness of species that were less favored by niche differentiation, contributing to their persistence in the community. Storage effect was negligible or destabilizing, making no contribution to stable coexistence. These results, altogether with recent theoretical developments and indirect evidence in published data, call for a reassessment of RNL as a relevant mechanism for multi-species coexistence in nature.
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