Quasiparticle interfacial level alignment of highly hybridized frontier levels: H2_2O on TiO2_2(110)

Knowledge of the frontier levels' alignment prior to photo-irradiation is necessary to achieve a complete quantitative description of H$_2$O photocatalysis on TiO$_2$(110). Although H$_2$O on rutile TiO$_2$(110) has been thoroughly studied both experimentally and theoretically, a quantitative value for the energy of the highest H$_2$O occupied levels is still lacking. For experiment, this is due to the H$_2$O levels being obscured by hybridization with TiO$_2$(110) levels in the difference spectra obtained via ultraviolet photoemission spectroscopy (UPS). For theory, this is due to inherent difficulties in properly describing many-body effects at the H$_2$O-TiO$_2$(110) interface. Using the projected density of states (DOS) from state-of-the-art quasiparticle (QP) $G_0W_0$, we disentangle the adsorbate and surface contributions to the complex UPS spectra of H$_2$O on TiO$_2$(110). We perform this separation as a function of H$_2$O coverage and dissociation on stoichiometric and reduced surfaces. Due to hybridization with the TiO$_2$(110) surface, the H$_2$O 3a$_1$ and 1b$_1$ levels are broadened into several peaks between 5 and 1 eV below the TiO$_2$(110) valence band maximum (VBM). These peaks have both intermolecular and interfacial bonding and antibonding character. We find the highest occupied levels of H$_2$O adsorbed intact and dissociated on stoichiometric TiO$_2$(110) are 1.1 and 0.9 eV below the VBM. We also find a similar energy of 1.1 eV for the highest occupied levels of H$_2$O when adsorbed dissociatively on a bridging O vacancy of the reduced surface. In both cases, these energies are significantly higher (by 0.6 to 2.6 eV) than those estimated from UPS difference spectra, which are inconclusive in this energy region. Finally, we apply self-consistent QP$GW$ (scQP$GW$1) to obtain the ionization potential of the H$_2$O-TiO$_2$(110) interface.Comment: 12 pages, 12 figures, 1 tabl

Towards a multisensor station for automated biodiversity monitoring

Rapid changes of the biosphere observed in recent years are caused by both small and large scale drivers, like shifts in temperature, transformations in land-use, or changes in the energy budget of systems. While the latter processes are easily quantifiable, documentation of the loss of biodiversity and community structure is more difficult. Changes in organismal abundance and diversity are barely documented. Censuses of species are usually fragmentary and inferred by often spatially, temporally and ecologically unsatisfactory simple species lists for individual study sites. Thus, detrimental global processes and their drivers often remain unrevealed. A major impediment to monitoring species diversity is the lack of human taxonomic expertise that is implicitly required for large-scale and fine-grained assessments. Another is the large amount of personnel and associated costs needed to cover large scales, or the inaccessibility of remote but nonetheless affected areas. To overcome these limitations we propose a network of Automated Multisensor stations for Monitoring of species Diversity (AMMODs) to pave the way for a new generation of biodiversity assessment centers. This network combines cutting-edge technologies with biodiversity informatics and expert systems that conserve expert knowledge. Each AMMOD station combines autonomous samplers for insects, pollen and spores, audio recorders for vocalizing animals, sensors for volatile organic compounds emitted by plants (pVOCs) and camera traps for mammals and small invertebrates. AMMODs are largely self-containing and have the ability to pre-process data (e.g. for noise filtering) prior to transmission to receiver stations for storage, integration and analyses. Installation on sites that are difficult to access require a sophisticated and challenging system design with optimum balance between power requirements, bandwidth for data transmission, required service, and operation under all environmental conditions for years. An important prerequisite for automated species identification are databases of DNA barcodes, animal sounds, for pVOCs, and images used as training data for automated species identification. AMMOD stations thus become a key component to advance the field of biodiversity monitoring for research and policy by delivering biodiversity data at an unprecedented spatial and temporal resolution. (C) 2022 Published by Elsevier GmbH on behalf of Gesellschaft fur Okologie

Current Status and Future Prospects of Next-Generation Data Management and Analytical Decision Support Tools for Enhancing Genetic Gains in Crops

Agricultural disciplines are becoming data intensive and the agricultural research data generation technologies are becoming sophisticated and high throughput. On the one hand, high-throughput genotyping is generating petabytes of data; on the other hand, high-throughput phenotyping platforms are also generating data of similar magnitude. Under modern integrated crop breeding, scientists are working together by integrating genomic and phenomic data sets of huge data volumes on a routine basis. To manage such huge research data sets and use them appropriately in decision making, Data Management Analysis & Decision Support Tools (DMASTs) are a prerequisite. DMASTs are required for a range of operations including generating the correct breeding experiments, maintaining pedigrees, managing phenotypic data, storing and retrieving high-throughput genotypic data, performing analytics, including trial analysis, spatial adjustments, identifications of MTAs, predicting Genomic Breeding Values (GEBVs), and various selection indices. DMASTs are also a prerequisite for understanding trait dynamics, gene action, interactions, biology, GxE, and various other factors contributing to crop improvement programs by integrating data generated from various science streams. These tools have simplified scientists’ lives and empowered them in terms of data storage, data retrieval, data analytics, data visualization, and sharing with other researchers and collaborators. This chapter focuses on availability, uses, and gaps in present-day DMASTs

ESTs in Plants: Where Are We Heading?

Expressed sequence tags (ESTs) are the most important resources for transcriptome exploration. Next-generation sequencing technologies have been generating gigabytes of genetic codes representing genes, partial and whole genomes most of which are EST datasets. Niche of EST in plants for breeding, regulation of gene expression through miRNA studies, and their application for adapting to climatic changes are discussed. Some of the recent tools for analysis of EST exclusive to plants are listed out. Systems biology though in its infancy in plants has influenced EST mapping for unraveling gene regulatory circuits, which is illustrated with a few significant examples. This review throws a glance at the evolving role of ESTs in plants

Accounting for the ‘network’ in the Natura 2000 network: A response to Hochkirch et al. 2013

Engler JO, Cord AF, Dieker P, Waegele JW, Rödder D. Accounting for the ‘network’ in the Natura 2000 network: A response to Hochkirch et al. 2013. Submitted.Worldwide, we are experiencing an unprecedented, accelerated loss of biodiversity triggered by a bundle of anthropogenic threats such as habitat destruction, environmental pollution and climate change. Despite all efforts of the European biodiversity conservation policy, initiated 20 years ago by the Habitats Directive that provided the legal basis for establishing the Natura 2000 network, the goal to halt the decline of biodiversity in Europe by 2010 has been missed. Hochkirch et al. (2013, Conserv. Lett. 6: 462-467) identified four major shortcomings of the current implementation of the directive concerning prioritization of the annexes, conservation plans, survey systems and financial resources. However they did not account for the intended network character of the Natura 2000 sites, an aspect of highest relevance. This response letter deals with this shortcoming as it is the prerequisite, over any other strategies, ensuring a Natura 2020 network being worth its name

Existence of an Electrochemically Inert CO Population on Cu Electrodes in Alkaline pH

Surface-adsorbed CO is generally considered a reactive on-pathway intermediate in the aqueous electrochemical reduction of CO₂ on Cu electrodes. Though CO can bind to a variety of adsorption sites (e.g., atop or bridge), spectroscopic studies of the Cu/electrolyte contact have mostly been concerned with atop-bound CO. Using surface-selective infrared (IR) spectroscopy, we have investigated the reactivities and coverages of atop- and bridge-bound CO on a polycrystalline Cu electrode in contact with alkaline electrolytes. We show here that (1) a fraction of atop-bound CO converts to bridge-bonded CO when the total CO coverage drops below the saturation coverage and (2) unlike atop-bound CO, bridge-bonded CO is an unreactive species that is not reduced at a potential of −1.75 V vs SHE. Our results suggest that bridge-bonded CO is not an on-pathway intermediate in CO reduction. Using density functional theory (DFT) calculations, we further reveal that the activation barrier for the hydrogenation of bridge-bonded CO to surface-adsorbed formyl on Cu(100) is higher than that of the reduction of atop-bound CO, in qualitative agreement with our experimental findings. The possible modulation of the catalytic properties of the interface by the electrochemically inert bridge-bonded CO population should be considered in future studies involving CO₂ or CO reduction on Cu under alkaline conditions

Spectroscopic Observation of Reversible Surface Reconstruction of Copper Electrodes under CO₂ Reduction

The ability of copper to catalyze the electrochemical reduction of CO₂ has been shown to greatly depend on its nanoscale surface morphology. While previous studies found evidence of irreversible changes of copper nanoparticle and thin film electrodes following electrolysis, we present here the first observation of the <i>reversible</i> reconstruction of electrocatalytic copper surfaces induced by the adsorbed CO intermediate. Using attenuated total internal reflection infrared and surface-enhanced Raman spectroscopies, the reversible formation of nanoscale metal clusters on the electrode is revealed by the appearance of a new CO absorption band characteristic of CO bound to undercoordinated copper atoms and by the strong enhancement of the surface-enhanced Raman effect. Our study shows that the morphology of the catalytic copper surface is not static but dynamically adapts with changing reaction conditions