3D hierarchical heterostructure NiFe LDH@NiCoP/NF electrodes are prepared successfully on nickel foam with special interface engineering and synergistic effects. This research finds that the ...as‐prepared NiFe LDH@NiCoP/NF electrodes have a more sophisticated inner structure and intensive interface than a simple physical mixture. The NiFe LDH@NiCoP/NF electrodes require an overpotential as low as 120 and 220 mV to deliver 10 mA cm−2 for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in 1 m KOH, respectively. Tafel and electrochemical impedance spectroscopy further reveal a favorable kinetic during electrolysis. Specifically, the NiFe LDH@NiCoP/NF electrodes are simultaneously used as cathode and anode for overall water splitting, which requires a cell voltage of 1.57 V at 10 mA cm−2. Furthermore, the synergistic effect of the heterostructure improves the structural stability and promotes the generation of active phases during HER and OER, resulting in excellent stability over 100 h of continuous operation. Moreover, the strategy and interface engineering of the introduced heterostructure can also be used to prepare other bifunctional and cost‐efficient electrocatalysts for various applications.
As‐synthesized NiFe layered double hydroxide (LDH)@NiCoP/Nickel foam (NF) electrodes exhibit excellent activity and stability for both hydrogen evolution reaction and oxygen evolution reaction owing to special interface engineering and synergistic effects. It is further used for overall water splitting with a cell voltage of 1.57 V and an outstanding stability for 100 h.
Besides their use in fuel cells for energy conversion through the oxygen reduction reaction (ORR), carbon‐based metal‐free catalysts have also been demonstrated to be promising alternatives to ...noble‐metal/metal oxide catalysts for the oxygen evolution reaction (OER) in metal–air batteries for energy storage and for the splitting of water to produce hydrogen fuels through the hydrogen evolution reaction (HER). This Review focuses on recent progress in the development of carbon‐based metal‐free catalysts for the OER and HER, along with challenges and perspectives in the emerging field of metal‐free electrocatalysis.
Free agents: Carbon‐based metal‐free catalysts have been intensively researched as alternatives to noble‐metal/metal oxide catalysts for the oxygen evolution reaction (OER) in metal–air batteries and for the splitting of water through the hydrogen evolution reaction (HER). This Review gives an overview of recent developments in this area, with a focus on the OER and HER.
Evolution of Ecological Niche Breadth Sexton, Jason P; Montiel, Jorge; Shay, Jackie E ...
Annual review of ecology, evolution, and systematics,
11/2017, Letnik:
48, Številka:
1
Journal Article
Recenzirano
Odprti dostop
How ecological niche breadth evolves is central to adaptation and speciation and has been a topic of perennial interest. Niche breadth evolution research has occurred within environmental, ...ecological, evolutionary, and biogeographical contexts, and although some generalities have emerged, critical knowledge gaps exist. Performance breadth trade-offs, although long invoked, may not be common determinants of niche breadth evolution or limits. Niche breadth can expand or contract from specialist or generalist lineages, and so specialization need not be an evolutionary dead end. Whether niche breadth determines diversification and distribution breadth and how niche breadth is partitioned among individuals and populations within a species are important but particularly understudied topics. Molecular genetic and phylogenetic techniques have greatly expanded understanding of niche breadth evolution, but field studies of how niche breadth evolves are essential for providing mechanistic details and allowing the development of comprehensive theory and improved prediction of biological responses under global change.
Serpentine soils have long fascinated biologists for the specialized floras they support and the challenges they pose to plant survival and growth. This volume focuses on what scientists have learned ...about major questions in earth history, evolution, ecology, conservation, and restoration from the study of serpentine areas, especially in California. Results from molecular studies offer insight into evolutionary patterns, while new ecological research examines both species and communities. Serpentine highlights research whose breadth provides context and fresh insights into the evolution and ecology of stressful environments.
The evolutionary features and molecular innovations that enabled plants to first colonize land are not well understood. Here, insights are provided through our report of the genome sequence of the ...unicellular alga Penium margaritaceum, a member of the Zygnematophyceae, the sister lineage to land plants. The genome has a high proportion of repeat sequences that are associated with massive segmental gene duplications, likely facilitating neofunctionalization. Compared with representatives of earlier diverging algal lineages, P. margaritaceum has expanded repertoires of gene families, signaling networks, and adaptive responses that highlight the evolutionary trajectory toward terrestrialization. These encompass a broad range of physiological processes and protective cellular features, such as flavonoid compounds and large families of modifying enzymes involved in cell wall biosynthesis, assembly, and remodeling. Transcriptome profiling further elucidated adaptations, responses, and selective pressures associated with the semi-terrestrial ecosystems of P. margaritaceum, where a simple body plan would be an advantage.
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•The genome and responses of a charophyte alga uncover terrestrialization mechanisms•Paradoxical presence of protective UV-absorbing flavonoid pigments•Evolutionary origins of plant hydrophobic polymer classes that limit water loss•Expanded repertoire of genes for polysaccharide cell wall biosynthesis and remodeling
The genome sequence of Penium margaritaceum reveals that this freshwater algal species and member of the sister lineage to land plants contains several advantageous features for life on land, including an expanded repertoire of genes for cell wall biosynthesis, traces of pathways to form hydrophobic polymer classes that limit water loss, and flavonoid pigments that protect against UV radiation.
Natural selection can promote or hinder a population's evolvability-the ability to evolve new and adaptive phenotypes-but the underlying mechanisms are poorly understood. To examine how the strength ...of selection affects evolvability, we subjected populations of yellow fluorescent protein to directed evolution under different selection regimes and then evolved them toward the new phenotype of green fluorescence. Populations under strong selection for the yellow phenotype evolved the green phenotype most rapidly. They did so by accumulating mutations that increase both robustness to mutations and foldability. Under weak selection, neofunctionalizing mutations rose to higher frequency at first, but more frequent deleterious mutations undermined their eventual success. Our experiments show how selection can enhance evolvability by enhancing robustness and create the conditions necessary for evolutionary success.
We examine the behaviour of the infrared-radio correlation (IRRC) over the range 0 <z ≲ 6 using new, highly sensitive 3 GHz observations with the Karl G. Jansky Very Large Array (VLA) and infrared ...data from the Herschel Space Observatory in the 2 deg2 COSMOS field. We distinguish between objects where emission is believed to arise solely from star-formation, and those where an active galactic nucleus (AGN) is thought to be present. We account for non-detections in the radio or in the infrared using a doubly-censored survival analysis. We find that the IRRC of star-forming galaxies, quantified by the infrared-to-1.4 GHz radio luminosity ratio (qTIR), decreases with increasing redshift: qTIR(z) = (2.88 ± 0.03)(1 + z)− 0.19 ± 0.01. This is consistent with several previous results from the literature. Moderate-to-high radiative luminosity AGN do not follow the same qTIR(z) trend as star-forming galaxies, having a lower normalisation and steeper decrease with redshift. We cannot rule out the possibility that unidentified AGN contributions only to the radio regime may be steepening the observed qTIR(z) trend of the star-forming galaxy population. We demonstrate that the choice of the average radio spectral index directly affects the normalisation, as well as the derived trend with redshift of the IRRC. An increasing fractional contribution to the observed 3 GHz flux by free-free emission of star-forming galaxies may also affect the derived evolution. However, we find that the standard (M82-based) assumption of the typical radio spectral energy distribution (SED) for star-forming galaxies is inconsistent with our results. This suggests a more complex shape of the typical radio SED for star-forming galaxies, and that imperfect K corrections in the radio may govern the derived trend of decreasing qTIR with increasing redshift. A more detailed understanding of the radio spectrum is therefore required for robust K corrections in the radio and to fully understand the cosmic evolution of the IRRC. Lastly, we present a redshift-dependent relation between rest-frame 1.4 GHz radio luminosity and star formation rate taking the derived redshift trend into account.
Ever since the groundbreaking work of George Williams, W. D. Hamilton, and Richard Dawkins, evolutionary biologists have recognized that natural selection generally does not operate for the good of ...the group, but rather for the good of lower-level units such as the individual, the cell, even the gene. One of the fundamental problems of biology is: what keeps competition between these various levels of natural selection from destroying the common interests to be gained from cooperation? In this volume twelve prominent scientists explore this question, presenting a comprehensive survey of the current theoretical and empirical research in evolutionary biology. Recent studies show that at many levels of biological organization, mechanisms have evolved to prevent potential conflict in natural selection. Editor Laurent Keller's aim in this book is to bring together leading researchers from all biological disciplines to outline these potential conflicts and discuss how they are resolved. A multi-level approach of this kind allows important insights into the evolution of life, as well as bridging the long- standing conceptual chasm between molecular and organismal biologists. The chapters here follow a rigorous theoretical framework, giving the book an overall synergy that is unique to multi-authored books. The contributors, in addition to the editor, are H. Charles J. Godfray, Edward Allen Herre, Dawn M. Kitchen, Egbert Giles Leigh, Jr., Catherine M. Lessells, Richard E. Michod, Leonard Nunney, Craig Packer, Andrew Pomiankowski, H. Kern Reeve, John Maynard Smith, and Eörs Szathmáry.
Debating Design Dembski, William A; Ruse, Michael
07/2004
eBook
In this book, first published in 2004, William Dembski, Michael Ruse, and other prominent philosophers provide a comprehensive balanced overview of the debate concerning biological origins - a ...controversial dialectic since Darwin published The Origin of Species in 1859. Invariably, the source of controversy has been 'design'. Is the appearance of design in organisms (as exhibited in their functional complexity) the result of purely natural forces acting without prevision or teleology? Or, does the appearance of design signify genuine prevision and teleology, and, if so, is that design empirically detectable and thus open to scientific inquiry? Four main positions have emerged in response to these questions: Darwinism, self-organisation, theistic evolution, and intelligent design. The contributors to this volume define their respective positions in an accessible style, inviting readers to draw their own conclusions. Two introductory essays furnish a historical overview of the debate.
Electrochemical water splitting is a critical energy conversion process for producing clean and sustainable hydrogen; this process relies on low‐cost, highly active, and durable oxygen evolution ...reaction/hydrogen evolution reaction electrocatalysts. Metal cations (including transition metal and noble metal cations), particularly high‐valence metal cations that show high catalytic activity and can serve as the main active sites in electrochemical processes, have received special attention for developing advanced electrocatalysts. In this review, heterogenous electrocatalyst design strategies based on high‐valence metal sites are presented, and associated materials designed for water splitting are summarized. In the discussion, emphasis is given to high‐valence metal sites combined with the modulation of the phase/electronic/defect structure and strategies of performance improvement. Specifically, the importance of using advanced in situ and operando techniques to track the real high‐valence metal‐based active sites during the electrochemical process is highlighted. Remaining challenges and future research directions are also proposed. It is expected that this comprehensive discussion of electrocatalysts containing high‐valence metal sites can be instructive to further explore advanced electrocatalysts for water splitting and other energy‐related reactions.
High‐valence metal cations, including transition metal and noble metal cations, exhibit high catalytic activity and serve as the main active sites in electrochemical processes. This review discusses the design strategies, advances, challenges, and future directions of heterogenous electrocatalysts based on high‐valence metal sites for the application of electrochemical water splitting.
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