Multiscale Investigation of Sodium-Ion Battery Anodes: Analytical Techniques and Applications

The anode/electrolyte interface behavior, and by extension, the overall cell performance of sodium-ion batteries is determined by a complex interaction of processes that occur at all components of the electrochemical cell across a wide range of size- and timescales. Single-scale studies may provide incomplete insights, as they cannot capture the full picture of this complex and intertwined behavior. Broad, multiscale studies are essential to elucidate these processes. Within this perspectives article, several analytical and theoretical techniques are introduced, and described how they can be combined to provide a more complete and comprehensive understanding of sodium-ion battery (SIB) performance throughout its lifetime, with a special focus on the interfaces of hard carbon anodes. These methods target various length- and time scales, ranging from micro to nano, from cell level to atomistic structures, and account for a broad spectrum of physical and (electro)chemical characteristics. Specifically, how mass spectrometric, microscopic, spectroscopic, electrochemical, thermodynamic, and physical methods can be employed to obtain the various types of information required to understand battery behavior will be explored. Ways are then discussed how these methods can be coupled together in order to elucidate the multiscale phenomena at the anode interface and develop a holistic understanding of their relationship to overall sodium-ion battery function.     

Rejoinder to Use of Principal Component Analysis and the GE -Biplot for the Graphical Exploration of Gene Expression Data

Summary This note is in response to Wouters et al. (2003, Biometrics 59, 1131–1139) who compared three methods for exploring gene expression data. Contrary to their summary that principal component analysis is not very informative, we show that it is possible to determine principal component analyses that are useful for exploratory analysis of microarray data. We also present another biplot representation, the GE‐biplot (Gene Expression biplot), that is a useful method for exploring gene expression data with the major advantage of being able to aid interpretation of both the samples and the genes relative to each other.     

Localization of vacuolar transport receptors and cargo proteins in the Golgi apparatus of developing Arabidopsis embryos

Using immunogold electron microscopy, we have investigated the relative distribution of two types of vacuolar sorting receptors (VSR) and two different types of lumenal cargo proteins, which are potential ligands for these receptors in the secretory pathway of developing Arabidopsis embryos. Interestingly, both cargo proteins are deposited in the protein storage vacuole, which is the only vacuole present during the bent-cotyledon stage of embryo development. Cruciferin and aleurain do not share the same pattern of distribution in the Golgi apparatus. Cruciferin is mainly detected in the cis and medial cisternae, especially at the rims where storage proteins aggregate into dense vesicles (DVs). Aleurain is found throughout the Golgi stack, particularly in the trans cisternae and trans Golgi network where clathrin-coated vesicles (CCVs) are formed. Nevertheless, aleurain was detected in both DV and CCV. VSR-At1, a VSR that recognizes N-terminal vacuolar sorting determinants (VSDs) of the NPIR type, localizes mainly to the trans Golgi and is hardly detectable in DV. Receptor homology-transmembrane-RING H2 domain (RMR), a VSR that recognizes C-terminal VSDs, has a distribution that is very similar to that of cruciferin and is found in DV. Our results do not support a role for VSR-At1 in storage protein sorting, instead RMR proteins because of their distribution similar to that of cruciferin in the Golgi apparatus and their presence in DV are more likely candidates. Aleurain, which has an NPIR motif and seems to be primarily sorted via VSR-At1 into CCV, also possesses putative hydrophobic sorting determinants at its C-terminus that could allow the additional incorporation of this protein into DV.     

Genital damage in the orb-web spider Argiope bruennichi (Araneae: Araneidae) increases paternity success

The morphology of male genitalia often suggests functions besidessperm transfer that may have evolved under natural or sexualselection. In several species of sexually cannibalistic spiders,males damage their paired genitalia during mating, limitingthem to one copulation per pedipalp. Using a triple-mating experiment,we tested if genital damage in the orb-web spider Argiope bruennichiincreases male fitness either through facilitating his escapefrom an aggressive female or by obstructing the female's inseminationducts against future copulation attempts from other males. Wefound no survival advantage for males damaging their pedipalps;however, copulations into a previously used insemination ductwere significantly shorter when the previous male had left partsof his genitalia inside the insemination duct. Because copulationduration determines paternity in this species, our result suggeststhat male genital damage in A. bruennichi is sexually selected.By breaking off parts of their intromittent organs inside avirgin female, males can reduce sperm competition and therebyincrease their paternity success.     

Alternative complex formation of the Ca-regulated protein kinase CIPK1 controls abscisic acid-dependent and independent stress responses in Arabidopsis

Intracellular release of calcium ions belongs to the earliest events in cellular stress perception. The molecular mechanisms integrating signals from different environmental cues and translating them into an optimized response are largely unknown. We report here the functional characterization of CIPK1, a protein kinase interacting strongly with the calcium sensors CBL1 and CBL9. Comparison of the expression patterns indicates that the three proteins execute their functions in the same tissues. Physical interaction of CIPK1 with CBL1 and CBL9 targets the kinase to the plasma membrane. We show that, similarly to loss of CBL9 function, mutation of either CBL1 or CIPK1 renders plants hypersensitive to osmotic stress. Remarkably, in contrast to the cbl1 mutant and similarly to the cbl9 mutant, loss of CIPK1 function impairs abscisic acid (ABA) responsiveness. We therefore suggest that, by alternative complex formation with either CBL1 or CBL9, the kinase CIPK1 represents a convergence point for ABA-dependent and ABA-independent stress responses. Based on our genetic, physiological and protein-protein interaction data, we propose a general model for information processing in calcium-regulated signalling networks.     

Risk assessment based on indirect predation cues: revisiting fine‐grained variation

To adaptively express inducible defenses, prey must gauge risk based on indirect cues of predation. However, the information contained in indirect cues that enable prey to fine‐tune their phenotypes to variation in risk is still unclear. In aquatic systems, research has focused on cue concentration as the key variable driving threat‐sensitive responses to risk. However, while risk is measured as individuals killed per time, cue concentration may vary with either the number or biomass killed. Alternatively, fine‐grained variation in cue, that is, frequency of cue pulses irrespective of concentration, may provide a more reliable signal of risk. Here, we present results from laboratory experiments that examine the relationship between red‐eyed treefrog tadpole growth and total cue, cue per pulse, and cue pulse frequency. We also reanalyze an earlier study that examined the effect of fine‐grained variation in predator cues on wood frog tadpole growth. Both studies show growth declines with increasing cue pulse frequency, even though individual pulses in high‐frequency treatments contained very little cue. This result suggests that counter to earlier conclusions, tadpoles are using fine‐grained variation in cue arising from the number of predation events to assess and respond to predation risk, as predicted by consumer–resource theory.