Research in electronic nanomaterials, historically dominated by studies of nanocrystals/fullerenes and nanowires/nanotubes, now incorporates a growing focus on sheets with nanoscale thicknesses, ...referred to as nanomembranes. Such materials have practical appeal because their two-dimensional geometries facilitate integration into devices, with realistic pathways to manufacturing. Recent advances in synthesis provide access to nanomembranes with extraordinary properties in a variety of configurations, some of which exploit quantum and other size-dependent effects. This progress, together with emerging methods for deterministic assembly, leads to compelling opportunities for research, from basic studies of two-dimensional physics to the development of applications of heterogeneous electronics.
Wearable sensors have recently seen a large increase in both research and commercialization. However, success in wearable sensors has been a mix of both progress and setbacks. Most of commercial ...progress has been in smart adaptation of existing mechanical, electrical and optical methods of measuring the body. This adaptation has involved innovations in how to miniaturize sensing technologies, how to make them conformal and flexible, and in the development of companion software that increases the value of the measured data. However, chemical sensing modalities have experienced greater challenges in commercial adoption, especially for non-invasive chemical sensors. There have also been significant challenges in making significant fundamental improvements to existing mechanical, electrical, and optical sensing modalities, especially in improving their specificity of detection. Many of these challenges can be understood by appreciating the body's surface (skin) as more of an information barrier than as an information source. With a deeper understanding of the fundamental challenges faced for wearable sensors and of the state-of-the-art for wearable sensor technology, the roadmap becomes clearer for creating the next generation of innovations and breakthroughs.
This review examines the merits of ‘food addiction’ as an explanation of excessive eating (i.e., eating in excess of what is required to maintain a healthy body weight). It describes various apparent ...similarities in appetites for foods and drugs. For example, conditioned environmental cues can arouse food and drug-seeking behaviour, ‘craving’ is an experience reported to precede eating and drug taking, ‘bingeing’ is associated with both eating and drug use, and conditioned and unconditioned tolerance occurs to food and drug ingestion. This is to be expected, as addictive drugs tap into the same processes and systems that evolved to motivate and control adaptive behaviours, including eating. The evidence, however, shows that drugs of abuse have more potent effects than foods, particularly in respect of their neuroadaptive effects that make them ‘wanted.’ While binge eating has been conceptualised as form of addictive behaviour, it is not a major cause of excessive eating, because binge eating has a far lower prevalence than obesity. Rather, it is proposed that obesity results from recurrent overconsumption of energy dense foods. Such foods are, relatedly, both attractive and (calorie for calorie) weakly satiating. Limiting their availability could partially decrease excessive eating and consequently decrease obesity. Arguably, persuading policy makers that these foods are addictive could support such action. However, blaming excessive eating on food addiction could be counterproductive, because it risks trivialising serious addictions, and because the attribution of excessive eating to food addiction implies an inability to control one's eating. Therefore, attributing everyday excessive eating to food addiction may neither explain nor significantly help reduce this problem.
•Neurobehavioral similarities between appetites for drugs and foods are to be expected.•Drugs of abuse have more potent effects than do foods.•Everyday excessive eating is not well characterised as food addiction.•Recurrent overconsumption of energy dense foods better explains obesity.•Attributing excessive eating to food addiction could be counterproductive.
This article reviews several classes of inorganic semiconductor materials that can be used to form high‐performance thin‐film transistors (TFTs) for large area, flexible electronics. Examples ranging ...from thin films of various forms of silicon to nanoparticles and nanowires of compound semiconductors are presented, with an emphasis on methods of depositing and integrating thin films of these materials into devices. Performance characteristics, including both electrical and mechanical behavior, for isolated transistors as well as circuits with various levels of complexity are reviewed. Collectively, the results suggest that flexible or printable inorganic materials may be attractive for a range of applications not only in flexible but also in large‐area electronics, from existing devices such as flat‐panel displays to more challenging (in terms of both cost and performance requirements) systems such as large area radiofrequency communication devices, structural health monitors, and conformal X‐ray imagers.
Various classes of inorganic semiconductors can be grown into high‐quality thin films to serve as channels of high‐performance thin‐film transistors (TFTs) fabricated on flexible plastic substrates, which are referred to as macroelectronics. The image shows an example of an array of TFTs built with GaAs ribbons on a thin polyurethane sheet laminated on the surface of a glass rod with diameter of 7 mm (with electrical characterization). This Review describes progress in this emerging area.
Thin current sheets (TCSs) have been postulated to be a necessary precondition for reconnection onset. Magnetic reconnection X‐lines in the magnetotail have been observed to be more common duskward ...of midnight. We take advantage of the MMS tetrahedral formation during the 2017–2020 MMS tail seasons to calculate the thickness of the cross‐tail neutral sheet relative to ion gyroradius. While a similar technique was applied to Cluster data, current sheet thickness over a broader range of radial distances has not been robustly explored before this study. We compare our analysis to recent theories regarding mechanisms of tail current sheet thinning and to recent simulations. We find MMS spent more than twice as long in ion‐scale TCSs in the pre‐midnight sector than post‐midnight, despite nearly even plasma sheet dwell time. The dawn‐dusk asymmetry in the distribution of Ion Diffusion Regions, as previously reported in relation to regions of TCSs, is also analyzed.
Plain Language Summary
Magnetic reconnection is an important mechanism for energy transfer in the magnetosphere. In order for reconnection to begin, however, the reconnecting current sheet must first become very thin. Reconnection and related phenomena have been observed in the geomagnetic tail closer to dusk than dawn on the nightside, although the reasons for this have not been clearly understood. Recent simulations of the geomagnetic tail suggest that the central current sheet in the tail should be thinner pre‐midnight than post‐midnight, possibly explaining why reconnection happens more often on the pre‐midnight than the post‐midnight sector. We use 19 months of MMS data in the tail, comprising the tail seasons of 4 years from 2017 to 2020, to estimate the thickness of the tail neutral sheet relative to relevant ion scales from dawn flank to dusk flank and both closer to and further away from the Earth than has been done in the past. We then compare the thickness we measure with the simulation predictions and with the location of previously identified reconnection locations in the same time period.
Key Points
Distribution of ion‐scale tail current sheets (CS) seen by MMS during 2017–2020 using magnetic curvature as proxy for CS thickness
Location of tail CS with thickness at or below ion gyro‐scale compared to location of reconnection‐related Ion Diffusion Regions
Observations compared to recent particle‐in‐cell simulations
The simultaneous measurement of multiple modalities represents an exciting frontier for single-cell genomics and necessitates computational methods that can define cellular states based on multimodal ...data. Here, we introduce “weighted-nearest neighbor” analysis, an unsupervised framework to learn the relative utility of each data type in each cell, enabling an integrative analysis of multiple modalities. We apply our procedure to a CITE-seq dataset of 211,000 human peripheral blood mononuclear cells (PBMCs) with panels extending to 228 antibodies to construct a multimodal reference atlas of the circulating immune system. Multimodal analysis substantially improves our ability to resolve cell states, allowing us to identify and validate previously unreported lymphoid subpopulations. Moreover, we demonstrate how to leverage this reference to rapidly map new datasets and to interpret immune responses to vaccination and coronavirus disease 2019 (COVID-19). Our approach represents a broadly applicable strategy to analyze single-cell multimodal datasets and to look beyond the transcriptome toward a unified and multimodal definition of cellular identity.
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•“Weighted nearest neighbor” analysis integrates multimodal single-cell data•A multimodal reference “atlas” of the circulating human immune system•Identification and validation of novel sources of lymphoid heterogeneity•“Reference-based” mapping of query datasets onto a multimodal atlas
A framework that allows for the integration of multiple data types using single cells is applied to understand distinct immune cell states, previously unidentified immune populations, and to interpret immune responses to vaccinations.
One way to increase cognitive capacity is to avoid duplication of functions on the left and right sides of the brain. There is a convincing body of evidence showing that such asymmetry, or ...lateralization, occurs in a wide range of both vertebrate and invertebrate species. Each hemisphere of the brain can attend to different types of stimuli or to different aspects of the same stimulus and each hemisphere analyses information using different neural processes. A brain can engage in more than one task at the same time, as in monitoring for predators (right hemisphere) while searching for food (left hemisphere). Increased cognitive capacity is achieved if individuals are lateralized in one direction or the other. The advantages and disadvantages of individual lateralization are discussed. This paper argues that directional, or population-level, lateralization, which occurs when most individuals in a species have the same direction of lateralization, provides no additional increase in cognitive capacity compared to individual lateralization although directional lateralization is advantageous in social interactions. Strength of lateralization is considered, including the disadvantage of being very strongly lateralized. The role of brain commissures is also discussed with consideration of cognitive capacity.
We demonstrate that silicon-vacancy (SiV) centers in diamond can be used to efficiently generate coherent optical photons with excellent spectral properties. We show that these features are due to ...the inversion symmetry associated with SiV centers. The generation of indistinguishable single photons from separated emitters at 5 K is demonstrated in a Hong-Ou-Mandel interference experiment. Prospects for realizing efficient quantum network nodes using SiV centers are discussed.
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