Hyperspectral images (HSIs) have gained high spectral resolution due to recent advances in spectral imaging technologies. This incurs problems, such as an increased data scale and an increased number ...of bands for HSIs, which results in a complex correlation between different bands. In the applications of remote sensing and earth observation, ground objects represented by each HSI pixel are composed of physical and chemical non-Euclidean structures, and HSI classification (HIC) is becoming a more challenging task. To solve the above problems, we propose a framework based on a deep attention graph convolutional network (DAGCN). Specifically, we first integrate an attention mechanism into the spectral similarity measurement to aggregate similar spectra. Therefore, we propose a new similarity measurement method, i.e., the mixed measurement of a kernel spectral angle mapper and spectral information divergence (KSAM-SID), to aggregate similar spectra. Considering the non-Euclidean structural characteristics of HSIs, we design deep graph convolutional networks (DeepGCNs) as a feature extraction method to extract deep abstract features and explore the internal relationship between HSI data. Finally, we dynamically update the attention graph adjacency matrix to adapt to the changes in each feature graph. Experiments on three standard HSI data sets, namely, the Indian Pines, Pavia University, and Salinas data sets, demonstrate that the DAGCN outperforms the baselines in terms of various evaluation criteria. For example, on the Indian Pines data set, the overall accuracy of the proposed method achieves 98.61% when the training sample is 10%.
Lignin-based pH-responsive nanocapsules were successfully fabricated via an interfacial miniemulsion polymerization. Lignin was first grafted with allyl groups through etherification and further ...dispersed in an oil-in-water (O/W) miniemulsion system via ultrasonication. Then allyl-functionalized lignin was reacted with a thiol-based cross-linking agent in the interfaces of miniemulsion droplets to form nanocapsules via a thiol–ene radical reaction. The FTIR and 1H NMR spectra indicated the successful grafting of allyl groups on lignin. TEM images showed that lignin nanocapsules had particle sizes ranging from 50 to 300 nm. These newly synthesized nanocapsules could be readily loaded with hydrophobic coumarin-6 during the preparation of a miniemulsion system with 0.713 mmol/g entrapment efficiency. Moreover, the release of encapsulated coumarin-6 could be controlled by varying pH in the solution due to the existence of acid-labile β-thiopropionate cross-linkages in the capsule shell. An approximately linear release profile was observed at pH 7.4, whereas the release followed a Korsmeyer–Peppas profile at pH 4. The syntheses of lignin-based nanocapsules not only provide a facile approach to utilize the waste biomaterials from biorefinery industries, but also have great potential for applications in a controllable delivery of hydrophobic molecules such as drugs, essential oils, antioxidants, etc.
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IJS, KILJ, NUK, PNG, UL, UM
Background
Inequities in COVID-19 outcomes in the USA have been clearly documented for sex and race: men are dying at higher rates than women, and Black individuals are dying at higher rates than ...white individuals. Unexplored, however, is how sex and race interact in COVID-19 outcomes.
Objective
Use available data to characterize COVID-19 mortality rates within and between race and sex strata in two US states, with the aim of understanding how apparent sex disparities in COVID-19 deaths vary across race.
Design and Participants
This observational study uses COVID-19 mortality data through September 21, 2020, from Georgia (GA) and Michigan (MI).
Main Measures
We calculate age-specific rates for each sex-race-age stratum, and age-standardized rates for each race-sex stratum. We investigate the sex disparity within race groups and the race disparity within sex groups using age-standardized rate ratios, and rate differences.
Key Results
Within race groups, men have a higher COVID-19 mortality rate than women. Black men have the highest rate of all race-sex groups (in MI: 254.6, deaths per 100,000, 95% CI: 241.1–268.2, in GA:128.5, 95% CI: 121.0-135.9). In MI, the COVID-19 mortality rate for Black women (147.1, 95% CI: 138.7–155.4) is higher than the rate for white men (39.1, 95% CI: 37.3–40.9), white women (29.7, 95% CI: 28.3–31.0), and Asian/Pacific Islander men and women. COVID-19 mortality rates in GA followed the same pattern. In MI, the male:female mortality rate ratio among Black individuals is 1.7 (1.5–2.0) while the rate ratio among White individuals is only 1.3 (1.2–1.5).
Conclusion
While overall, men have higher COVID-19 mortality rates than women, our findings show that this sex disparity does not hold across racial groups. This demonstrates the limitations of unidimensional reporting and analyses and highlights the ways that race and gender intersect to shape COVID-19 outcomes.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Human arboviral diseases transmitted by Aedes aegypti such as dengue, Zika, chikungunya and yellow fever remain global public health threats to date. Of these diseases, dengue fever is particularly ...prevalent in Southeast Asia. Relentless vector control efforts are performed to curtail disease transmissions through which pyrethroid insecticides are broadly used as the first line of defense to control Ae. aegypti, especially in the course of disease outbreaks. Here, we compile the largest contemporary database for susceptibility profiles and underlying mechanisms involved in Ae. aegypti resistant to pyrethroids in Southeast Asia. The extensive use of pyrethroids inevitably elicit different levels of resistance to numerous populations despite the presence of geographical isolation. The most common mechanisms of pyrethroid resistance that have been identified in Ae. aegypti includes mutations in the voltage sensitive sodium channel gene (Vssc gene) and metabolic-mediated insecticide resistance. Aedes aegypti develops resistance to pyrethroids by acquisition of one or several amino acid substitution(s) in this Vssc gene. Enzymes involved in metabolic-mediated detoxification (i.e. monooxygenases, glutathione-S-transferases and esterases) have been reported to be related to pyrethroid resistance but many specific contributory enzymes are not completely studied. An inadequate amount of data from some countries indicates an urgent need for further study to fill the knowledge gaps. Perspectives and future research needs are also discussed.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Immunological memory is required for protection against repeated infections and is the basis of all effective vaccines. Antibodies produced by memory B cells play an essential role in many of these ...responses. We have combined lineage tracing with antibody cloning from single B cells to examine the role of affinity in B cell selection into germinal centers (GCs) and the memory B cell compartment in mice immunized with an HIV-1 antigen. We find that contemporaneously developing memory and GC B cells differ in their affinity for antigen throughout the immune response. Whereas GC cells and their precursors are enriched in antigen binding, memory B cells are not. Thus, the polyclonal memory B cell compartment is composed of B cells that were activated during the immune response but whose antigen binding affinity failed to support further clonal expansion in the GC.
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•Memory B cell lineage tracing is combined with single B cell antibody cloning•In immunized mice, memory B cells differentiate from low-affinity precursors•Contemporaneously developing germinal center B cells are enriched for antigen binding•Low-affinity memory B cells can be recalled in new germinal center reactions
Using an unbiased fate mapping approach in immunized mice with intact immune systems, Viant et al. show that contemporaneously developing memory and GC B cells differ in their affinity for antigen throughout the immune response. GC cells are enriched in antigen binding, but memory B cells are not. Moreover, the affinity difference is unrelated to the number of somatic mutations and is already present in precursors cells, with higher-affinity cells preferentially entering the GC.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The evolution of polygonal‐shaped nanoholes on the (100) surface of germanium, aided by focused ion beam induced self‐organization, is presented. The energetic beam of ions creates a viscous phase ...which, at a thermodynamical minimum, leads to surface self‐organization. A directed viscous‐flow along the predefined nanoholes provides well‐ordered polygonal nanostructures, ranging from triangles to hexagons and octagons, as desired. The amorphization exhibiting a confined viscous‐flow at the walls of nanoholes is attributed to the localized melting zones induced by site‐specific thermal spikes during ion irradiation, as revealed by microscopy and molecular dynamics studies. This leads to a local self‐organization in the vicinity of each circular nanohole via a viscous‐fingering process at the nanoscale. Such controlled self‐organization, with the help of a predefined scanning grid, transforms the circular holes into the desired polygonal shape. The present morphology manipulation promises to surmount the barriers concerning the size reduction efforts in the field of nanofabrication.
An easy and single‐step method to manipulate the morphology of circular nanoholes via ion beam irradiation is presented. Through nanoscale control over self‐organization process dynamics on the (100) surface of germanium, polygonal structures such as squares, triangles, and hexagons are realized. Highly periodic and protruding nanoscale‐polygons indicate potential applications toward hierarchical and 3D nanostructures for multifunctional nanodevices.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Leptin informs the brain about sufficiency of fuel stores. When insufficient, leptin levels fall, triggering compensatory increases in appetite. Falling leptin is first sensed by hypothalamic ...neurons, which then initiate adaptive responses. With regard to hunger, it is thought that leptin-sensing neurons work entirely via circuits within the central nervous system (CNS). Very unexpectedly, however, we now show this is not the case. Instead, stimulation of hunger requires an intervening endocrine step, namely activation of the hypothalamic–pituitary–adrenocortical (HPA) axis. Increased corticosterone then activates AgRP neurons to fully increase hunger. Importantly, this is true for 2 forms of low leptin-induced hunger, fasting and poorly controlled type 1 diabetes. Hypoglycemia, which also stimulates hunger by activating CNS neurons, albeit independently of leptin, similarly recruits and requires this pathway by which HPA axis activity stimulates AgRP neurons. Thus, HPA axis regulation of AgRP neurons is a previously underappreciated step in homeostatic regulation of hunger.
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
Organic–inorganic hybrid perovskite solar cells with mixed cations and mixed halides have achieved impressive power conversion efficiency of up to 22.1%. Phase segregation due to the mixed ...compositions has attracted wide concerns, and their nature and origin are still unclear. Some very useful analytical techniques are controversial in microstructural and chemical analyses due to electron beam‐induced damage to the “soft” hybrid perovskite materials. In this study photoluminescence, cathodoluminescence, and transmission electron microscopy are used to study charge carrier recombination and retrieve crystallographic and compositional information for all‐inorganic CsPbIBr2 films on the nanoscale. It is found that under light and electron beam illumination, “iodide‐rich” CsPbI(1+x)Br(2−x) phases form at grain boundaries as well as segregate as clusters inside the film. Phase segregation generates a high density of mobile ions moving along grain boundaries as ion migration “highways.” Finally, these mobile ions can pile up at the perovskite/TiO2 interface resulting in formation of larger injection barriers, hampering electron extraction and leading to strong current density–voltage hysteresis in the polycrystalline perovskite solar cells. This explains why the planar CsPbIBr2 solar cells exhibit significant hysteresis in efficiency measurements, showing an efficiency of up to 8.02% in the reverse scan and a reduced efficiency of 4.02% in the forward scan, and giving a stabilized efficiency of 6.07%.
Iodide‐rich phase segregation near grain boundaries and the formation of iodide‐rich “clusters” inside the film are observed in the CsPbIBr2 perovskite thin films. The mobile ions generated by the phase segregation, moving alone grainboundaries and piling up at CsPbIBr2/TiO2 interface, can become charge injection barriers and exacerbate the current density–voltage hysteresis in inorganic CsPbIBr2 solar cells.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Water (H2O), one of the most ubiquitous molecules in the universe, has bright millimeter-wave emission lines that are easily observed at high redshift with the current generation of instruments. The ...low-excitation transition of H2O, ( rest = 987.927 GHz), is known to trace the far-infrared (FIR) radiation field independent of the presence of active galactic nuclei (AGNs) over many orders of magnitude in FIR luminosity ( ). This indicates that this transition arises mainly due to star formation. In this paper, we present spatially (∼0 5 corresponding to ∼1 kiloparsec) and spectrally resolved (∼100 kms−1) observations of in a sample of four strong gravitationally lensed high-redshift galaxies with the Atacama Large Millimeter/submillimeter Array. In addition to increasing the sample of luminous (>1012 L ) galaxies observed with H2O, this paper examines the relation on resolved scales for the first time at high redshift. We find that is correlated with on both global and resolved kiloparsec scales within the galaxy in starbursts and AGN with average . We find that the scatter in the observed relation does not obviously correlate with the effective temperature of the dust spectral energy distribution or the molecular gas surface density. This is a first step in developing as a resolved star formation rate calibrator.
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