bluuebunny/crossref_metadata_2025_split huggingface dataset:
Short Chorus Wave Packets: Generation Within Chorus Elements, Statistics, and Consequences on Energetic Electron Precipitation
Authors: Mourenas D. , Zhang X.‐J. , Nunn D. , Artemyev A. V. , Angelopoulos V. , Tsai E. , Wilkins C. 
Published: May 2022

AbstractShort and intense lower‐band chorus wave packets are ubiquitous in the Earth's outer radiation belt. In this article, we perform various Vlasov hybrid simulations, with one or two triggering waves, to study the generation of short chorus packets/subpackets inside long rising tone elements. We show that the length of the generated short wave packets is consistent with a criterion of resonance non‐overlap for two independent superposed waves, and that these chorus packets have similar characteristics as in Van Allen Probes observations. We find that short wave packets are mainly formed near the middle/end of long rising tones for moderate linear growth rates, and everywhere for stronger linear growth rates. Finally, we analyze an event characterized by Time History of Events and Macroscale Interactions during Substorms spacecraft measurements of chorus rising tones near the equator and simultaneous measurements by low altitude ELFIN CubeSats of precipitating and trapped electron fluxes in the same sector. The measured precipitating electron fluxes are well recovered by test particle simulations performed using measured plasma and wave properties. We show that short chorus wave packets of moderate amplitudes (160–250 pT) essentially lead to a more diffusive‐like transport of 50–200 keV electrons toward the loss cone than long packets. In contrast, long chorus packets are found to produce important nonlinear effects via anomalous trapping, which significantly reduces electron precipitation below 150 keV, especially for higher wave amplitudes.
Water Vapor on Mars: A Refined Climatology and Constraints on the Near‐Surface Concentration Enabled by Synergistic Retrievals
Authors: Knutsen Elise W. , Montmessin Franck , Verdier Loïc , Lacombe Gaétan , Lefèvre Franck , Ferron Stéphane , Giuranna Marco , Wolkenberg Paulina , Fedorova Anna , Trokhimovskiy Alexander , Korablev Oleg 
Published: May 2022

AbstractWith the utilization of a novel synergistic approach, we constrain the vertical distribution of water vapor on Mars with measurements from nadir‐pointing instruments. Water vapor column abundances were retrieved simultaneously with PFS (sensing the thermal infrared range) and SPICAM (sensing the near‐infrared range) on Mars Express, yielding distinct yet complementary sensitivity to different parts of the atmospheric column. We show that by exploiting a spectral synergy retrieval approach, we obtain more accurate water vapor column abundances compared to when only one instrument is used, providing a new and highly robust reference climatology from Mars Express. We present a composite global data set covering all seasons and latitudes, assembled from colocated observations sampled from seven Martian years. The synergy also offers a way to study the vertical partitioning of water, which has remained out of the scope of nadir observations made by single instruments covering a single spectral interval. Special attention is given to the north polar region, with extra focus on the sublimation of the seasonal polar cap during the late spring and summer seasons. Column abundances from the Mars Climate Database were found to be significantly higher than synergistically retrieved values, especially in the summer Northern Hemisphere. Deviations between synergy and model in both magnitude and meridional variation of the vertical confinement were also discovered, suggesting that certain aspects of the transport and dynamics of water vapor are not fully captured by current models.
The Impact of Freeze‐Thaw History on Soil Carbon Response to Experimental Freeze‐Thaw Cycles
Authors: Rooney Erin C. , Bailey Vanessa L. , Patel Kaizad F. , Possinger Angela R. , Gallo Adrian C. , Bergmann Maya , SanClements Michael , Lybrand Rebecca A. 
Published: May 2022

AbstractFreeze‐thaw is a disturbance process in cold regions where permafrost soils are becoming vulnerable to temperature fluctuations above 0°C. Freeze‐thaw alters soil physical and biogeochemical properties with implications for carbon persistence and emissions in Arctic landscapes. We examined whether different freeze‐thaw histories in two soil systems led to contrasting biogeochemical responses under a laboratory‐controlled freeze‐thaw incubation. We investigated controls on carbon composition through Fourier‐transform ion cyclotron resonance mass spectrometry (FT‐ICR‐MS) to identify nominal carbon oxidation states and relative abundances of aliphatic‐type carbon molecules in both surface and subsurface soils. Soil cores (∼60 cm‐depth) were sampled from two sites in Alaskan permafrost landscapes with different in situ freeze‐thaw characteristics: Healy (>40 freeze‐thaw cycles annually) and Toolik (<15 freeze‐thaw cycles annually). FT‐ICR‐MS was coupled with in situ temperature data and soil properties (i.e., soil texture, mineralogy) to assess (a) differences in soil organic matter composition associated with previous freeze‐thaw history and (b) sensitivity to experimental freeze‐thaw in the extracted cores. Control (freeze‐only) samples showed greater carbon oxidation in Healy soils compared with Toolik, even in lower mineral horizons where freeze‐thaw history was comparable across both sites. Healy showed the most loss of carbon compounds following experimental freeze‐thaw in the lower mineral depths, including a decrease in aliphatics. Toolik soils responded more slowly to freeze‐thaw as shown by intermediary carbon oxidation distributed across multiple carbon compound classes. Variations in the response of permafrost carbon chemistry to freeze‐thaw is an important factor for predicting changes in soil function as permafrost thaws in high northern latitudes.
Pancharatnam–Berry phase reversal via opposite-chirality-coexisted superstructures
Authors: Zhu Lin , Xu Chun-Ting , Chen Peng , Zhang Yi-Heng , Liu Si-Jia , Chen Quan-Ming , Ge Shi-Jun , Hu Wei , Lu Yan-Qing 
Published: May 2022

AbstractRecently discovered reflective Pancharatnam–Berry phase (PB phase) from chiral anisotropic media (e.g., cholesteric liquid crystal, CLC) has aroused great interest in the emerging frontier of planar optics. However, the single chirality of common CLCs results in the intrinsic limitation of the same spin-selective PB phase manipulation, which means the reversal of the input spin cannot realize the conjugated PB phase. In this work, an innovative scheme based on opposite-chirality-coexisted superstructures is proposed to simultaneously modulate orthogonal circular polarization and get PB phase reversal. Through refilling CLC into a washed-out polymer network with opposite chirality and delicate photo-patterned structures, reflective optical vortex (OV) with opposite topological charges and vector beams with conjugated spiral PB phases are efficiently generated depending on the incident polarization. Furthermore, OV holograms are encoded to reconstruct polarization-selective OV arrays, indicating the strong capability of such opposite-chirality-coexisted anisotropic media. This work provides a new compact platform for planar optics, and sheds light on the architectures and functionalities of chiral superstructures.
Genome-wide tandem repeat expansions contribute to schizophrenia risk
Authors: Mojarad Bahareh A. , Engchuan Worrawat , Trost Brett , Backstrom Ian , Yin Yue , Thiruvahindrapuram Bhooma , Pallotto Linda , Mitina Aleksandra , Khan Mahreen , Pellecchia Giovanna , Haque Bushra , Guo Keyi , Heung Tracy , Costain Gregory , Scherer Stephen W. , Marshall Christian R. , Pearson Christopher E. , Bassett Anne S. , Yuen Ryan K. C. 
Published: May 2022

AbstractTandem repeat expansions (TREs) can cause neurological diseases but their impact in schizophrenia is unclear. Here we analyzed genome sequences of adults with schizophrenia and found that they have a higher burden of TREs that are near exons and rare in the general population, compared with non-psychiatric controls. These TREs are disproportionately found at loci known to be associated with schizophrenia from genome-wide association studies, in individuals with clinically-relevant genetic variants at other schizophrenia loci, and in families where multiple individuals have schizophrenia. We showed that rare TREs in schizophrenia may impact synaptic functions by disrupting the splicing process of their associated genes in a loss-of-function manner. Our findings support the involvement of genome-wide rare TREs in the polygenic nature of schizophrenia.
Large differences in carbohydrate degradation and transport potential among lichen fungal symbionts
Authors: Resl Philipp , Bujold Adina R. , Tagirdzhanova Gulnara , Meidl Peter , Freire Rallo Sandra , Kono Mieko , Fernández-Brime Samantha , Guðmundsson Hörður , Andrésson Ólafur Sigmar , Muggia Lucia , Mayrhofer Helmut , McCutcheon John P. , Wedin Mats , Werth Silke , Willis Lisa M. , Spribille Toby 
Published: May 2022

AbstractLichen symbioses are thought to be stabilized by the transfer of fixed carbon from a photosynthesizing symbiont to a fungus. In other fungal symbioses, carbohydrate subsidies correlate with reductions in plant cell wall-degrading enzymes, but whether this is true of lichen fungal symbionts (LFSs) is unknown. Here, we predict genes encoding carbohydrate-active enzymes (CAZymes) and sugar transporters in 46 genomes from the Lecanoromycetes, the largest extant clade of LFSs. All LFSs possess a robust CAZyme arsenal including enzymes acting on cellulose and hemicellulose, confirmed by experimental assays. However, the number of genes and predicted functions of CAZymes vary widely, with some fungal symbionts possessing arsenals on par with well-known saprotrophic fungi. These results suggest that stable fungal association with a phototroph does not in itself result in fungal CAZyme loss, and lends support to long-standing hypotheses that some lichens may augment fixed CO2 with carbon from external sources.
Chiral self-assembly of cellulose nanocrystals is driven by crystallite bundles
Authors: Parton Thomas G. , Parker Richard M. , van de Kerkhof Gea T. , Narkevicius Aurimas , Haataja Johannes S. , Frka-Petesic Bruno , Vignolini Silvia 
Published: May 2022

AbstractThe transfer of chirality across length-scales is an intriguing and universal natural phenomenon. However, connecting the properties of individual building blocks to the emergent features of their resulting large-scale structure remains a challenge. In this work, we investigate the origins of mesophase chirality in cellulose nanocrystal suspensions, whose self-assembly into chiral photonic films has attracted significant interest. By correlating the ensemble behaviour in suspensions and films with a quantitative morphological analysis of the individual nanoparticles, we reveal an inverse relationship between the cholesteric pitch and the abundance of laterally-bound composite particles. These ‘bundles’ thus act as colloidal chiral dopants, analogous to those used in molecular liquid crystals, providing the missing link in the hierarchical transfer of chirality from the molecular to the colloidal scale.
Molecular insights into biogenesis of glycosylphosphatidylinositol anchor proteins
Authors: Xu Yidan , Jia Guowen , Li Tingting , Zhou Zixuan , Luo Yitian , Chao Yulin , Bao Juan , Su Zhaoming , Qu Qianhui , Li Dianfan 
Published: May 2022

AbstractEukaryotic cells are coated with an abundance of glycosylphosphatidylinositol anchor proteins (GPI-APs) that play crucial roles in fertilization, neurogenesis, and immunity. The removal of a hydrophobic signal peptide and covalent attachment of GPI at the new carboxyl terminus are catalyzed by an endoplasmic reticulum membrane GPI transamidase complex (GPI-T) conserved among all eukaryotes. Here, we report the cryo-electron microscopy (cryo-EM) structure of the human GPI-T at a global 2.53-Å resolution, revealing an equimolar heteropentameric assembly. Structure-based mutagenesis suggests a legumain-like mechanism for the recognition and cleavage of proprotein substrates, and an endogenous GPI in the structure defines a composite cavity for the lipid substrate. This elongated active site, stemming from the membrane and spanning an additional ~22-Å space toward the catalytic dyad, is structurally suited for both substrates which feature an amphipathic pattern that matches this geometry. Our work presents an important step towards the mechanistic understanding of GPI-AP biosynthesis.
Signal transduction in light-oxygen-voltage receptors lacking the active-site glutamine
Authors: Dietler Julia , Gelfert Renate , Kaiser Jennifer , Borin Veniamin , Renzl Christian , Pilsl Sebastian , Ranzani Américo Tavares , García de Fuentes Andrés , Gleichmann Tobias , Diensthuber Ralph P. , Weyand Michael , Mayer Günter , Schapiro Igor , Möglich Andreas 
Published: May 2022

AbstractIn nature as in biotechnology, light-oxygen-voltage photoreceptors perceive blue light to elicit spatiotemporally defined cellular responses. Photon absorption drives thioadduct formation between a conserved cysteine and the flavin chromophore. An equally conserved, proximal glutamine processes the resultant flavin protonation into downstream hydrogen-bond rearrangements. Here, we report that this glutamine, long deemed essential, is generally dispensable. In its absence, several light-oxygen-voltage receptors invariably retained productive, if often attenuated, signaling responses. Structures of a light-oxygen-voltage paradigm at around 1 Å resolution revealed highly similar light-induced conformational changes, irrespective of whether the glutamine is present. Naturally occurring, glutamine-deficient light-oxygen-voltage receptors likely serve as bona fide photoreceptors, as we showcase for a diguanylate cyclase. We propose that without the glutamine, water molecules transiently approach the chromophore and thus propagate flavin protonation downstream. Signaling without glutamine appears intrinsic to light-oxygen-voltage receptors, which pertains to biotechnological applications and suggests evolutionary descendance from redox-active flavoproteins.
Electromagnetic wave-based extreme deep learning with nonlinear time-Floquet entanglement
Authors: Momeni Ali , Fleury Romain 
Published: May 2022

AbstractWave-based analog signal processing holds the promise of extremely fast, on-the-fly, power-efficient data processing, occurring as a wave propagates through an artificially engineered medium. Yet, due to the fundamentally weak non-linearities of traditional electromagnetic materials, such analog processors have been so far largely confined to simple linear projections such as image edge detection or matrix multiplications. Complex neuromorphic computing tasks, which inherently require strong non-linearities, have so far remained out-of-reach of wave-based solutions, with a few attempts that implemented non-linearities on the digital front, or used weak and inflexible non-linear sensors, restraining the learning performance. Here, we tackle this issue by demonstrating the relevance of time-Floquet physics to induce a strong non-linear entanglement between signal inputs at different frequencies, enabling a power-efficient and versatile wave platform for analog extreme deep learning involving a single, uniformly modulated dielectric layer and a scattering medium. We prove the efficiency of the method for extreme learning machines and reservoir computing to solve a range of challenging learning tasks, from forecasting chaotic time series to the simultaneous classification of distinct datasets. Our results open the way for optical wave-based machine learning with high energy efficiency, speed and scalability.
Medial packing and elastic asymmetry stabilize the double-gyroid in block copolymers
Authors: Reddy Abhiram , Dimitriyev Michael S. , Grason Gregory M. 
Published: May 2022

AbstractTriply-periodic networks are among the most complex and functionally valuable self-assembled morphologies, yet they form in nearly every class of biological and synthetic soft matter building blocks. In contrast to simpler assembly motifs – spheres, cylinders, layers – networks require molecules to occupy variable local environments, confounding attempts to understand their formation. Here, we examine the double-gyroid network phase by using a geometric formulation of the strong stretching theory of block copolymer melts, a prototypical soft self-assembly system. The theory establishes the direct link between molecular packing, assembly thermodynamics and the medial map, a generic measure of the geometric center of complex shapes. We show that “medial packing” is essential for stability of double-gyroid in strongly-segregated melts, reconciling a long-standing contradiction between infinite- and finite-segregation theories. Additionally, we find a previously unrecognized non-monotonic dependence of network stability on the relative entropic elastic stiffness of matrix-forming to tubular-network forming blocks. The composition window of stable double-gyroid widens for both large and small elastic asymmetry, contradicting intuitive notions that packing frustration is localized to the tubular domains. This study demonstrates the utility of optimized medial tessellations for understanding soft-molecular assembly and packing frustration via an approach that is readily generalizable far beyond gyroids in neat block copolymers.
Pathologic complete response and survival after neoadjuvant chemotherapy in cT1-T2/N0 HER2+ breast cancer
Authors: An Selena J. , Duchesneau Emilie D. , Strassle Paula D. , Reeder-Hayes Katherine , Gallagher Kristalyn K. , Ollila David W. , Downs-Canner Stephanie M. , Spanheimer Philip M. 
Published: May 2022

AbstractWomen with small HER2+ breast cancers may have excellent prognosis with adjuvant single-agent chemotherapy and HER2-targeted therapy. The role of de-escalated therapy in the neoadjuvant setting, however, remains uncertain. We conducted a cohort study of adult women with T1-2/cN0 HER2+ breast cancer diagnosed 2013–2016 in the National Cancer Database treated with neoadjuvant chemotherapy (NAC) and HER2-targeted therapy. Factors associated with pathologic complete response (pCR) and overall survival were examined. In total, 6994 patients were included, 32% cT1 and 68% cT2. Multi-agent NAC was given to 90% of women while single-agent NAC was given to 10% of women. pCR was achieved in 46% of cT2 patients and 43% of cT1, and in 46% of patients treated with multi-agent versus 38% single agent. Patients receiving multi-agent chemotherapy were younger, had fewer comorbidities, and had higher cT stage and grade. In all patients, pCR was associated with improved survival (p < 0.01). Multi-agent chemotherapy (OR 1.3, p = 0.003), hormone receptor negative (OR 2.6, p < 0.001), higher grade (OR 2.2, p < 0.001), younger age (OR 1.4, p = 0.011), and later year of diagnosis (OR 1.3, p = 0.005) were associated with achieving pCR. Multi-agent chemotherapy was associated with higher likelihood of pCR, but this effect was modest compared to other factors. Single-agent NAC with HER2-directed therapy in selected patients may provide excellent outcome with reduced toxicity, while allowing escalated therapy in the adjuvant setting for patients with residual disease. Prospective studies are needed to determine effects of de-escalation in the neoadjuvant setting on survival and optimal selection strategies.
Mechanisms of the epitaxial growth of two-dimensional polycrystals
Authors: Dong Jichen , Liu Yunqi , Ding Feng 
Published: May 2022

AbstractIn the epitaxial growth of two-dimensional (2D) materials on substrates, 2D polycrystals with various shapes have been broadly observed, but their formation mechanisms are still highly elusive. Here we present a complete study on the formation mechanisms of various 2D polycrystals. The structures of the 2D polycrystals are dependent on the symmetries of both the 2D material and the substrate. We build four complete libraries of 2D polycrystals for (i) threefold symmetric 2D materials on two- or six-fold symmetric substrates (i.e., family-III/II or -III/VI), (ii) threefold symmetric 2D materials on fourfold symmetric substrates (i.e. family-III/IV), (iii) fourfold symmetric 2D materials on three- or six-fold symmetric substrates (i.e., family-IV/III or -IV/VI), and (iv) sixfold symmetric 2D materials on fourfold symmetric substrates (i.e., family-VI/IV), respectively. The four libraries of 2D polycrystals are consistent with many existing experimental observations and can be used to guide the experimental synthesis of various 2D polycrystals.
Antimicrobial enhancement via Cerium (II)/Lanthanum (III)‐doped TiO2 for emergency leak sealing polyurea coating system
Authors: Li Yuanzhe , Fang Cong , Zhuang Wei-Qin , Wang Haojing , Wang Xueli 
Published: May 2022

AbstractIndustrial piping structures often suffer from corrosion caused by biofouling or chemical etching, which can cause immediate structural failure. Polyurea coatings, which are fabricated for emergency leak sealing, are able to form high mechanical strength coating surfaces within seconds. After its further modification via Ce/La-doped TiO2, the polyurea coating will indicate an increment in mechanical strength, chemical durability, and reduction of microbial attachment. Due to the adsorption by the Ce/La-doped TiO2 and generation of reactive oxygen species (ROS), E. coli and Pseudomonas may lose their living conditions during the progress, and planktonic bacteria cells are prevented from enriching on the surface. The Ce/La‐dopants can also improve the original photocatalytic response of nano-TiO2 to UV light and environmental temperature. These Ce/La-doped TiO2 polyurea coatings illustrate an immediate application for emergency leak sealing purposes without any production interruption and it may prolong the time intervals for the maintenance service as well.
Neuropathology of Parkinson’s disease after focused ultrasound thalamotomy
Authors: Koga Shunsuke , Ishaque Mariam , Jeffrey Elias W. , Shah Binit B. , Murakami Aya , Dickson Dennis W. 
Published: May 2022

AbstractFocused ultrasound (FUS) thalamotomy is an emerging treatment for tremor-dominant Parkinson’s disease (PD). We report the first postmortem neuropathologic study of FUS thalamotomy in a 68-year-old man with tremor-dominant PD, which was performed seven months before he died. Although the peak voxel temperature at the target was <54 °C, his tremor improved on intraoperative and postoperative assessments. Additionally, postoperative MRI demonstrated a thalamic lesion. Lewy body-related pathology consistent with PD was detected. There was also a 5-mm lesion in the ventral lateral thalamus characterized by demyelination and neuropil loss, with many lipid-laden macrophages, but no lymphocytic infiltrates and relatively preserved neurons and axons. Additional pathological assessments after FUS thalamotomy are needed to determine if the observed brain changes are typical of this procedure.