bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lunar Impact Glasses: Probing the Moon's Surface and Constraining its Impact History
Authors: Zellner N. E. B. 
Published: October 2019

AbstractLunar impact glasses, formed during impact events when the regolith is quenched during the ejecta's ballistic flight, are small samples whose information can lead to important advances in studies of the Moon. For example, they provide evidence that constrains both the compositional evolution of the lunar crust and the timing of the lunar impact flux starting at ~4,000 million years ago. They are abundant in the lunar regolith and retain geochemical information that tells us where and when they formed. Thus, they provide important details about areas of the Moon both sampled and not sampled by Apollo or Luna missions or lunar meteorites. Additionally, as a result of these glasses possessing a chemical memory of formation location and age, studies of lunar impact glasses provide a foundation on which to conduct studies of impact glasses from other planetary bodies. A summary of past and current lunar impact glass investigations, using glasses from the Apollo 11, 12, 14, 15, 16, and 17 regoliths, along with plans for future work, will be presented.
High‐Resolution Thermal Environment of Recurring Slope Lineae in Palikir Crater, Mars, and Its Implications for Volatiles
Authors: Schorghofer N. , Levy J.S. , Goudge T.A. 
Published: October 2019

AbstractA thermophysical model for rough terrain is developed that is capable of processing spatial domains of megapixel size. This computational advance makes it possible to characterize thermal environments on Mars at unprecedented scale and at a resolution of 1 m per pixel. The model is applied to Palikir Crater, Mars, where many recurring slope lineae (RSL) are located, often in bedrock alcoves. In areas with RSL, subsurface water ice is not stable, that is, any subsurface ice is lost to the atmosphere in the long term. On large portions of the craters walls, water frost accumulates continuously for up to hundreds of sols each Mars year, but no relation is found between the location of RSL and seasonal water frost accumulation. Some RSL do not have access to even 1 m2 of water frost, at any time of the year. Where water frost is present, it stops accumulating in early southern spring at the latest, long before major RSL activity. Based on the model results, neither CO2 frost, perennial subsurface ice, nor seasonal water frost patches (>1 m2) are connected with RSL activity.
Extensive Polygonal Fracture Network in Siccar Point group Strata: Fracture Mechanisms and Implications for Fluid Circulation in Gale Crater, Mars
Authors: Kronyak R. E. , Kah L. C. , Miklusicak N. B. , Edgett K. S. , Sun V. Z. , Bryk A. B. , Williams R. M. E. 
Published: October 2019

AbstractRock fractures are indicators of stress release within geologic systems, and fracture morphologies can commonly be used to infer formation conditions. Polygonal fractures are common in isotropic, contractional stress regimes such as in rocks exposed at the surface of a planet undergoing thermal cycling or in sedimentary substrates undergoing repeated wetting and drying. Such polygonal fracture systems, on centimeter to decameter scales, have been widely documented on Mars. Utilizing a combination of orbital‐ and ground‐based images, we report a laterally extensive polygonal fracture network that occurs within siliciclastic rocks of the lowermost Siccar Point group, Gale crater, Mars. The Siccar Point group is exposed over approximately 20 km2 in northwest Gale crater, where it unconformably overlies eroded strata of Mount Sharp (Aeolis Mons) and reflects likely aeolian deposition along the lower flanks of Mount Sharp. Images reveal an extensive network of erosionally resistant polygons, approximately 7.5 m across, that exhibit interior angles (i.e., fracture intersections) with modes at 90° and 120°. Polygon morphology indicates that fractures formed during multiple cycles of expansion and contraction, which is attributed to desiccation and subsequent recharge of near‐surface groundwater. The erosional resistance of preserved fractures is inferred to reflect postfracture diagenetic fluid flow along the sub–Siccar Point group unconformity and cementation. Evidence for multiple fluid events in the relatively young strata of the Siccar Point group requires a protracted history of fluid stability in Gale crater.
Chlorate as a Potential Oxidant on Mars: Rates and Products of Dissolved Fe(II) Oxidation
Authors: Mitra Kaushik , Catalano Jeffrey G. 
Published: October 2019

AbstractOxychlorine species are globally widespread across the Martian surface. Despite their ubiquitous presence, the ability of oxychlorine species to serve as oxidants on Mars has largely been unexplored. While perchlorate is kinetically inert, chlorate may be a critical Fe(II) oxidant on Mars. However, the timescale over which chlorate may oxidize Fe(II) and the mineral products formed in Mars‐relevant fluids are unclear. Fe(II) oxidation by chlorate was thus investigated in magnesium chloride, sulfate, and perchlorate fluids under neutral to acidic conditions for different total Fe(II) and background salt concentrations. The results show near‐complete Fe(II) oxidation within approximately 2 to 4 weeks, accompanied by formation of the Fe(III) minerals goethite, lepidocrocite, akaganeite, and jarosite. The Fe(II) oxidation rate and the mineral products depend on Fe(II) concentration, the composition and concentration of the background salt, and the acidity of the solution. Calibration of an existing rate law to lower temperatures well reproduces the observed oxidation kinetics in all fluid compositions and allows prediction of the rate of Fe(II) oxidation by chlorate under diverse Mars‐relevant conditions. Rate comparisons demonstrates that chlorate can oxidize Fe(II) substantially faster than O2and on similar or shorter timescales than ultraviolet light. Notably, chlorate causes rapid oxidation under acidic conditions, unlike other oxidants. Chlorate may thus represent an important abiotic Fe(II) oxidant on Mars. The expected coassociation of chlorate with perchlorate may allow for its percolation into the subsurface during brine migration, leading to oxidation in regions that are cutoff from ultraviolet radiation and atmospherically derived oxidants.
Intelligent metasurface imager and recognizer
Authors: Li Lianlin , Shuang Ya , Ma Qian , Li Haoyang , Zhao Hanting , Wei Menglin , Liu Che , Hao Chenglong , Qiu Cheng-Wei , Cui Tie Jun 
Published: October 2019

AbstractThere is an increasing need to remotely monitor people in daily life using radio-frequency probe signals. However, conventional systems can hardly be deployed in real-world settings since they typically require objects to either deliberately cooperate or carry a wireless active device or identification tag. To accomplish complicated successive tasks using a single device in real time, we propose the simultaneous use of a smart metasurface imager and recognizer, empowered by a network of artificial neural networks (ANNs) for adaptively controlling data flow. Here, three ANNs are employed in an integrated hierarchy, transforming measured microwave data into images of the whole human body, classifying specifically designated spots (hand and chest) within the whole image, and recognizing human hand signs instantly at a Wi-Fi frequency of 2.4 GHz. Instantaneous in situ full-scene imaging and adaptive recognition of hand signs and vital signs of multiple non-cooperative people were experimentally demonstrated. We also show that the proposed intelligent metasurface system works well even when it is passively excited by stray Wi-Fi signals that ubiquitously exist in our daily lives. The reported strategy could open up a new avenue for future smart cities, smart homes, human-device interaction interfaces, health monitoring, and safety screening free of visual privacy issues.
Distinct nitrogen cycling and steep chemical gradients in Trichodesmium colonies
Authors: Klawonn Isabell , Eichner Meri J , Wilson Samuel T , Moradi Nasrollah , Thamdrup Bo , Kümmel Steffen , Gehre Matthias , Khalili Arzhang , Grossart Hans-Peter , Karl David M , Ploug Helle 
Published: October 2019

Abstract
Trichodesmium is an important dinitrogen (N2)-fixing cyanobacterium in marine ecosystems. Recent nucleic acid analyses indicate that Trichodesmium colonies with their diverse epibionts support various nitrogen (N) transformations beyond N2 fixation. However, rates of these transformations and concentration gradients of N compounds in Trichodesmium colonies remain largely unresolved. We combined isotope-tracer incubations, micro-profiling and numeric modelling to explore carbon fixation, N cycling processes as well as oxygen, ammonium and nitrate concentration gradients in individual field-sampled Trichodesmium colonies. Colonies were net-autotrophic, with carbon and N2 fixation occurring mostly during the day. Ten percent of the fixed N was released as ammonium after 12-h incubations. Nitrification was not detectable but nitrate consumption was high when nitrate was added. The consumed nitrate was partly reduced to ammonium, while denitrification was insignificant. Thus, the potential N transformation network was characterised by fixed N gain and recycling processes rather than denitrification. Oxygen concentrations within colonies were ~60–200% air-saturation. Moreover, our modelling predicted steep concentration gradients, with up to 6-fold higher ammonium concentrations, and nitrate depletion in the colony centre compared to the ambient seawater. These gradients created a chemically heterogeneous microenvironment, presumably facilitating diverse microbial metabolisms in millimetre-sized Trichodesmium colonies.
Transient exposure to novel high temperatures reshapes coastal phytoplankton communities
Authors: Kling Joshua D , Lee Michael D , Fu Feixue , Phan Megan D , Wang Xinwei , Qu Pingping , Hutchins David A 
Published: October 2019

Abstract
Average sea surface temperatures are expected to rise 4° this century, and marine phytoplankton and bacterial community composition, biogeochemical rates, and trophic interactions are all expected to change in a future warmer ocean. Thermal experiments typically use constant temperatures; however, weather and hydrography cause marine temperatures to fluctuate on diel cycles and over multiple days. We incubated natural communities of phytoplankton collected from California coastal waters during spring, summer, and fall under present-day and future mean temperatures, using thermal treatments that were either constant or fluctuated on a 48 h cycle. As assayed by marker-gene sequencing, the emergent microbial communities were consistent within each season, except when culture temperatures exceeded the highest temperature recorded in a 10-year local thermal dataset. When temperature treatments exceeded the 10-year maximum the phytoplankton community shifted, becoming dominated by diatom amplicon sequence variants (ASVs) not seen at lower temperatures. When mean temperatures were above the 10-year maximum, constant and fluctuating regimes each selected for different ASVs. These findings suggest coastal microbial communities are largely adapted to the current range of temperatures they experience. They also suggest a general hypothesis whereby multiyear upper temperature limits may represent thresholds, beyond which large community restructurings may occur. Now inevitable future temperature increases that exceed these environmental thresholds, even temporarily, may fundamentally reshape marine microbial communities and therefore the biogeochemical cycles that they mediate.
Abnormalities of confidence in psychiatry: an overview and future perspectives
Authors: Hoven Monja , Lebreton Maël , Engelmann Jan B. , Denys Damiaan , Luigjes Judy , van Holst Ruth J. 
Published: October 2019

AbstractOur behavior is constantly accompanied by a sense of confidence and its’ precision is critical for adequate adaptation and survival. Importantly, abnormal confidence judgments that do not reflect reality may play a crucial role in pathological decision-making typically seen in psychiatric disorders. In this review, we propose abnormalities of confidence as a new model of interpreting psychiatric symptoms. We hypothesize a dysfunction of confidence at the root of psychiatric symptoms either expressed subclinically in the general population or clinically in the patient population. Our review reveals a robust association between confidence abnormalities and psychiatric symptomatology. Confidence abnormalities are present in subclinical/prodromal phases of psychiatric disorders, show a positive relationship with symptom severity, and appear to normalize after recovery. In the reviewed literature, the strongest evidence was found for a decline in confidence in (sub)clinical OCD, and for a decrease in confidence discrimination in (sub)clinical schizophrenia. We found suggestive evidence for increased/decreased confidence in addiction and depression/anxiety, respectively. Confidence abnormalities may help to understand underlying psychopathological substrates across disorders, and should thus be considered transdiagnostically. This review provides clear evidence for confidence abnormalities in different psychiatric disorders, identifies current knowledge gaps and supplies suggestions for future avenues. As such, it may guide future translational research into the underlying processes governing these abnormalities, as well as future interventions to restore them.
Maternal valproic acid exposure leads to neurogenesis defects and autism-like behaviors in non-human primates
Authors: Zhao Hui , Wang Qiqi , Yan Ting , Zhang Yu , Xu Hui-juan , Yu Hao-peng , Tu Zhuchi , Guo Xiangyu , Jiang Yong-hui , Li Xiao-jiang , Zhou Huihui , Zhang Yong Q. 
Published: October 2019

AbstractDespite the substantial progress made in identifying genetic defects in autism spectrum disorder (ASD), the etiology for majority of ASD individuals remains elusive. Maternal exposure to valproic acid (VPA), a commonly prescribed antiepileptic drug during pregnancy in human, has long been considered a risk factor to contribute to ASD susceptibility in offspring from epidemiological studies in humans. The similar exposures in murine models have provided tentative evidence to support the finding from human epidemiology. However, the apparent difference between rodent and human poses a significant challenge to extrapolate the findings from rodent models to humans. Here we report for the first time the neurodevelopmental and behavioral outcomes of maternal VPA exposure in non-human primates. Monkey offspring from the early maternal VPA exposure have significantly reduced NeuN-positive mature neurons in prefrontal cortex (PFC) and cerebellum and the Ki67-positive proliferating neuronal precursors in the cerebellar external granular layer, but increased GFAP-positive astrocytes in PFC. Transcriptome analyses revealed that maternal VPA exposure disrupted the expression of genes associated with neurodevelopment in embryonic brain in offspring. VPA-exposed juvenile offspring have variable presentations of impaired social interaction, pronounced stereotypies, and more attention on nonsocial stimuli by eye tracking analysis. Our findings in non-human primates provide the best evidence so far to support causal link between maternal VPA exposure and neurodevelopmental defects and ASD susceptibility in humans.
Ultrahigh resolution and color gamut with scattering-reducing transmissive pixels
Authors: Lee June Sang , Park Ji Yeon , Kim Yong Hwan , Jeon Seokwoo , Ouellette Olivier , Sargent Edward H. , Kim Dong Ha , Hyun Jerome K. 
Published: October 2019

AbstractWhile plasmonic designs have dominated recent trends in structural color, schemes using localized surface plasmon resonances and surface plasmon polaritons that simultaneously achieve high color vibrancy at ultrahigh resolution have been elusive because of tradeoffs between size and performance. Herein we demonstrate vibrant and size-invariant transmissive type multicolor pixels composed of hybrid TiOx-Ag core-shell nanowires based on reduced scattering at their electric dipolar Mie resonances. This principle permits the hybrid nanoresonator to achieve the widest color gamut (~74% sRGB area coverage), linear color mixing, and the highest reported single color dots-per-inch (58,000~141,000) in transmission mode. Exploiting such features, we further show that an assembly of distinct nanoresonators can constitute a multicolor pixel for use in multispectral imaging, with a size that is ~10-folds below the Nyquist limit using a typical high NA objective lens.
Genotypic performance of Australian durum under single and combined water-deficit and heat stress during reproduction
Authors: Liu Haipei , Able Amanda J. , Able Jason A. 
Published: October 2019

AbstractIn Mediterranean environments, water deficiency and heat during reproduction severely limit cereal crop production. Our research investigated the effects of single and combined pre-anthesis water-deficit stress and post-anthesis heat stress in ten Australian durum genotypes, providing a systematic evaluation of stress response at the molecular, physiological, grain quality and yield level. We studied leaf physiological traits at different reproductive stages, evaluated the grain yield and quality, and the associations among them. We profiled the expression dynamics of two durum microRNAs and their protein-coding targets (auxin response factors and heat shock proteins) involved in stress adaptation. Chlorophyll content, stomatal conductance and leaf relative water content were mostly reduced under stress, however, subject to the time-point and genotype. The influence of stress on grain traits (e.g., protein content) also varied considerably among the genotypes. Significant positive correlations between the physiological traits and the yield components could be used to develop screening strategies for stress improvement in breeding. Different expression patterns of stress-responsive microRNAs and their targets in the most stress-tolerant and most stress-sensitive genotype provided some insight into the complex defense molecular networks in durum. Overall, genotypic performance observed indicates that different stress-coping strategies are deployed by varieties under various stresses.
Molecular dissection of resistance gene cluster and candidate gene identification of Pl17 and Pl19 in sunflower by whole-genome resequencing
Authors: Ma Guojia , Song Qijian , Underwood William R. , Zhang Zhiwei , Fiedler Jason D. , Li Xuehui , Qi Lili 
Published: October 2019

AbstractSunflower (Helianthus annuus L.) production is challenged by different biotic and abiotic stresses, among which downy mildew (DM) is a severe biotic stress that is detrimental to sunflower yield and quality in many sunflower-growing regions worldwide. Resistance against its infestation in sunflower is commonly regulated by single dominant genes. Pl17 and Pl19 are two broad-spectrum DM resistance genes that have been previously mapped to a gene cluster spanning a 3.2 Mb region at the upper end of sunflower chromosome 4. Using a whole-genome resequencing approach combined with a reference sequence-based chromosome walking strategy and high-density mapping populations, we narrowed down Pl17 to a 15-kb region flanked by SNP markers C4_5711524 and SPB0001. A prospective candidate gene HanXRQChr04g0095641 for Pl17 was identified, encoding a typical TNL resistance gene protein. Pl19 was delimited to a 35-kb region and was approximately 1 Mb away from Pl17, flanked by SNP markers C4_6676629 and C4_6711381. The only gene present within the delineated Pl19 locus in the reference genome, HanXRQChr04g0095951, was predicted to encode an RNA methyltransferase family protein. Six and eight SNP markers diagnostic for Pl17 and Pl19, respectively, were identified upon evaluation of 96 diverse sunflower lines, providing a very useful tool for marker-assisted selection in sunflower breeding programs.
Seed Priming with Melatonin Improves the Seed Germination of Waxy Maize under Chilling Stress via Promoting the Antioxidant System and Starch Metabolism
Authors: Cao Qingjun , Li Gang , Cui Zhengguo , Yang Fentuan , Jiang Xiaoli , Diallo Lamine , Kong Fanli 
Published: October 2019

AbstractChilling stress is one of the major abiotic stresses affecting waxy maize plant growth. Melatonin (MT) is able to improve tolerance to abiotic stress in plants. To investigate the effects of seed priming with MT on tolerance to chilling stress in waxy maize, the seed germination characteristics and physiological parameters were tested with varied MT concentrations (0, 50, 100 µM) and treatment times (12, 24 h) at ambient (25 °C) and chilling (13 °C) temperature. MT primed seeds significantly enhanced the germination potential (by 20.29% and 50.71%, respectively), germination rate (by 20.88% and 33.72%), and increased the radicle length (by 90.73% and 217.14%), hypocotyl length (by 60.28% and 136.14%), root length (by 74.59% and 108.70%), and seed vigor index (46.13%, 63.81%), compared with the non-priming seeds under chilling stress. No significant difference was found in priming time between primed and non-primed seeds. In addition, lower H2O2 and malondialdehyde concentrations, increased antioxidant enzyme activities (superoxide dismutase, peroxidase, catalase and ascorbateperoxidase), and promoted starch metabolism were found in primed seeds compared to non-primed ones. It was suggested that seed priming with MT improved waxy maize seed germination under chilling stress through improving antioxidant system and starch metabolism, which protected from oxidative damage.
Metal ions and redox balance regulate distinct amyloid-like aggregation pathways of GAPR-1
Authors: Sheng Jie , Olrichs Nick K. , Geerts Willie J. , Kaloyanova Dora V. , Helms J. Bernd 
Published: October 2019

AbstractMembers of the CAP superfamily (Cysteine-rich secretory proteins, Antigen 5, and Pathogenesis-Related 1 proteins) are characterized by the presence of a structurally conserved CAP domain. The common structure-function relationship of this domain is still poorly understood. In this study, we unravel specific molecular mechanisms modulating the quaternary structure of the mammalian CAP protein GAPR-1 (Golgi-Associated plant Pathogenesis-Related protein 1). Copper ions are shown to induce a distinct amyloid-like aggregation pathway of GAPR-1 in the presence of heparin. This involves an immediate shift from native multimers to monomers which are prone to form amyloid-like fibrils. The Cu2+-induced aggregation pathway is independent of a conserved metal-binding site and involves the formation of disulfide bonds during the nucleation process. The elongation process occurs independently of the presence of Cu2+ ions, and amyloid-like aggregation can proceed under oxidative conditions. In contrast, the Zn2+-dependent aggregation pathway was found to be independent of cysteines and was reversible upon removal of Zn2+ ions. Together, our results provide insight into the regulation of the quaternary structure of GAPR-1 by metal ions and redox homeostasis with potential implications for regulatory mechanisms of other CAP proteins.