Nickel-catalyzed transformation of alkene-tethered oxime ethers to nitriles using a traceless directing group strategy has been developed. A series of alkene-tethered oxime ethers derived from ...benzaldehyde and cinnamyl aldehyde derivatives were converted into the corresponding benzonitriles and cinnamonitriles in 46–98% yields using the nickel catalyst system. Control experiments showed that the alkene group tethered to an oxygen atom on the oximes via one methylene unit plays a key role as a traceless directing group during the catalysis.
The horizontal spectrum of wind variance, conventionally referred to as the kinetic energy spectrum, is examined in experiments conducted with the Atmospheric GCM for the Earth Simulator (AFES) ...global spectral general circulation model. We find that the control version of AFES run at T639 horizontal spectral resolution simulates a kinetic energy spectrum that compares well at large scales with global observational reanalyses and, at smaller scales, with available aircraft observations at near‐tropopause levels. Specifically there is a roughly −3 power‐law dependence on horizontal wave number for wavelengths between about 5000 and 500 km, transitioning to a shallower mesoscale regime at smaller wavelengths. This is seen for both one‐dimensional spectra and for the two‐dimensional total wave number spectrum based on a spherical harmonic analysis. The simulated spectrum at midtropospheric levels is similar in that there is a transition to a shallower mesoscale regime, but the spectrum in the mesoscale is clearly steeper at midtroposphere than near the tropopause. There seem to be no extensive observations of horizontal spectra available in the midtroposphere, so it is not known whether the contrast seen in the model between upper and mid tropospheric levels is realistic. The dependence of the model simulated variability on the subgrid‐scale moist convection parameterization is examined. The space‐time variability of rainfall is shown to depend strongly on the convection scheme employed. The tropospheric kinetic energy spectrum in the mesoscale seems to be correlated with the precipitation behavior, so that in a version with a more variable precipitation field the kinetic energy in the mesoscale is enhanced. This suggests that the mesoscale motions in the model may be directly forced to a significant extent by the variability in the latent heating field. Experiments were also performed with a dry dynamical core version of the model run at both T639 and T1279 resolutions. This version also simulated a shallow mesoscale range, supporting the view that the mesoscale regime in the atmosphere is energized, at least in part, by a predominantly forward (i.e., downscale) nonlinear spectral cascade. Experiments with various formulations of the hyperdiffusion horizontal mixing parameterization show that the kinetic energy spectrum over about the last half of the resolved wave number range is under strong control by the parameterized mixing. However, the T1279 model simulates almost a decade of the shallow mesoscale regime (i.e., for horizontal wavelengths from about 80 to 500 km) that appears to be fairly independent of the diffusion employed. Finally, experiments are conducted in the dry version to see the effects on the kinetic energy spectrum of changing the thermal Rossby number for the simulations.
The existence of liquid water within an oxidized environment on early Mars has been inferred by the Mn-rich rocks found during recent explorations on Mars. The oxidized atmosphere implied by the ...Mn-rich rocks would basically be comprised of CO2 and H2O without any reduced greenhouse gases such as H2 and CH4. So far, however, it has been thought that early Mars could not have been warm enough to sustain water in liquid form without the presence of reduced greenhouse gases. Here, we propose that H2O2 could have been the gas responsible for warming the surface of the oxidized early Mars. Our one-dimensional atmospheric model shows that only 1 ppm of H2O2 is enough to warm the planetary surface because of its strong absorption at far-infrared wavelengths, in which the surface temperature could have reached over 273 K for a CO2 atmosphere with a pressure of 3 bar. A wet and oxidized atmosphere is expected to maintain sufficient quantities of H2O2 gas in its upper atmosphere due to its rapid photochemical production in slow condensation conditions. Our results demonstrate that a warm and wet environment could have been maintained on an oxidized early Mars, thereby suggesting that there may be connections between its ancient atmospheric redox state and possible aqueous environment.
Neuroblastoma, a type of cancer that is common in children, is composed of two genetically clonal but epigenetically distinct cell types: mesenchymal (MES) and adrenergic (ADRN) types, controlled by ...super‐enhancer‐associated lineage‐specific transcription factor networks. Mesenchymal‐type cells are more migratory, resistant to chemotherapy, and prevalent in relapse tumors. Importantly, both cell types spontaneously transdifferentiate into one another, and this interconversion can be induced by genetic manipulations. However, the mechanisms of their spontaneous transdifferentiation and extracellular factors inducing this phenomenon have not yet been elucidated. Using a unique approach involving gene set enrichment analysis, we selected six ADRN and 10 MES candidate factors, possibly inducing ADRN and MES phenotypes, respectively. Treatment with a combination of 10 MES factors clearly induced the MES gene expression profile in ADRN‐type SH‐SY5Y neuroblastoma cells. Considering the effects on gene expression profile, migration ability, and chemoresistance, a combination of tumor necrosis factor alpha (TNF‐α) and epidermal growth factor (EGF) was sufficient to synergistically induce the ADRN‐to‐MES transdifferentiation in SH‐SY5Y cells. In addition, human neuroblastoma cohort analysis revealed that the expression of TNF and EGF receptors was strongly associated with MES gene expression signatures, supporting their important roles in transdifferentiation in vivo. Collectively, we propose a mechanism of neuroblastoma transdifferentiation induced by extracellular growth factors, which can be controlled in clinical situations, providing a new therapeutic possibility.
Neuroblastoma is composed of two epigenetically controlled cell types, mesenchymal (MES) and adrenergic (ADRN) types, which spontaneously transdifferentiate into one another. We found a synergistic combination of tumor necrosis factor and epidermal growth factor that induced the transdifferentiation from ADRN to MES state in ADRN‐type SH‐SY5Y neuroblastoma cells.
Cloud patterns are important clues for revealing the atmospheric circulation of Venus. Recently, a planetary-scale streak structure has been discovered in middle- and lower-cloud images of Venus' ...night-side taken by IR2, the 2-μm camera, on board the Akatsuki orbiter. However, its formation mechanism has not been investigated. Here we succeed, for the first time, in reproducing the patterns of the observed streak structure, as regions of strong downward flows that develop in high-resolution global simulations of the Venus atmosphere. The streaks are formed in both hemispheres with equatorial symmetry, which is caused by equatorial Rossby-like and Kelvin-like waves with zonal wavenumber one. The low-stability layer that has been suggested by past observations is essential for reproducing the streak structure. The streaks of downward flow result from the interaction of the meridionally tilted phase lines of the Rossby-like waves and the characteristics of baroclinic instability produced around the low-stability layer.
We investigated whether the inferior parietal lobule (IPL) responds in real-time to multisensory inconsistency during movement. The IPL is thought to be involved in both the detection of ...inconsistencies in multisensory information obtained during movement and that obtained during self-other discrimination. However, because of the limited temporal resolution of conventional neuroimaging techniques, it is difficult to distinguish IPL activity during movement from that during self-other discrimination. We simultaneously conducted electroencephalography (EEG) and near-infrared spectroscopy (NIRS) with the goal of examining IPL activity with a high spatiotemporal resolution during single reaching movements. Under a visual feedback-delay condition, gamma event-related synchronization (γ-ERS), i.e., an increase in gamma (31–47 Hz) EEG power, occurred during reaching movements. This γ-ERS is considered to reflect processing of information about prediction errors. To integrate this temporal information with spatial information from the NIRS signals, we developed a new analysis technique that enabled estimation of the regions that show a hemodynamic response characterized by EEG fluctuation present in the visual feedback-delay condition. As a result, IPL activity was explained by γ-ERS specific to visual feedback delay during movements. Thus, we succeeded in demonstrating real-time activation of the IPL in response to multisensory inconsistency. However, we did not find any correlation between either IPL activity or γ-ERS with the sense of agency. Therefore, our results suggest that while the IPL is influenced by prediction error signals, it does not engage in direct processing underlying the conscious experience of making a movement, which is the foundation of self-other discrimination.
•CH4 fluxes were observed by chambers in an upland forest soil over seven years.•Modules for CH4 uptake were calibrated by the observed data with a Bayesian method.•After calibrating two parameters, ...the modules reproduced the observed fluxes well.•Future CH4 fluxes were predicted to increase with rising CH4 concentrations.•The modules contained high uncertainty levels in future predictions even after the calibration.
Upland soils are thought to be a sink of CH4, the second most important anthropogenic greenhouse gas, owing to oxidation by methanotrophs. To better understand CH4 fluxes in upland forests, we quasi-continuously measured CH4 fluxes using an automated closed chamber system over seven years on a larch plantation in a volcanic soil in Japan. We hypothesized that the long-term data sufficiently can calibrate modules for CH4 fluxes, and aimed to predict future pathways of CH4 uptake and their uncertainties in the forest. Based on the observations, a thinning of the overstory only marginally influenced the CH4 fluxes measured by the chambers. Using the data with a Bayesian method, we calibrated four modules for CH4 fluxes in forest soils, which were embedded in the process-based ecosystem model VISIT. The modules well reproduced the observed seasonality, annual budgets, and interannual variability in the CH4 fluxes after calibrating the following parameters: the diffusion coefficient or base CH4 oxidation rate constant and temperature sensitivity. The CH4 fluxes were predicted to increase in the future under the RCP8.5 scenario but to decrease under the RCP 2.6 scenario. The contrasting trajectory was caused by rising and decreasing CH4 concentrations under the RCP 8.5 and 2.6 scenarios, respectively. Furthermore, the magnitudes of the future changes in the fluxes differed in each module because the responses to the changes in the CH4 concentrations were inconsistent among the modules. The observed CH4 fluxes increased with increasing atmospheric CH4 concentration (4.95 mg CH4 m−2 d−1 ppm−1), which was greater in magnitude than those in the modules. Considering the uncertainties in the modules and potential confounding effects in the observations, we conclude that further understanding the responses of CH4 uptake to rising CH4 concentrations is required.
Somatic mutations in MYCN have been identified across various tumors, playing pivotal roles in tumorigenesis, tumor progression, and unfavorable prognoses. Despite its established notoriety as an ...oncogenic driver, there is a growing interest in exploring the involvement of MYCN in human development. While MYCN variants have traditionally been associated with Feingold syndrome type 1, recent discoveries highlight gain-of-function variants, specifically p.(Thr58Met) and p.(Pro60Leu), as the cause for megalencephaly-polydactyly syndrome. The elucidation of cellular and murine analytical data from both loss-of-function (Feingold syndrome model) and gain-of-function models (megalencephaly-polydactyly syndrome model) is significantly contributing to a comprehensive understanding of the physiological role of MYCN in human development and pathogenesis. This review discusses the MYCN’s functional implications for human development by reviewing the clinical characteristics of these distinct syndromes, Feingold syndrome, and megalencephaly-polydactyly syndrome, providing valuable insights into the understanding of pathophysiological backgrounds of other syndromes associated with the MYCN pathway and the overall comprehension of MYCN’s role in human development.
Direct-imaging techniques of exoplanets have made significant progress recently and will eventually enable monitoring of photometric and spectroscopic signals of Earth-like habitable planets. The ...presence of clouds, however, would remain as one of the most uncertain components in deciphering such direct-imaged signals of planets. We attempt to examine how the planetary obliquity produces different cloud patterns by performing a series of general circulation model simulation runs using a set of parameters relevant for our Earth. Then we use the simulated photometric lightcurves to compute their frequency modulation that is due to the planetary spin-orbit coupling over an entire orbital period, and we attempt to see to what extent one can estimate the obliquity of an Earth twin. We find that it is possible to estimate the obliquity of an Earth twin within the uncertainty of several degrees with a dedicated 4 m space telescope at 10 pc away from the system if the stellar flux is completely blocked. While our conclusion is based on several idealized assumptions, a frequency modulation of a directly imaged Earth-like planet offers a unique methodology to determine its obliquity.
•Soil temperature strongly affected understory CO2 effluxes.•Spring soil temperature strongly affected inter-annual variations of the effluxes.•The influence of soil moisture on the fluxes was minor, ...except during a dry summer.•Understory photosynthesis increased after canopy disturbance by a typhoon.•Understory CO2 efflux is likely to increase under a future warmer environment.
To understand climate change’s effect on understory CO2 flux components, we established automated chambers in a 56-year-old Japanese larch (Larix kaempferi Sarg.) forest in central Japan for long-term continuous measurements. Between 2006 and 2013, annual CO2 fluxes ranged from 7.0 to 8.4tCha−1yr−1 for soil respiration (Rs), 5.7–6.8tCha−1yr−1 for heterotrophic respiration (Rh), 9.3–10.7tCha−1yr−1 for total understory respiration (Ru), 2.6–3.5tCha−1yr−1 for understory gross primary production (GPPu), and 6.1–7.6tCha−1yr−1 for net understory CO2 exchange (NUE). Mean annual soil temperature (MATs), especially in spring, was positively related to annual Rs, Rh, Ru, and NUE. Based on the inter-annual relationship between MATs and annual understory CO2 effluxes, a 1°C MATs increase was estimated to increase annual effluxes by 25.1% for Rs and Rh, 14.4% for Ru, and 23.9% for NUE. The growing season CO2 flux components were weakly associated with soil moisture. However, during a short dry period in the summer of 2013, we observed a strong relationship between soil moisture and understory Rs, Rh, and Ru. GPPu was primarily controlled by the understory light intensity; GPPu during growing season increased where the canopy was disturbed by typhoons in the early growing seasons in 2007 (+9.8%) and 2012 (+24.4%) as well as during the 2013 growing season (+12.2%) due to a short drought. Understory CO2 effluxes in this larch forest will likely increase under global warming.
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