South Asia experienced a weakening of summer monsoon circulation in the past several decades, resulting in rainfall decline in wet regions. In comparison with other tropical ecosystems, quantitative ...assessments of the extent and triggers of vegetation change are lacking in assessing climate‐change impacts over South Asia dominated by crops. Here, we use satellite‐based Normalized Difference Vegetation Index (NDVI) to quantify spatial–temporal changes in vegetation greenness, and find a widespread annual greening trend that stands in contrast to the weakening of summer monsoon circulation particularly over the last decade. We further show that moisture supply is the primary factor limiting vegetation activity during dry season or in dry region, and cloud cover or temperature would become increasingly important in wet region. Enhanced moisture conditions over dry region, coinciding with the decline in monsoon, are mainly responsible for the widespread greening trend. This result thereby cautions the use of a unified monsoon index to predict South Asia's vegetation dynamics. Current climate–carbon models in general correctly reproduce the dominant control of moisture in the temporal characteristics of vegetation productivity. But the model ensemble cannot exactly reproduce the spatial pattern of satellite‐based vegetation change mainly because of biases in climate simulations. The moisture‐induced greening over South Asia, which is likely to persist into the wetter future, has significant implications for regional carbon cycling and maintaining food security.
Spatial distributions of GIMMS NDVI trends over the South Asia during the three periods: 1982–2014 (first row), 1982–2001 (second row), and 2002–2014 (third row). The trends are estimated on the annual (a, d, and g), wet season (b, e, and h), and dry season basis (c, f, and i), respectively. The inset panels show the pixels where NDVI trends are statistically significant at p < .05.
Hypoxia-inducible factor 1α (HIF-1α) is essential in hepatocellular carcinoma (HCC) glycolysis and progression. Yes-associated protein (YAP) is a powerful regulator and is overexpressed in many ...cancers, including HCC. The regulatory mechanism of YAP and HIF-1α in HCC glycolysis is unknown.
We detected YAP expression in 54 matched HCC tissues and the adjacent noncancerous tissues. The relationship between YAP mRNA expression and that of HIF-1α was analyzed using The Cancer Genome Atlas HCC tissue data. We cultured HepG2 and Huh7 HCC cells under normoxic (20% O
) and hypoxic (1% O
) conditions, and measured the lactate and glucose levels, migration and invasive capability, and the molecular mechanism of HCC cell glycolysis and progression.
In this study, we detected YAP expression in 54 matched HCC tissues and the adjacent noncancerous tissues. We observed that hypoxia-induced YAP activation is crucial for accelerating HCC cell glycolysis. Hypoxia inhibited the Hippo signaling pathway and promoted YAP nuclear localization, and decreased phosphorylated YAP expression in HCC cells. YAP knockdown inhibited HCC cell glycolysis under hypoxic. Mechanistically, hypoxic stress in the HCC cells promoted YAP binding to HIF-1α in the nucleus and sustained HIF-1α protein stability to bind to PKM2 gene and directly activates PKM2 transcription to accelerate glycolysis.
Our findings describe a new regulatory mechanism of hypoxia-mediated HCC metabolism, and YAP might be a promising therapeutic target in HCC.
Considering the application of cryogenic treatment in aerospace manufacturing field, the hot rolled 7055 Al–Zn–Mg–Cu alloy thick plate was selected in order to solve its mechanical anisotropy. ...Several cryogenic-aging processes were applied by introducing deep cryogenic treatment, pre-deformation and natural aging as pre-treatments and two-stage artificial aging as final treatment. An optimized artificial aging parameter in this paper is 110 °C/6 h + 130 °C/16 h, for a best preformance (Rm-max = 668 Mpa, Rp0.2-max = 635 Mpa, A25mm-max = 8.52%) in transverse direction. Nearly all the samples pre-treated by various cryogenic processes obtain stable plastic deformation capacity. Generally, there exist geometric recrystallization, continuous recrystallizaion and discontinuous recrystallization, to some extent in different period of cryogenic-aging process. The final morphology is the result of a mutual compromise between pinning effect originated from cryogenic or natural aging precipitates and recrystallization driving force originating from the energy stored in cryogenic or pre-tensile deformed microstructure. For the thick plate of hot-rolled AA7055, the pair of original rolling Brass components can be enhanced by cryogenic treatment or compressive deformation along transverse direction. But the final texture and the morphology of Σ3n GBs are affected mainly in artificial stage due to various abilities of recovery and discontinuous recrystallization in different directions. Tensile plastic deformation and cycled cryogenic treatment can destroy the Brass components, together with continuous straight geometrically necessary boundaries, more effectively. Since precipitation is probablely accelerated through pre-treatments, a modification of artificial aging time has promising prospect to achieve more excellent mechanical performance.
The epidermal growth factor receptor (EGFR) plays a pivotal role in cancer therapeutics, with small-molecule EGFR inhibitors emerging as significant agents in combating this disease. This review ...explores the synthesis and clinical utilization of EGFR inhibitors, starting with the indispensable role of EGFR in oncogenesis and emphasizing the intricate molecular aspects of the EGFR-signaling pathway. It subsequently provides information on the structural characteristics of representative small-molecule EGFR inhibitors in the clinic. The synthetic methods and associated challenges pertaining to these compounds are thoroughly examined, along with innovative strategies to overcome these obstacles. Furthermore, the review discusses the clinical applications of FDA-approved EGFR inhibitors such as erlotinib, gefitinib, afatinib, and osimertinib across various cancer types and their corresponding clinical outcomes. Additionally, it addresses the emergence of resistance mechanisms and potential counterstrategies. Taken together, this review aims to provide valuable insights for researchers, clinicians, and pharmaceutical scientists interested in comprehending the current landscape of small-molecule EGFR inhibitors.
Hexagonal boron nitride (hBN) is a remarkable two-dimensional (2D) material that hosts solid-state spins and has great potential to be used in quantum information applications, including quantum ...networks. However, in this application, both the optical and spin properties are crucial for single spins but have not yet been discovered simultaneously for hBN spins. Here, we realize an efficient method for arraying and isolating the single defects of hBN and use this method to discover a new spin defect with a high probability of 85%. This single defect exhibits outstanding optical properties and an optically controllable spin, as indicated by the observed significant Rabi oscillation and Hahn echo experiments at room temperature. First principles calculations indicate that complexes of carbon and oxygen dopants may be the origin of the single spin defects. This provides a possibility for further addressing spins that can be optically controlled.
Accurate cotton maps are crucial for monitoring cotton growth and precision management. The paper proposed a county-scale cotton mapping method by using random forest (RF) feature selection algorithm ...and classifier based on selecting multi-features, including spectral, vegetation indices, and texture features. The contribution of texture features to cotton classification accuracy was also explored in addition to spectral features and vegetation index. In addition, the optimal classification time, feature importance, and the best classifier on the cotton extraction accuracy were evaluated. The results showed that the texture feature named the gray level co-occurrence matrix (GLCM) is effective for improving classification accuracy, ranking second in contribution among all studied spectral, VI, and texture features. Among the three classifiers, the RF showed higher accuracy and better stability than support vector machines (SVM) and artificial neural networks (ANN). The average overall accuracy (OA) of the classification combining multiple features was 93.36%, 7.33% higher than the average OA of the single-time spectrum, and 2.05% higher than the average OA of the multi-time spectrum. The classification accuracy after feature selection by RF can still reach 92.12%, showing high accuracy and efficiency. Combining multiple features and random forest methods may be a promising county-scale cotton classification method.
Mesocotyl is the crucial organ for pushing buds out of deep water or soil after germination in monocots. Deep direct seeding or mechanized dry seeding cultivation practice requires rice cultivars ...having long mesocotyl. However, the mechanisms of mesocotyl elongation and domestication remain unknown. Here, our genome-wide association study (GWAS) reveals that natural variations of OsGSK2, a conserved GSK3-like kinase involved in brassinosteroid signaling, determine rice mesocotyl length variation. Variations in the coding region of OsGSK2 alter its kinase activity. It is selected for mesocotyl length variation during domestication. Molecular analyses show that brassinosteroid-promoted mesocotyl elongation functions by suppressing the phosphorylation of an U-type cyclin, CYC U2, by OsGSK2. Importantly, the F-box protein D3, a major positive component in strigolactone signaling, can degrade the OsGSK2-phosphorylated CYC U2 to inhibit mesocotyl elongation. Together, these results suggest that OsGSK2 is selected to regulate mesocotyl length by coordinating strigolactone and brassinosteroid signaling during domestication.
Earth system models project that the tropical land carbon sink will decrease in size in response to an increase in warming and drought during this century, probably causing a positive climate ...feedback. But available data are too limited at present to test the predicted changes in the tropical carbon balance in response to climate change. Long-term atmospheric carbon dioxide data provide a global record that integrates the interannual variability of the global carbon balance. Multiple lines of evidence demonstrate that most of this variability originates in the terrestrial biosphere. In particular, the year-to-year variations in the atmospheric carbon dioxide growth rate (CGR) are thought to be the result of fluctuations in the carbon fluxes of tropical land areas. Recently, the response of CGR to tropical climate interannual variability was used to put a constraint on the sensitivity of tropical land carbon to climate change. Here we use the long-term CGR record from Mauna Loa and the South Pole to show that the sensitivity of CGR to tropical temperature interannual variability has increased by a factor of 1.9 ± 0.3 in the past five decades. We find that this sensitivity was greater when tropical land regions experienced drier conditions. This suggests that the sensitivity of CGR to interannual temperature variations is regulated by moisture conditions, even though the direct correlation between CGR and tropical precipitation is weak. We also find that present terrestrial carbon cycle models do not capture the observed enhancement in CGR sensitivity in the past five decades. More realistic model predictions of future carbon cycle and climate feedbacks require a better understanding of the processes driving the response of tropical ecosystems to drought and warming.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Late Mesozoic large-scale crustal extension occurred across the northeastern section of continental Asia, and metamorphic core complexes (MCCs) are the major features in this region. This paper ...presents new zircon U–Pb and Ar–Ar ages of biotite and hornblende for pre- or syn- (mylonitized) and post-kinematic (unmylonitized) intrusions from these MCCs, and attempts to determine the timing of initiation, duration and termination of the mid-lower-crustal ductile extension by integrating with geochronological data from previous studies. These MCCs have similar 40Ar/39Ar biotite and hornblende ages (130 to 110Ma, mainly from 130 to 120Ma), which are interpreted as the cooling ages and represent the timing of the late-stage formation of the MCCs. Zircon U–Pb ages for syn- to post-kinematic intrusions from some MCCs suggest that the mid-lower-crustal extension probably initiated at ca. 150–145Ma with a peak occurring 145–130Ma and continued to 130–120Ma, which is older than that suggested by 40Ar/39Ar ages by 10–20Ma. The early ductile extension most likely initiated in Mongolia and northern China during the Late Jurassic (150–145Ma) at a deeper level, then propagated southwards (140–130Ma), and finally developed throughout the entire continental NE Asia (130–120Ma). Based on the timing and processes of the extension, a geodynamic model and tectonic setting of the destruction of the North China Craton (NCC) are proposed.
► U–Pb zircon ages combined with Ar–Ar ages from MCCs are used to constrain mid-lower-crustal extension in NE Asia. ► The extension initiated at ca. 150–140Ma and reached the peak at 130–120Ma and continuing to 130–120Ma. ► The extension migrated southward. ► The extension is due to post-orogenic collapse of the thickened crust. ► Destruction of NCC was part of the reactivity of whole NE Asia.
This paper presents a 12/8-pole, three-phase, modular-stator hybrid excitation switched reluctance machine (MSHSRM) assisted with permanent magnets (PMs) as well as its design consideration and ...performance evaluation. The basic operating principle is illustrated through a specific form of this machine, and the magnetic equivalent circuit model is built and analyzed. Then, the main parameters of the machine are optimized by the finite-element method. The static magnetic characteristics and dynamic performance of this novel machine are simulated and compared with other two SRMs, one is segmented 12/8 SRM without PM, and the other is the conventional 12/8 SRM with unsegmented structure. Finally, two motor prototypes, including one MSHSRM and one conventional SRM of the same size are manufactured. The static magnetic characteristic and dynamic operation of two motor drives are measured to confirm the predictions. The simulation and experimental results indicate that this MSHSRM has higher power and stronger load capacities than the conventional SRM in whole speed range with higher torque/power density and higher torque per ampere.
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