Browse Articles

Optimization of betulinic and ursolic acids and phenolics extraction from endemic Rosa pisiformis using Box-Behnken design in relation to cytotoxic activities

The return of stagnant slab recorded by intraplate volcanism

Subducted plates often stagnate in the mantle transition zone (MTZ), and the fate of the stagnant slabs is still debatable. They may sink into the lower mantle, or remain partially trapped in the MTZ, but it is uncertain whether they can return to the upper mantle. We report geochemical evidence of late-Miocene (~6 Ma) basalts from, and upper mantle seismic evidence beneath Shuangyashan, an area above the slab tear of the stagnant Pacific plate in eastern Asia, to show how the slab returns to the upper mantle from the MTZ. Remarkably high δ 57 Fe, Gd/Yb and low δ 26 Mg, Ti/Eu, CaO/Al 2 O 3 values of Shuangyashan basalts suggest that the subducted Pacific oceanic crust had been entrained to their upper mantle source. Therefore, the return of oceanic crust from the MTZ to the upper mantle appears to have been driven by upwelling triggered by tearing of the stagnant slab right beneath this area. Meanwhile, local shear splitting measurements reveal a circular pattern of anisotropy in the upper mantle with delay times diminishing toward the slab tear, suggesting that the slab-fragment-bearing upwelling subsequently turned into lateral flows in the upper mantle, and contributed to a wider intraplate magmatism above the stagnant slab. This finding, together with other widespread intraplate volcanism from eastern Asia, extending for approximately 6,000 km, demonstrates that a subduction-induced tear can lead to the destruction and partial return of stagnant slab material, and thus lead to the cycling of subducted crustal materials and the generation of subduction-induced intraplate magmatism.

Bathymetry of the Antarctic continental shelf and ice shelf cavities from circumpolar gravity anomalies and other data

AbstractBathymetry critically influences the intrusion of warm Circumpolar Deep Water onto the continental shelf and under ice shelf cavities in Antarctica, thereby forcing ice melting, grounding line retreat, and sea level rise. We present a novel and comprehensive bathymetry of Antarctica that includes all ice shelf cavities and previously unmeasured continental shelf areas. The new bathymetry is based on a 3D inversion of a circumpolar compilation of gravity anomalies constrained by measurements from the International Bathymetric Chart of the Southern Ocean, BedMachine Antarctica, and discrete seafloor measurements from seismic and ocean robotic probes. Previously unknown troughs with thicker ice shelf cavities are revealed in many parts of Antarctica, especially East Antarctica. The greater depths of troughs on the continental shelf and ice shelf cavities imply that many glaciers are more vulnerable to ocean subsurface warming than previously thought, which may increase the projections of sea level rise from Antarctica.

Metastable state preceding shear zone instability: Implications for earthquake-accelerated landslides and dynamic triggering

Understanding the dynamic response of granular shear zones under cyclic loading is fundamental to elucidating the mechanisms triggering earthquake-induced landslides, with implications for broader fields such as seismology and granular physics. Existing prediction methods struggle to accurately predict many experimental and in situ landslide observations due to inadequate consideration of the underlying physical mechanisms. The mechanisms that influence landslide dynamic triggering, a transition from static (or extremely slow creeping) to rapid runout, remain elusive. Herein, we focus on the inherent physics of granular shear zones under dynamic loading using ring shear experiments. Except for coseismic slip caused by the dynamic load, varying magnitudes of postseismic creep with increasing cycles of dynamic loading are observed, highlighting the effects of coseismic weakening (shear zone fatigue) and subsequent postseismic healing. A metastable state, characterized by a significant increase in postseismic creep, typically precedes shear zone instability. The metastable state may arise as weakened shear resistance approaches the applied shear stress, demonstrating a phase transition from a solid-like state to a fluid state (plastic granular flow). The metastable state may potentially indicate the shear zone’s stress state and serve as a precursor to impending instability. Furthermore, the proposed mechanisms offer a compelling explanation for the widespread postseismic landslide movement following earthquakes. Incorporating these mechanisms into the Newmark method has the potential to improve the prediction of earthquake-induced landslide displacement and enhance our understanding of dynamic triggering.

Genome-wide identification, characterization, and functional analysis of the CHX, SOS, and RLK genes in Solanum lycopersicum under salt stress

Abstract The cation/proton exchanger ( CHX ), salt overly sensitive ( SOS ), and receptor-like kinase ( RLK ) genes play significant roles in the response to salt stress in plants. This study is the first to identify the SOS gene in Solanum lycopersicum (tomato) through genome-wide analysis under salt stress conditions. Quantitative reverse transcription PCR (qRT-PCR) results indicated that the expression levels of CHX , SOS , and RLK genes were upregulated, with fold changes of 1.83, 1.49, and 1.55, respectively, after 12 h of exposure to salt stress. Genome-wide analysis revealed 21 CHX , 5 SOS , and 86 RLK genes in S. lycopersicum . CHX genes were found on chromosomes 2, 3, 4, 5, 6, 7, 8, 9, 11, and 12 of S. lycopersicum . SOS genes were found on chromosomes 1, 4, 6, and 10. RLK genes were found on all chromosomes of S. lycopersicum . The Ka/Ks ratios indicate that the CHX , SOS , and RLK genes have been primarily influenced by purifying selection. This suggests that these genes have faced strong environmental pressures throughout their evolution. Purifying selection typically results in a decrease in genetic diversity. The estimated duplication time for CHX paralogous gene pairs ranged from approximately 26.965 to 245.413 million years ago (Mya), while the duplication time for SOS paralogous gene pairs ranged from around 116.682 to 275.631 Mya. For RLK paralogous gene pairs, the duplication time varied from approximately 27.689 to 239.376 Mya. Synteny analysis of the CHX , SOS , and RLK genes demonstrated collinear relationships with orthologous genes in Arabidopsis thaliana , but no collinearity orthologous relationships in Oryza sativa (rice). Furthermore, the analysis revealed that there were 6 orthologous SlCHX genes, 2 orthologous SlSOS genes, and 44 orthologous SlRLK genes paired with those in A. thaliana. The results of the present study may help to elucidate the role of the CHX , SOS , and RLK genes in salt stress in S. lycopersicum .

How and why funders support engaged research

Research that better aligns policy, practice, and research communities is gaining momentum around the world. This includes engaged research strategies that bring partners, and their diverse perspectives and kinds of knowledge, together to shape research agendas with on-the-ground-needs and to create dynamic problem-solving processes. These approaches aim to generate more equitable and effective solutions to societal challenges. Although many of these partnered strategies have a longstanding history, entrenched research cultures, practices, and institutional structures stand in the way of scaling them. Given the outsized role funders play in shaping research efforts, funders are a critical lever for change. This perspective describes the efforts of a global collaborative of philanthropic and public funders who are adapting their practices, supporting the development of infrastructure (e.g., capacity-strengthening, facilitation expertise, processes to guide relational work, etc.), and targeting system-level challenges to enable engaged research to maximize its potential. The authors integrate insights from different issue areas, geographies, and funding areas to provide concrete examples of funder activities that support engaged research and to suggest areas for further action. Recommendations include scaling changes in funding practices, deepening understanding of how and when engaged research leads to improved outcomes, and reshaping how success is defined and measured.

Sodium aescinate-induced hepatotoxicity via ATF4/GSH/GPX4 axis-mediated ferroptosis

Evidence for a metal–bosonic insulator–superconductor transition in compressed sulfur

The abrupt drop of resistance to zero at a critical temperature is a key signature of the current paradigm of the metal–superconductor transition. However, the emergence of an intermediate bosonic insulating state characterized by a resistance peak preceding the onset of the superconducting transition has challenged this traditional understanding. Notably, this phenomenon has been predominantly observed in disordered or chemically doped low-dimensional systems, raising intriguing questions about the generality of the effect and its underlying fundamental physics. Here, we present a systematic experimental study of compressed elemental sulfur, an undoped three-dimensional (3D) high-pressure superconductor, with detailed measurements of electrical resistance as a function of temperature, magnetic field, and current. The anomalous resistance peak observed in this 3D system is interpreted based on an empirical model of a metal–bosonic insulator–superconductor transition, potentially driven by vortex dynamics under magnetic field and energy dissipation processes. These findings offer a fresh platform for theoretical analysis of the decades-long enigmatic of the underlying mechanism of this phenomenon.

Optimising detector readout settings for the detection of spatial correlations between SPDC photon-pairs

AbstractSPDC photon-pairs exhibit spatial correlations which can be measured using detector arrays sensitive to single photons. However, these detector arrays have multiple readout modes and in order to optimise detection it is important to select the optimum mode to detect the correlations against a background of optical and electronic noise. These quantum correlations enable applications in imaging, sensing, communication, and optical processing. Here we compare the measurement of spatial correlations for a broad range of readout modes of an EMCCD camera and attempt to characterise the optimal readout mode for our purposes. This assessment is important for the use of detector arrays of different types for use in quantum, low-light, enhanced resolution, imaging systems.

Comparing integrative ventilatory and renal acid–base acclimatization in lowlanders and Tibetan highlanders during ascent to 4,300 m

With over 14 million people living above 3,500 m, the study of acclimatization and adaptation to high altitude in human populations is of increasing importance, where exposure to high altitude (HA) imposes a blood oxygenation and acid–base challenge. A sustained and augmented hypoxic ventilatory response protects oxygenation through ventilatory acclimatization, but elicits hypocapnia and respiratory alkalosis. A subsequent renally mediated compensatory metabolic acidosis corrects pH toward baseline values, with a high degree of interindividual variability. Differential renal compensation between acclimatizing lowlanders (LL) and Tibetan highlanders (TH; Sherpa) with ascent was previously unknown. We assessed ventilatory and renal acclimatization between unacclimatized LL and TH during incremental ascent from 1,400 m to 4,300 m in age- and sex-matched groups of 15-LL (8F) and 14-TH (7F) of confirmed Tibetan ancestry. We compared respiratory and renally mediated blood acid–base acclimatization (PCO 2 , [HCO 3 − ], pH) in both groups before (1,400 m) and following day 8 to 9 of incremental ascent to 4,300 m. We found that following ascent to 4,300 m, LL had significantly lower PCO 2 ( P <0.0001) and [HCO 3 − ] ( P <0.0001), and higher pH ( P = 0.0037) than 1,400 m, suggesting respiratory alkalosis and only partial renal compensation. Conversely, TH had significantly lower PCO 2 ( P < 0.0001) and [HCO 3 − ] ( P < 0.0001), but unchanged pH ( P = 0.1), suggesting full renal compensation, with significantly lower PCO 2 ( P = 0.01), [HCO 3 − ] ( P < 0.0001) and pH ( P = 0.005) than LL at 4,300 m. This demonstration of differential integrative respiratory–renal responses between acclimatizing LL and TH may indicate selective pressure on TH, and highlights the important role of the kidneys in acclimatization.

Structural, magnetic, and optical characteristics of undoped and chromium, iron, cobalt, copper, and zinc doped nickel oxide nanopowders

Integration of basal and apical embryo lineage regulators controls F-actin cable integrity and zygote asymmetry in <i>Arabidopsis</i>

In many plants, the asymmetric division of the zygote sets up the apical–basal body axis. In the cress Arabidopsis , the zygote coexpresses regulators of the apical and basal embryo lineages, the transcription factors WOX2 and WRKY2/WOX8, respectively. WRKY2/WOX8 activity promotes nuclear migration, cellular polarity, and mitotic asymmetry of the zygote, which are hallmarks of axis formation in many plant species. However, the role of WOX2 and how the antagonistic WOX2 and WRKY2/WOX8 functions are integrated in the zygote have remained a long-standing question. Here, we report that WOX2 loss-of-function completely suppresses the reduced zygote asymmetry of wrky2 mutants and that WOX2 overexpression mimics the wrky2 phenotype. At the molecular level, WRKY2 downregulates WOX2 transcription in the zygote and the basal embryo lineage, in addition to promoting WOX8 expression. WOX2 antagonizes WRKY2 function by repressing WOX8 transcription. As a physiological readout, the WRKY2/WOX8-WOX2 balance regulates the integrity of F-actin cables in the zygote, providing a mechanistic framework for the role of WRKY2/WOX8-WOX2-mediated zygote asymmetry.

Creep model of bond-degradation in deep granite based on variable radius particle clump

Liquid-nano-liquid interface–oriented anisotropic encapsulation

Emulsion interface engineering has been widely employed for the synthesis of nanomaterials with various morphologies. However, the instability of the liquid–liquid interface and uncertain interfacial interactions impose significant limitations on controllable fabrications. Here, we developed a liquid-nano-liquid interface–oriented anisotropic encapsulation strategy for fabricating asymmetric nanohybrids. Specifically, functional nanoparticles such as magnetic nanoparticles, lanthanide fluorescent nanoparticles, and Au nanorods were anisotropically encapsulated by mesoporous polydopamine (mPDA). In this emulsion system, the wetting behavior of functional nanoparticles at the water/oil interface could be manipulated by the stabilizer of the emulsion (surfactant), leading to the anisotropic assembly of mPDA shell and resulting in various nanostructures, including core–shell, yolk–shell with small opening, ball-in-bowl, and multipetal structures. Due to their structural asymmetry, inherent magnetic properties, and photothermal properties, the ball-in-bowl structured Fe 3 O 4 @SiO 2 &amp;mPDA nanohybrids, serving as proof of concept for nanomotors, demonstrated effective penetration of bacterial biofilm and promotion of infected wound healing. Overall, our approach offers a different perspective for designing morphologically controllable asymmetric structures based on liquid-nano-liquid interface in microemulsion systems that hold great potential for establishing innovative functional nanomaterials.

Publisher Correction: A novel sustainable biocide against the fruit fly Drosophila suzukii made from orange peels

Energy–poverty–inequality SDGs: A large-scale household analysis and forecasting in China

Affordable and clean energy, eliminating poverty, and reducing inequality are important goals of the United Nations Sustainable Development Goals (SDGs). This paper examines the role of access to clean cooking fuels in promoting income growth and reducing income inequality. Using data from Chinese households, we show that a 10% increase in the adoption of clean cooking fuels would result in an increase in total annual household income of US$37 billion nationwide. Income growth from access to clean cooking fuels is greater for lower-income groups due to a shift to higher household income and reduced downward household income mobility, which contributes to a reduction in income inequality. The effect of access to clean cooking fuels on household income growth is primarily driven by improved health and increased labor supply. The use of clean cooking fuels also saves fuel collection time and cooking time, reducing time spent on household chores by about 0.4 h per day, thereby increasing labor supply in the job market and improving wage income. Improvements in income due to clean cooking fuels are influenced by external conditions, urbanization, education, employment opportunities, and good market conditions. With further promotion of clean cooking fuels, household income and inequality in China are expected to improve further by 2030 and contribute more widely to human well-being and achievement of the SDGs.

Hybrid Prairie Dog and Dwarf Mongoose optimization algorithm-based application placement and resource scheduling technique for fog computing environment

The unequal adoption of ChatGPT exacerbates existing inequalities among workers

We study the adoption of ChatGPT, the icon of Generative AI, using a large-scale survey linked to comprehensive register data in Denmark. Surveying 18,000 workers from 11 exposed occupations, we document that ChatGPT is widespread, especially among younger and less-experienced workers. However, substantial inequalities have emerged. Women are 16 percentage points less likely to have used the tool for work. Furthermore, despite its potential to lift workers with less expertise, users of ChatGPT earned slightly more already before its arrival, even given their lower tenure. Workers see a substantial productivity potential in ChatGPT but are often hindered by employer restrictions and a perceived need for training.

Health risks evaluation of mycotoxins in plant-based supplements marketed in Malaysia

Gonadal sex and temperature independently influence germ cell differentiation and meiotic progression in <i>Trachemys scripta</i>

In species with genetic sex determination (GSD), the sex identity of the soma determines germ cell fate. For example, in mice, XY germ cells that enter an ovary differentiate as oogonia, whereas XX germ cells that enter a testis initiate differentiation as spermatogonia. However, numerous species lack a GSD system and instead display temperature-dependent sex determination (TSD). In the red-eared slider turtle, Trachemys scripta , a TSD model species with a warm female promoting temperature (FPT) and cool male promoting temperature (MPT) system, temperature directly affects germ cell number. In this study, we examined whether temperature directly affects other aspects of germ cell differentiation/sex identity. We uncoupled temperature and the sexual fate of the gonad by incubating eggs at MPT and treating with 17β-estradiol, a scheme that invariably produces ovaries. Through analysis of meiotic spreads, we showed that germ cells in FPT ovaries follow the typical pattern of initiating meiosis and progress through prophase I. However, in E2-induced ovaries that incubated at MPT, germ cells entered prophase I yet fail to exhibit synapsis. These results, combined with our single-cell transcriptome analysis, reveal a direct effect of temperature on germ cell sexual differentiation independent of its effect on the gonadal soma. These results imply that not all events of meiosis are under somatic control, at least not in this TSD species.