Circular at the very beginning: on the initial genomes in the RNA world.

It is likely that an RNA world existed in early life, when RNA played both the roles of the genome and functional molecules, thereby undergoing Darwinian evolution. However, even with only one type of polymer, it seems quite necessary to introduce a labour division concerning these two roles because folding is required for functional molecules (ribozymes) but unfavourable for the genome (as a template in replication). Notably, while ribozymes tend to have adopted a linear form for folding without constraints, a circular form, which might have been topologically hindered in folding, seems more suitable for an RNA template. Another advantage of involving a circular genome could have been to resist RNA's end-degradation. Here, we explore the scenario of a circular RNA genome plus linear ribozyme(s) at the precellular stage of the RNA world through computer modelling. The results suggest that a one-gene scene could have been 'maintained', albeit with rather a low efficiency for the circular genome to produce the ribozyme, which required precise chain-break or chain-synthesis. This strict requirement may have been relieved by introducing a 'noncoding' sequence into the genome, which had the potential to derive a second gene through mutation. A two-gene scene may have 'run well' with the two corresponding ribozymes promoting the replication of the circular genome from different respects. Circular genomes with more genes might have arisen later in RNA-based protocells. Therefore, circular genomes, which are common in the modern living world, may have had their 'root' at the very beginning of life.

Genome-wide identification of Rosa roxburghii CML family genes identifies an RrCML13-RrGGP2 interaction involved in calcium-mediated regulation of ascorbate biosynthesis.

Calmodulin-like proteins (CMLs) are an essential family of calcium sensors involved in multiple Ca2+-mediated cellular processes in plants. Rosa roxburghii Tratt, known for the abundance of L-ascorbic acid (AsA) in its fruits, is widely distributed in calcium-rich soil of the karst region in southwestern China. The aim of this study was to identify key CMLs that respond to exogenous Ca2+ levels and regulate AsA biosynthesis in R. roxburghii. A genome-wide scan revealed the presence of 41 RrCML genes with 1-4 EF-hand motif (s) unevenly distributed across the 7 chromosomes of R. roxburghii. qRT-PCR analysis revealed that RrCML13, RrCML10, and RrCML36 responded significantly to exogenous Ca2+ treatment, and RrCML13 was positively correlated with GDP-L-galactose phosphorylase encoding gene (RrGGP2) expression and AsA content in the developing fruit. Overexpression of RrCML13 in fruits and roots significantly promoted the transcription of RrGGP2 and the accumulation of AsA, while virus-induced silencing of RrCML13 reduced the transcription of RrGGP2 and the content of AsA. Furthermore, Moreover, the yeast two-hybrid and bimolecular fluorescence complementation (BiFC) analysis confirmed the interaction between RrCML13 and RrGGP2 proteins, indicating that RrCML13 plays a regulatory role in calcium-mediated AsA biosynthesis. This study enhances our understanding of R. roxburghii CMLs and sheds light on the calcium-mediated regulation of AsA biosynthesis.

The dual role of FSP1 in programmed cell death: resisting ferroptosis in the cell membrane and promoting necroptosis in the nucleus of THP-1 cells.

BACKGROUND: Acute monocytic leukemia-M5 (AML-M5) remains a challenging disease due to its high morbidity and poor prognosis. In addition to the evidence mentioned earlier, several studies have shown that programmed cell death (PCD) serves a critical function in treatment of AML-M5. However, the role and relationship between ferroptosis and necroptosis in AML-M5 remains unclear. METHODS: THP-1 cells were mainly treated with Erastin and IMP-366. The changes of ferroptosis and necroptosis levels were detected by CCK-8, western blot, quantitative real-time PCR, and electron microscopy. Flow cytometry was applied to detect the ROS and lipid ROS levels. MDA, 4-HNE, GSH and GSSG were assessed by ELISA kits. Intracellular distribution of FSP1 was studied by immunofluorescent staining and western blot. RESULTS: The addition of the myristoylation inhibitor IMP-366 to erastin-treated acute monocytic leukemia cell line THP-1 cell not only resulted in greater susceptibility to ferroptosis characterized by lipid peroxidation, glutathione (GSH) depletion and mitochondrial shrinkage, as the FSP1 position on membrane was inhibited, but also increased p-RIPK1 and p-MLKL protein expression, as well as a decrease in caspase-8 expression, and triggered the characteristic necroptosis phenomena, including cytoplasmic translucency, mitochondrial swelling, membranous fractures by FSP1 migration into the nucleus via binding importin α2. It is interesting to note that ferroptosis inhibitor fer-1 reversed necroptosis. CONCLUSION: We demonstrated that inhibition of myristoylation by IMP-366 is capable of switching ferroptosis and ferroptosis-dependent necroptosis in THP-1 cells. In these findings, FSP1-mediated ferroptosis and necroptosis are described as alternative mechanisms of PCD of THP-1 cells, providing potential therapeutic strategies and targets for AML-M5.

PA-MSHA improves prognosis of patients undergoing radical cystectomy: a retrospective cohort study using inverse probability of treatment weighting.

Objective: To observe the effect of Pseudomonas aeruginosa mannose-sensitive hemagglutinin (PA-MSHA) on the prognosis and the incidence of lymphatic leakage in patients undergoing radical cystectomy (RC). Method: A total of 129 patients who underwent RC in Lanzhou University Second Hospital from 2013 to 2022 were enrolled in this study. They were divided into 43 patients treated with PA-MSHA and 86 patients in the control group. Inverse probability of treatment weighting (IPTW) was applied to reduce potential selection bias. Kaplan-Meier method and Cox regression analysis were used to analyze the effect of PA-MSHA on the survival of patients and the incidence of postoperative lymphatic leakage. Results: The PA-MSHA group exhibited improved overall survival (OS) and cancer-specific survival (CSS) rates compared to the control group. The 3-year and 5-year overall survival (OS) rates for the PA-MSHA group were 69.1% and 53.2%, respectively, compared to 55.6% and 45.3% for the control group (Log-rank=3.218, P=0.072). The 3-year and 5-year cancer-specific survival (CSS) rates for the PA-MSHA group were 73.3% and 56.5%, respectively, compared to 58.0% and 47.3% for the control group (Log-rank=3.218, P=0.072). Additionally, the 3-year and 5-year progression-free survival (PFS) rates for the PA-MSHA group were 74.4% and 56.8%, respectively, compared to 57.1% and 52.2% for the control group (Log-rank=2.016, P=0.156). Multivariate Cox regression analysis indicates that lymph node metastasis and distant metastasis are poor prognostic factors for patients, while the use of PA-MSHA can improve patients' OS (HR: 0.547, 95%CI: 0.304-0.983, P=0.044), PFS (HR: 0.469, 95%CI: 0.229-0.959, P=0.038) and CSS (HR: 0.484, 95%CI: 0.257-0.908, P=0.024). The same trend was observed in the cohort After IPTW adjustment. Although there was no significant difference in the incidence of postoperative lymphatic leakage [18.6% (8/35) vs. 15.1% (84.9%), P=0.613] and pelvic drainage volume [470 (440) ml vs. 462.5 (430) ml, P=0.814] between PA-MSHA group and control group, PA-MSHA could shorten the median retention time of drainage tube (7.0 d vs 9.0 d) (P=0.021). Conclusion: PA-MSHA may improve radical cystectomy in patients with OS, PFS, and CSS, shorten the pelvic drainage tube retention time.

Lactobacillus acidophilus protects against Corynebacterium pseudotuberculosis infection by regulating the autophagy of macrophages and maintaining gut microbiota homeostasis in C57BL/6 mice.

Corynebacterium pseudotuberculosis (C. p), a facultative intracellular bacterium, is an important zoonotic pathogen that causes abscesses and pyogenic granulomas. The relationship between gut microbiota and host health or diseases has received increasing attention. However, the role of gut microbiota in the process of C. p infection is still unclear. In this study, we established a C. p infection model in C57BL/6 mice and examined the impact of preemptive oral administration Lactobacillus acidophilus (L. acidophilus) on infection. Our findings revealed that C. p infection led to pronounced pathological alterations in the liver and kidneys, characterized by abscess formation, intense inflammatory responses, and bacterial overload. Remarkably, these deleterious effects were greatly relieved by oral administration of L. acidophilus before infection with C. p. Additionally, we further found that during C. p infection, peritoneal macrophages (PMs) of mice orally administered with L. acidophilus accumulated more rapidly at sites of infection. Furthermore, our results showed that PMs from mice with oral L. acidophilus administration showed a stronger C. p clearance effect, and this was mediated by high expression of LC3-II protein. Meanwhile, oral administration of L. acidophilus protected the gut microbiota disorder in C57BL/6 mice caused by C. p infection. In summary, our study demonstrates that oral administration of L. acidophilus confers effective protection against C. p infection in C57BL/6 mice by modulating macrophage autophagy, thereby augmenting bacterial clearance and preserving gut microbiota and function stability. These findings position L. acidophilus as a viable probiotic candidate for the clinical prevention of C. p infection. IMPORTANCE: Corynebacterium pseudotuberculosis (C. p) is known to induce a range of chronic diseases in both animals and humans. Currently, clinical treatment for C. p infection mainly relies on antibiotic therapy or surgical intervention. However, excessive use of antibiotics may increase the risk of drug-resistant strains, and the effectiveness of treatment remains unsatisfactory. Furthermore, surgical procedures do not completely eradicate pathogens and can easily cause environmental pollution. Probiotic interventions are receiving increasing attention for improving the body's immune system and maintaining health. In this study, we established a C. p infection model in C57BL/6 mice to explore the impact of Lactobacillus acidophilus during C. p infection. Our results showed that L. acidophilus effectively protected against C. p infection by regulating the autophagy of macrophages and maintaining intestinal microbiota homeostasis. This study may provide a new strategy for the prevention of C. p infection.

Research on the Shale Reservoir Sensitivity by Using the Mineral Analysis Method.

Shale reservoirs have diverse mineral types, and analyzing the sensitivity of the mineral composition to shale pores is of great scientific and engineering significance. In this paper, first, X-ray diffraction (XRD) experiments on shale mineral compositions are carried out, and the characteristics of pore structure changes after shale mineral compositions interacted with external fluids (slick water and backflow fluid) are elucidated. Then, the effects of quartz, kaolinite, and pyrite on the pore structure and permeability of shale on the susceptibility to slick water are studied. The results show that (a) quartz and clay minerals are the dominant constituents of each core, with some cores containing minor amounts of plagioclase feldspar and rhodochrosite. (b) The composition of the shale changed significantly following the action of external fluids. The average quartz content of pure shale decreased from 31.62% to 29.1%. The average content of quartz in siliceous shale decreased from 36.53% to 33.5%. The average content of quartz in carbonaceous shale decreased from 9.15% to 8.05%. (c) Factors affecting the sensitivity of shale pore structure and permeability to slick water are mainly quartz, kaolinite, and pyrite. The contents of quartz, kaolinite, and pyrite decreased by an average of 5.1%, 4.6%, and 0.9%, respectively, after slick water action.

Transcriptome analysis revealed the new mechanism of the intra-myocardial injectable alginate-hydrogel in the treatment of ventricular function degradation.

Background: Myocardial infarction (MI) is one of the most lethal cardiovascular diseases. The loss of cardiomyocytes and the degradation of the extracellular matrix leads to high ventricular wall stress, which further drives the pathological thinning of the ventricular wall during MI. Injecting biomaterials to thicken the infarct ventricular wall provides mechanical support, thereby inhibiting the continued expansion of the heart. As an injectable biomaterial, alginate hydrogel has achieved exciting results in clinical trials, but further research needs to be conducted to determine whether it can improve cardiac function in addition to providing mechanical support. This study sought to explore these mechanisms in an animal model of MI. Methods: A MI model was established in male C57BL/6J mice by ligation of the proximal left anterior descending (LAD) coronary artery. Intramyocardial injections (hydrogel or saline group) were performed in the proximal wall regions bordering the infarct area (with one 20-µL injection). Four weeks after MI, RNA sequencing revealed that 342 messenger RNAs (mRNAs) from the infarcted hearts were differentially expressed between the saline group and hydrogel group. We subsequently conducted a Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis to analyze the RNA sequencing data. In addition, we employed both western blotting and quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) techniques to verify a number of genes that were differentially expressed and could potentially affect cardiac function after MI. Subsequently, we confirmed these findings through in vitro experiments. Results: We found that compared with hydrogel treatment group, 250 mRNAs were upregulated and 92 mRNAs were downregulated in saline group (P<0.05). And by exploring the GO and KEGG signaling pathways as well as the protein-protein interaction (PPI) network, we found that administration of alginate hydrogel modulated cardiomyocyte inflammation-associated proteins as well as chemokine-related proteins during the inflammatory response phase after MI. In addition, our analysis at both the protein and RNA level revealed that B2M was effective in improving cardiac function after MI in the hydrogel treatment group, which was consistent in the myocardium oxygen and glucose deprivation (OGD) injury model. Conclusions: We explored the transcriptome changes of infarcted hearts after alginate-hydrogel injection during the inflammatory response period. Our findings suggest that the injectable hydrogel directly alters the inflammatory response and the chemokine-mediated signaling pathway of cardiomyocytes, ultimately improving cardiac function.

Exosome is a Fancy Mobile Sower of Ferroptosis.

Exosomes, nano-sized small extracellular vesicles, have been shown to serve as mediators between intercellular communications by transferring bioactive molecules, such as non-coding RNA, proteins, and lipids from secretory to recipient cells, modulating a variety of physiological and pathophysiological processes. Recent studies have gradually demonstrated that altered exosome charges may represent a key mechanism driving the pathological process of ferroptosis. This review summarizes the potential mechanisms and signal pathways relevant to ferroptosis and then discusses the roles of exosome in ferroptosis. As well as transporting iron, exosomes may also indirectly convey factors related to ferroptosis. Furthermore, ferroptosis may be transmitted to adjacent cells through exosomes, resulting in cascading effects. It is expected that further research on exosomes will be conducted to explore their potential in ferroptosis and will lead to the creation of new therapeutic avenues for clinical diseases.

Preparation and application of fluorescent monoclonal antibodies recognizing goat CD4+CD25+ regulatory T cells.

Regulatory T cells (Tregs) are a subset of T cells participating in a variety of diseases including mycoplasmal pneumonia, contagious ecthyma, and so on. The role of Tregs in goat contagious ecthyma is not completely understood due to the lack of species-specific antibodies. Here, we developed a combination of CD4 and CD25 fluorescence monoclonal antibodies (mAb) to recognize goat Tregs and assessed its utility in flow cytometry, immunofluorescence staining. Using immunofluorescence staining, we found that the frequency of Treg cells was positively correlated with the viral load during orf virus infection. These antibodies could serve as important tools to monitor Tregs during orf virus infection in goats. KEY POINTS: • A combination of fluorescent mAbs (C11 and D12) was prepared for the detection of goat Tregs. • C11 and D12 are effective in flow cytometry, immunofluorescence staining, and C11 has excellent species specificity. • The frequency of Treg cells was positively correlated with the viral load during orf virus infection.

Colchicine Blocks Abdominal Aortic Aneurysm Development by Maintaining Vascular Smooth Muscle Cell Homeostasis.

Development of non-surgical treatment of human abdominal aortic aneurysm (AAA) has clinical significance. Colchicine emerges as an effective therapeutic regimen in cardiovascular diseases. Yet, whether colchicine slows AAA growth remain controversy. Here, we demonstrated that daily intragastric administration of low-dose colchicine blocked AAA formation, prevented vascular smooth muscle cell (SMC) phenotype switching and apoptosis, and vascular inflammation in both peri-aortic CaPO4 injury and subcutaneous angiotensin-II infusion induced experimental AAA mice models. Mechanistically, colchicine increased global mRNA stability by inhibiting the METTL14/YTHDC1-mediated m6A modification, resulting in increased sclerostin (SOST) expression and consequent inactivation of the WNT/ß-catenin signaling pathway in vascular SMCs from mouse AAA lesions and in cultured human aortic SMCs. Moreover, human and mouse AAA lesions all showed increased m6A methylation, decreased SOST expression, and skewed synthetic SMC de-differentiation phenotype, compared to those without AAA. This study uncovers a novel mechanism of colchicine in slowing AAA development by using the METTL14/SOST/WNT/ß-catenin axis to control vascular SMC homeostasis in mouse aortic vessels and in human aortic SMCs. Therefore, use of colchicine may benefit AAA patients in clinical practice.

Political incentives in market-based environmental regulation: Evidence from China's carbon emissions trading scheme.

This paper used a multi-period DID model with panel data from 283 Chinese cities between 2006 and 2019 to investigate the emission reduction effects and mechanisms of China's carbon trading scheme. The research revealed that China's Carbon Emissions Trading Scheme not only stimulated businesses to reduce emissions as a market-based environmental regulation policy but also influenced local governments' governance objectives. As a result, the Hawthorne effect inevitably manifested during the experimental period of China's Carbon Emissions Trading Scheme. Further analysis indicated that China's CETS encouraged local authorities to take a more proactive stance towards the balance between environmental preservation and economic growth, aiming to achieve a mutually beneficial outcome. Based on the political stance of local governments, they are likely to simultaneously increase their focus on both economic growth and environmental protection. However, when faced with the conflict between economic advancement and environmental safeguarding, pilot regions prioritized ecological conservation in their practical steps, leading to a modest decline in economic growth. In other words, the government's high-profile announcements may not always manifest in actual deeds. In practice, local authorities tend to allocate more administrative resources to areas highly prioritized by the central government. Furthermore, the extended analysis reveals that China's CETS has resulted in a reduction in social welfare due to a shift in governance priorities influenced by political incentives. Therefore, fine-tuning the performance evaluation mechanism, preventing any bias towards the target preferences of local authorities, and guaranteeing the successful operation of the market mechanism are imperative to achieve truly low-cost and sustainable emissions reductions objectives for CETS.

Data of compressible multi-material flow simulations utilizing an efficient bimaterial Riemann problem solver.

This paper presents fluid dynamics simulation data associated with two test cases in the related research article [1]. In this article, an efficient bimaterial Riemann problem solver is proposed to accelerate multi-material flow simulations that involve complex thermodynamic equations of state and strong discontinuities across material interfaces. The first test case is a one-dimensional benchmark problem, featuring large density jump (4 orders of magnitude) and drastically different thermodynamics relations across a material interface. The second test case simulates the nucleation of a pear-shaped vapor bubble induced by long-pulsed laser in water. This multiphysics simulation combines laser radiation, phase transition (vaporization), non-spherical bubble expansion, and the emission of acoustic and shock waves. Both test cases are performed using the M2C solver, which solves the three-dimensional Eulerian Navier-Stokes equations, utilizing the accelerated bimaterial Riemann solver. Source codes provided in this paper include the M2C solver and a standalone version of the accelerated Riemann problem solver. These source codes serve as references for researchers seeking to implement the acceleration algorithms introduced in the related research article. Simulation data provided include fluid pressure, velocity, density, laser radiance and bubble dynamics. The input files and the workflow to perform the simulations are also provided. These files, together with the source codes, allow researchers to replicate the simulation results presented in the research article, which can be a starting point for new research in laser-induced cavitation, bubble dynamics, and multiphase flow in general.

Accelerated marine carbon cycling forced by tectonic degassing over the Miocene Climate Optimum.

Global warming during the Miocene Climate Optimum (MCO, ∼17-14 million years ago) is associated with massive carbon emissions sourced from the flood basalt volcanism and ocean crustal production. However, the perturbation of tectonic carbon degassing on the interaction between climate change and carbon cycle remains unclear. Here, through time-evolutive phase analysis of new and published high-resolution benthic foraminiferal oxygen (δ18O) and carbon (δ13C) isotope records from the global ocean, we find that variations in the marine carbon cycle lead the climate-cryosphere system (δ13C-lead-δ18O) on 405,000-year eccentricity timescales during the MCO. This is in contrast to the previously reported climate-lead-carbon (δ18O-lead-δ13C) scenario during most of the Oligo-Miocene (∼34-6 million years ago). Further sensitivity analysis and model simulations suggest that the elevated atmospheric CO2 concentrations and the resulting greenhouse effect strengthened the low-latitude hydrological cycle during the MCO, accelerating the response of marine carbon cycle to eccentricity forcing. Tropical climate processes played a more important role in regulating carbon-cycle variations when Earth's climate was in a warm regime, as opposed to the dominant influence of polar ice-sheet dynamics during the Plio-Pleistocene (after ∼6 million years ago).

P53: A Key Target in the Development of Osteoarthritis.

Osteoarthritis (OA), a chronic degenerative disease characterized mainly by damage to the articular cartilage, is increasingly relevant to the pathological processes of senescence, apoptosis, autophagy, proliferation, and differentiation of chondrocytes. Clinical strategies for osteoarthritis can only improve symptoms and even along with side effects due to age, sex, disease, and other factors. Therefore, there is an urgent need to identify new ideas and targets for current clinical treatment. The tumor suppressor gene p53, which has been identified as a potential target for tumor therapeutic intervention, is responsible for the direct induction of the pathological processes involved in OA modulation. Consequently, deciphering the characteristics of p53 in chondrocytes is essential for investigating OA pathogenesis due to p53 regulation in an array of signaling pathways. This review highlights the effects of p53 on senescence, apoptosis, and autophagy of chondrocytes and its role in the development of OA. It also elucidates the underlying mechanism of p53 regulation in OA, which may help provide a novel strategies for the clinical treatment of OA.

In vitro antioxidant activity of the polysaccharide from Auricularia auricula and its structural characterisation.

A new polysaccharide (AAP) was extracted from Auricularia auricula by water extraction and alcohol precipitation. The antioxidant activity in vitro showed that AAP had a good scavenging effect on ABTS free radicals. Then AAP was purified by DEAE-52 ion exchange chromatography to obtain the purified component pAAP. The structure analysis showed that the molecular weight (Mw) of pAAP was 96.768 kDa, which was composed of rhamnose (Rha), arabinose (Ara), fucose (Fuc), xylose (Xyl), mannose (Man), glucose (Glu) and galactose (Gal), with the ratio of 0.1:0.157:0.33:2.797:2.881:2.988:0.587, and contained α-pyranose configuration and ß-pyranose configuration. Field emission scanning electron microscopy and atomic force microscopy revealed the special conformation of pAAP in the ring and chain shape.

Time-resolved fluorescence microspheres-antibody-penicillin-binding protein assisted construction of immunochromatographic assay for sensitive detection of 22 ß-lactams in milk.

A sensitive immunochromatographic assay (ICA) using time-resolved fluorescence microspheres (TRFMs) coupled with an indirect-labeling mode was developed for simultaneously determining 22 kinds of ß-lactams in milk samples. The TRFMs labeled anti-receptor monoclonal antibodies (mAbs) conjugated to penicillin-binding proteins (PBPs) as ternary TRFMs-mAb-PBPs (TMP) nanoscaffolds provide excellent solubility, brightness, and stability. Thanks to the fact that they not only fully expose the binding sites of PBPs, thereby enhancing the biological affinity of PBPs towards the target, but also generated superb fluorescence signals, the versatile TMP manifested unique possibilities as efficient probes for ICA with remarkable enhancement in sensitivity in ß-lactams screening. The results showed that the standard curves of the 22 varying ß-lactams displayed linearity in their respective concentration ranges (R2 > 0.98), with the cutoff values of 1-100 ng/mL. The constructed TMP-ICA was successfully applied to the analysis of real milk, with consistent results compared with liquid chromatography-tandem mass spectrometry (LC-MS), providing an effective method for sensing ß-lactams in food matrices.

Dual analysis of wild-type and attenuated Orf virus and host cell transcriptomes revealed novel virus-host cell interactions.

IMPORTANCE: Currently, the only available commercial vaccines for Orf virus (ORFV) are live attenuated vaccines, which present a potential risk of reversion to virulence. Therefore, understanding the pathogenic mechanisms of different virulent strains of ORFV and host immune responses triggered by these viruses is crucial for developing new vaccines and interventions. In this study, we found that the attenuated strain downregulates the host innate immune response and antiviral activity. In addition, we noted that the wild-type strain can induce the immune response pattern centered on interferon-stimulated genes and interferon regulatory factor gene family. We predicted that STAT1 and STAT2 are the main transcription factors upstream of target gene promoters through gene regulatory networks and exert significant regulatory effects on co-expressed genes. Our study elucidated the complex interaction between ORFV strains and host cell immune responses, providing new insights into vaccine research for ORFV.

Effect of nano-calcium on carotenoid and anthocyanin contents of nectarine fruit.

Increasing the carotenoid content of nectarine (Prunus persica var. nucipersica) is of great significance for improving its quality and economic value. A two years study was carried out on 'Shuguang' nectarine to evaluate the effect of calcium chloride (Cl-Ca) and L-aspartic acid nano calcium [Ca (L-asp) - NPs] (nano-Ca) on carotenoid accumulation. The results show that both Cl-Ca and nano-Ca could increase the carotenoid content of nectarine fruit flesh, but the effect of nano-Ca was more significant. Nano-Ca is more easily absorbed by nectarine leaves and fruits, which improves the calmodulin activity of leaves, peel and flesh, and up-regulates the expression of carotenoid synthesis-related genes PpPSY, PpPDS, PpZDS, PpLCY-B, PpCHY-B and PpZEP. Nano-Ca also significantly up-regulated the expression of sucrose synthesis related genes PpSUS1 and PpSUS3 in leaves and sucrose transport related genes PpSUT2 and PpSUT4 in stem phloem, promoting the transport of more photosynthetic products to fruits, providing raw materials for carotenoid synthesis, and increasing the content of total sugars and ascorbic acid (Vc). In addition, nano-Ca can also up-regulate the expression levels of PpMYB10.1 and PpUFGT and promote total anthocyanins accumulation in peel. The results of our study will be useful for clarifying how nano-fertilizer improve the fruit quality of nectarine.

Natural ocean iron fertilization and climate variability over geological periods.

Marine primary producers are largely dependent on and shape the Earth's climate, although their relationship with climate varies over space and time. The growth of phytoplankton and associated marine primary productivity in most of the modern global ocean is limited by the supply of nutrients, including the micronutrient iron. The addition of iron via episodic and frequent events drives the biological carbon pump and promotes the sequestration of atmospheric carbon dioxide (CO2 ) into the ocean. However, the dependence between iron and marine primary producers adaptively changes over different geological periods due to the variation in global climate and environment. In this review, we examined the role and importance of iron in modulating marine primary production during some specific geological periods, that is, the Great Oxidation Event (GOE) during the Huronian glaciation, the Snowball Earth Event during the Cryogenian, the glacial-interglacial cycles during the Pleistocene, and the period from the last glacial maximum to the late Holocene. Only the change trend of iron bioavailability and climate in the glacial-interglacial cycles is consistent with the Iron Hypothesis. During the GOE and the Snowball Earth periods, although the bioavailability of iron in the ocean and the climate changed dramatically, the changing trend of many factors contradicted the Iron Hypothesis. By detangling the relationship among marine primary productivity, iron availability and oceanic environments in different geological periods, this review can offer some new insights for evaluating the impact of ocean iron fertilization on removing CO2 from the atmosphere and regulating the climate.

A New Efficient Multi-Object Detection and Size Calculation for Blended Tobacco Shreds Using an Improved YOLOv7 Network and LWC Algorithm.

Detection of the four tobacco shred varieties and the subsequent unbroken tobacco shred rate are the primary tasks in cigarette inspection lines. It is especially critical to identify both single and overlapped tobacco shreds at one time, that is, fast blended tobacco shred detection based on multiple targets. However, it is difficult to classify tiny single tobacco shreds with complex morphological characteristics, not to mention classifying tobacco shreds with 24 types of overlap, posing significant difficulties for machine vision-based blended tobacco shred multi-object detection and unbroken tobacco shred rate calculation tasks. This study focuses on the two challenges of identifying blended tobacco shreds and calculating the unbroken tobacco shred rate. In this paper, a new multi-object detection model is developed for blended tobacco shred images based on an improved YOLOv7-tiny model. YOLOv7-tiny is used as the multi-object detection network's mainframe. A lightweight Resnet19 is used as the model backbone. The original SPPCSPC and coupled detection head are replaced with a new spatial pyramid SPPFCSPC and a decoupled joint detection head, respectively. An algorithm for two-dimensional size calculation of blended tobacco shreds (LWC) is also proposed, which is applied to blended tobacco shred object detection images to obtain independent tobacco shred objects and calculate the unbroken tobacco shred rate. The experimental results showed that the final detection precision, mAP@.5, mAP@.5:.95, and testing time were 0.883, 0.932, 0.795, and 4.12 ms, respectively. The average length and width detection accuracy of the blended tobacco shred samples were -1.7% and 13.2%, respectively. The model achieved high multi-object detection accuracy and 2D size calculation accuracy, which also conformed to the manual inspection process in the field. This study provides a new efficient implementation method for multi-object detection and size calculation of blended tobacco shreds in cigarette quality inspection lines and a new approach for other similar blended image multi-object detection tasks.