95 research outputs found

    Characterization of auxin-ethylene interactions during the tomato fruit development: role of Sl-IAA17 gene

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    Les interactions entre l’auxine et l’éthylène sont complexes et contrôlent divers processus de développement des plantes tels que l’élongation racinaire ou la différentiation des racines secondaires. Mais, il existe peu d’études montrant le rôle des interactions entre ces deux hormones au cours du développement et de la maturation des fruits. Le changement de couleur des fruits chez la tomate est une caractéristique de la maturation qui est associée à la fois à la dégradation des chlorophylles et à l’accumulation des caroténoïdes. Dans ce travail, l’application exogène d’auxine et d’éthylène a montré l’impact de ces deux hormones sur la maturation de la tomate et en particulier sur le changement de couleur des fruits. Nous avons montré que l’acide indol-acétique (IAA) retarde la transition du vert à l’orange/rouge, alors que l’éthylène, apporté sous la forme d’acide 1-aminocyclopropane-1-carboxylique (ACC), son précurseur, accélère la coloration des fruits. Par contre, l’inhibition de l’auxine par le PCIB, un antagoniste de l’auxine, provoque les mêmes effets que l’éthylène. L’analyse des caroténoïdes montre que l’ACC comme le PCIB augmente la teneur en lycopène et diminue la teneur en carotène alors que l’IAA provoque l’effet inverse. L’étude de l’accumulation des ARNs messagers de plusieurs gènes clés de la voie de biosynthèse des caroténoïdes a montré que le gène β-lcy codant pour la lycopène cyclase joue un rôle clé dans le contrôle de la biosynthèse et de l’accumulation des pigments et que son expression est fortement dépendante de l’équilibre auxine-éthylène. D’autre part, nos résultats ont montré que le gène rin joue un rôle important dans le contrôle de l’expression des gènes clés de la voie de biosynthèse des caroténoïdes. Pour avoir une meilleure vision des gènes différentiellement exprimés par l’auxine et l’éthylène au cours de la maturation, l’analyse du transcriptome des fruits traités par de l’ACC et de l’IAA a été réalisée par RNA-Seq au laboratoire. Parmi les facteurs de transcriptions étudiés, le gène Sl-IAA17, un membre de la famille des AUX/IAA, est fortement affecté par l’auxine et l’éthylène. La caractérisation fonctionnelle du gène Sl-IAA17 pendant le développement du fruit a été réalisée en créant des lignées transgéniques sous exprimant ce gène en mettant en œuvre la stratégie des ARNs interférents. Ces lignées présentent un phénotype caractéristique produisant des fruits de plus gros calibre que celui des fruits sauvages. Les analyses histologiques des tissus des fruits ont montré que ce phénotype est associé à un péricarpe plus épais. En microscopie, nous avons constaté que l’augmentation de l’épaisseur du péricarpe dans les lignées transgéniques n’était pas due à un plus grand nombre de cellules mais à l’augmentation de la taille des cellules. Enfin, nous avons observé que l’expansion des cellules dans les fruits transgéniques est étroitement couplée avec des niveaux de ploïdie plus élevés que dans les fruits sauvages, ce qui suggère une stimulation du processus endoréduplication. Ces résultats démontrent très clairement l’existence d’une étroite relation entre la signalisation de l’auxine, le contrôle de la taille du volume cellulaire et le processus d’endoréduplication. En conclusion, les résultats présentés fournissent des connaissances nouvelles sur les interactions entre l’auxine et l’éthylène au cours du développement du fruit et en particulier au cours de la transition fruit immature - fruit mature. De plus, ils apportent des éléments nouveaux sur la connaissance du rôle de la voie de signalisation de l’auxine dans le contrôle du développement des fruits charnus et en particulier sur la fonction de certains membres des AUX/IAA sur la détermination du volume et du poids des fruits. ABSTRACT : The interaction between auxin and ethylene are complex and control various processes of plant development, such as root elongation or differentiation of secondary roots. But there are few studies showing the role of interactions between these two hormones during development and maturation of the fruit. The color change in the tomato fruit is a feature of the maturation that is associated with the degradation of the chlorophyll and carotenoid accumulation. In this work, the application of exogenous auxin and ethylene showed the impact of these two hormones in the tomato ripening and in particular the change of fruit color. We have shown that indole-acetic acid (IAA) delays the transition from green to orange / red, while ethylene, supplied as 1-aminocyclopropane-1-carboxylic acid form (ACC), its precursor, accelerated this transition. However the auxin inhibition by p-chlorophenoxy isobutyic acid (PCIB), an auxin antagonist, caused the same effects similar to ethylene. The carotenoid analysis showed that the ACC and PCIB increase the lycopene content and reduced the carotene content while IAA causes the opposite effect. The study of the accumulation of mRNAs for several key genes of the carotenoid biosynthetic pathway has shown that the gene β-lcy encoding lycopene cyclase plays a key role in the control of biosynthesis and accumulation of pigments and that its expression is highly dependent on the auxin-ethylene balance. In addition, our results showed that the rin gene plays an important role in controlling the expression of the key carotenoid biosynthetic pathway genes. To get a better view of differentially expressed genes by auxin and ethylene during ripening, transcriptome analysis of fruits treated with ACC and IAA was performed by a preliminary RNA-Seq approach. Among the transcription factors studied in the laboratory, the gene Sl-IAA17, a member of the family of Aux/IAA was affected by auxin and ethylene. Functional characterization of Sl-IAA17 gene during fruit development was performed by creating transgenic lines under-expressing this gene by RNAi. These lines display a phenotype producing bigger fruit than wild type. Histological analysis of the tissues showed that fruit phenotype is associated with a thicker pericarp. By microscopy, we observed that increasing the thickness of the pericarp in the transgenic lines was not due to a greater number of cells but to the increase in cell size. Finally, we observed that cell expansion in transgenic fruit is tightly coupled with higher ploidy levels than wild fruits, suggesting a stimulation of the endoreduplication process. These results clearly demonstrate the existence of a close relationship between the auxin signal, the control cell size, fruit volume and the endoreduplication process. In conclusion, the results provide new insights into the interactions between auxin and ethylene during fruit development and in particular during the transition immature fruit, mature fruit. In addition, they provide new information on the understanding of the role of the signaling pathway of auxin in controlling the development of fleshy fruits and in particular on the basis of certain members of the AUX/IAA on regulating volume and fruit weight

    Coherent Compensation based ISAC Signal Processing for Long-range Sensing

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    Integrated sensing and communication (ISAC) will greatly enhance the efficiency of physical resource utilization. The design of ISAC signal based on the orthogonal frequency division multiplex (OFDM) signal is the mainstream. However, when detecting the long-range target, the delay of echo signal exceeds CP duration, which will result in inter-symbol interference (ISI) and inter-carrier interference (ICI), limiting the sensing range. Facing the above problem, we propose to increase useful signal power through coherent compensation and improve the signal to interference plus noise power ratio (SINR) of each OFDM block. Compared with the traditional 2D-FFT algorithm, the improvement of SINR of range-doppler map (RDM) is verified by simulation, which will expand the sensing range

    Learning A Coarse-to-Fine Diffusion Transformer for Image Restoration

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    Recent years have witnessed the remarkable performance of diffusion models in various vision tasks. However, for image restoration that aims to recover clear images with sharper details from given degraded observations, diffusion-based methods may fail to recover promising results due to inaccurate noise estimation. Moreover, simple constraining noises cannot effectively learn complex degradation information, which subsequently hinders the model capacity. To solve the above problems, we propose a coarse-to-fine diffusion Transformer (C2F-DFT) for image restoration. Specifically, our C2F-DFT contains diffusion self-attention (DFSA) and diffusion feed-forward network (DFN) within a new coarse-to-fine training scheme. The DFSA and DFN respectively capture the long-range diffusion dependencies and learn hierarchy diffusion representation to facilitate better restoration. In the coarse training stage, our C2F-DFT estimates noises and then generates the final clean image by a sampling algorithm. To further improve the restoration quality, we propose a simple yet effective fine training scheme. It first exploits the coarse-trained diffusion model with fixed steps to generate restoration results, which then would be constrained with corresponding ground-truth ones to optimize the models to remedy the unsatisfactory results affected by inaccurate noise estimation. Extensive experiments show that C2F-DFT significantly outperforms diffusion-based restoration method IR-SDE and achieves competitive performance compared with Transformer-based state-of-the-art methods on 33 tasks, including deraining, deblurring, and real denoising.Comment: 9 pages, 8 figure

    Joint Influence of Individual Choices, Parenting Practices, and Physician Advice on Adolescent Obesity, Nebraska, 2008

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    Introduction Reducing childhood obesity remains a public health priority given its high prevalence and its association with increased risk of adult obesity and chronic diseases. The objective of this study was to examine the joint influence of multiple risk factors on adolescent overweight status. Methods We conducted a random-digit-dialed telephone survey of adolescents aged 12 to 19 years in fall 2008 in a Midwestern city in Nebraska. On the basis of survey data for 791 youths aged 12 to 18 years, we conducted latent class analysis to group youths by the joint occurrence of dietary behavior, physical activity, parenting practices, and physician advice. We then examined the association between the groups and overweight status by using logistic regression, controlling for age, sex, race/ethnicity, and parent and family information. Results Youths were clustered into 3 groups. Group I (52%) were youths with healthy dietary behavior and physical activity, less permissive parenting practices, and physician advice; Group II (30%) were youths with moderately healthy dietary behavior and physical activity, less permissive parenting practices, and no physician advice; and Group III (18%) were youths with unhealthy dietary behavior and physical activity, permissive parenting practices, and physician advice. Youths in Groups I and II were less likely to be overweight than youths in Group III. Conclusions Youths with healthier behavior and less permissive parenting practices were less likely to be overweight. Study findings highlight the need to address obesity risk factors among youths with unhealthy dietary behavior, inadequate exercise, permissive parenting practices, and some physician advice. Tailored interventions should be used to target youths with different obesity risk factors

    Aflatoxin B1-DNA adducts modify the effects of post-operative adjuvant transarterial chemoembolization improving hepatocellular carcinoma prognosis

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    Aim: DNA damage involves in the carcinogenesis of some cancer and may act as a target for therapeutic intervention of cancers. However, it is unclear whether aflatoxin B1 (AFB1)-DNA adducts (ADAs), an important kind of DNA damage caused by AFB1, affect the efficiency of post-operative adjuvant transarterial chemoembolization (po-TACE) treatment improving hepatocellular carcinoma (HCC) survival. Methods: A hospital-based retrospective study, including 318 patients with Barcelona Clinic Liver Cancer (BCLC)-C stage HCC from high AFB1 exposure areas, to investigate the potential effects of ADAs in the tissues with HCC on po-TACE treatment. The amount of ADAs in the cancerous tissues was tested by competitive enzyme-linked immunosorbent assay (c-ELISA). Results: Among these patients with HCC, the average amount of ADAs was 3.00 µmol/mol ± 1.51 µmol/mol DNA in their tissues with cancer. For these patients, increasing amount of ADAs was significantly associated with poorer overall survival (OS) and tumor reoccurrence-free survival (RFS), with corresponding death risk (DR) of 3.69 (2.78–4.91) and tumor recurrence risk (TRR) of 2.95 (2.24–3.88). The po-TACE therapy can efficiently improve their prognosis [DR = 0.59 (0.46–0.76), TRR = 0.63 (0.49–0.82)]. Interestingly, this improving role was more noticeable among these patients with high ADAs [DR = 0.36 (0.24–0.53), TRR = 0.40 (0.28–0.59)], but not among those with low ADAs (P > 0.05). Conclusions: These results suggest that increasing ADAs in the cancerous tissues may be beneficial for po-TACE in ameliorating the survival of patients with HCC

    Improving winter wheat yield estimation by assimilation of the leaf area index from Landsat TM and MODIS data into the WOFOST model

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    To predict regional-scale winter wheat yield, we developed a crop model and data assimilation framework that assimilated leaf area index (LAI) derived from Landsat TM and MODIS data into the WOFOST crop growth model. We measured LAI during seven phenological phases in two agricultural cities in China’s Hebei Province. To reduce cloud contamination, we applied Savitzky–Golay (S–G) filtering to the MODIS LAI products to obtain a filtered LAI. We then regressed field-measured LAI on Landsat TM vegetation indices to derive multi-temporal TM LAIs. We developed a nonlinear method to adjust LAI by accounting for the scale mismatch between the remotely sensed data and the model’s state variables. The TM LAI and scale-adjusted LAI datasets were assimilated into the WOFOST model to allow evaluation of the yield estimation accuracy. We constructed a four-dimensional variational data assimilation (4DVar) cost function to account for the observations and model errors during key phenological stages. We used the shuffled complex evolution–University of Arizona algorithm to minimize the 4DVar cost function between the remotely sensed and modeled LAI and to optimize two important WOFOST parameters. Finally, we simulated winter wheat yield in a 1-km grid for cells with at least 50% of their area occupied by winter wheat using the optimized WOFOST, and aggregated the results at a regional scale. The scale adjustment substantially improved the accuracy of regional wheat yield predictions (R2 = 0.48; RMSE= 151.92 kg ha−1) compared with the unassimilated results (R2 = 0.23;RMSE= 373.6 kg ha−1) and the TM LAI results (R2 = 0.27; RMSE= 191.6 kg ha−1). Thus, the assimilation performance depends strongly on the LAI retrieval accuracy and the scaling correction. Our research provides a scheme to employ remotely sensed data, ground-measured data, and a crop growth model to improve regional crop yield estimates

    The accuracy of soluble urokinase-type plasminogen activator receptor for the diagnosis of neonatal sepsis: a meta-analysis

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    BackgroundNeonatal sepsis is one of the major causes of morbidity and mortality in newborns. However, atypical clinical manifestations and symptoms make the early diagnosis of neonatal sepsis a challenge. Relatively high-serum soluble urokinase-type plasminogen activator receptor (suPAR) has been implicated as a diagnostic biomarker for adult sepsis. Therefore, the meta-analysis is intended to explore the diagnostic value of suPAR for neonatal sepsis.MethodsThe PubMed, Cochrane Library, Embase, Web of Science, China National Knowledge Infrastructure, China Biological Medicine Disk, and Wanfang databases were retrieved from inception to 31 December 2022 to collect diagnostic accuracy studies about suPAR for neonatal sepsis. Two reviewers independently screened the literature, extracted data, and assessed the risk of bias in the included studies using the quality assessment of diagnostic accuracy studies-2 (QUADAS-2) tool. Then, a meta-analysis was performed using Stata 15.0 software.ResultsA total of six articles involving eight studies were included. The results of the meta-analysis showed that the pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were 0.89 [95%CI (0.83–0.93)], 0.94 [95%CI (0.77–0.98)], 14 [95%CI (3.5–55.2)], 0.12 [95%CI (0.08–0.18)], and 117 [95%CI (24–567)], respectively. The area under the curve (AUC) of summary receiver operator characteristic (SROC) curves was 0.92 [95%CI (0.90–0.94)]. Sensitivity analysis confirmed the stability of the results, and publication bias was not observed. Fagan’s nomogram results demonstrated the clinical availability of the findings.ConclusionCurrent evidence suggests that suPAR has potential diagnostic value for neonatal sepsis. Owing to the limited quality of the included studies, more high-quality studies are needed to verify the above conclusion

    The antioxidant activity of polysaccharides from Armillaria gallica

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    The purpose of this study was to investigate the antioxidant activity of Armillaria gallica polysaccharides. It explored whether Armillaria gallica polysaccharides (AgP) could prevent HepG2 cells from H2O2-induced oxidative damage. The results demonstrated that HepG2 cells were significantly protected by AgP, and efficiently suppressed the production of reactive oxygen species (ROS) in HepG2 cells. Additionally, AgP significantly decreased the abnormal leakage of alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) caused by H2O2, protecting cell membrane integrity. It was discovered that AgP was also found to regulate the activities of antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-PX), while reducing malondialdehyde (MDA), thus protecting cells from oxidative damage. According to the flow cytometry analysis and measurement of caspase-3, caspase-8, and caspase-9 activities, AgP could modulate apoptosis-related proteins and attenuate ROS-mediated cell apoptosis
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