Comparison between empirical or functional sinks of organs - Application on Tomato plant

International audienceBiomass partitioning among organs depends on their sink strengths, i.e. their capacity to attract assimilates. Using a descriptive approach, where plant development is driven by thermal time, and empirical laws fitted from experimental data, it is possible to trace back by inverse method the dynamics of biomass partitioning among organs. However, the descriptive sink function suffers from the drawbacks that organ development and biomass accumulation are not interactively related. Moreover, many parameters are required and are difficult to be measured accurately. In this paper an alternative organ sink strength definition is proposed, in which the organ sink size is related to the maximum organ biomass, which in turn depends on its primordium size. The sink strength increases proportionally to its size at the early growth stage and decreases by dampening when its mass approaches the final mass. Comparisons to the standard empirical sink function used in the GreenLab model were conducted on tomato plants. The new functional sinks are more biologically relevant and simulated rather adequately the organ biomass evolution. Further improvement is ongoing to increase simulation accuracy

Decreased expression of long non-coding RNA WT1-AS promotes cell proliferation and invasion in gastric cancer

AbstractTumor recurrence and metastasis remain the major obstacles for the successful treatment of patients diagnosed with gastric cancer. In recent years, long non-coding RNAs (lncRNAs) have been considered as key regulators of tumor behavior. In this study, we investigated the expression and biological role of a newly-identified cancer-related lncRNA, WT1-AS. We found that WT1-AS expression was significantly down-regulated in tumor tissues compared to matched adjacent non-tumor tissues. The WT1-AS expression level was also associated with tumor size and the clinicopathological stage. Cell proliferation, migration, and invasion were inhibited, and the proportion of G0/G1 cells increased when WT1-AS was ectopically-expressed in gastric cancer cells. Furthermore, ectopic expression of WT1-AS was demonstrated to inhibit tumor growth and metastasis in vivo. Finally, we found that WT1-AS overexpression could decrease ERK protein phosphorylation. Our study indicates that WT1-AS is significantly down-regulated in gastric cancers and may be correlated with tumor progression

Oscillations in Functional Structural Plant Growth Models

International audienceThe dynamic model of plant growth GreenLab describes plant architecture and functional growth at the level of individual organs. Structural development is controlled by formal grammars and empirical equations compute the amount of biomass produced by the plant, and its partitioning among the growing organs, such as leaves, stems and fruits. The number of organs initiated at each time step depends on the trophic state of the plant, which is evaluated by the ratio of biomass available in plant to the demand of all the organs. The control of the plant organogenesis by this variable induces oscillations in the simulated plant behaviour. The mathematical framework of the GreenLab model allows to compute the conditions for the generation of oscillations and the value of the period according to the set of parameters. Two case-studies are presented, corresponding to emergence of oscillations associated to fructification and branching. Similar alternating patterns are commonly reported by botanists. In this article, two examples were selected: alternate patterns of fruits in cucumber plants and alternate appearances of branches in Cecropia trees. The model was calibrated from experimental data collected on these plants. It shows that a simple feedback hypothesis of trophic control on plant structure allows the emergence of cyclic patterns corresponding to the observed ones

Synthesis of Carbon Onion and Its Application as a Porous Carrier for Amorphous Drug Delivery

Given the great potential of porous carrier-based drug delivery for stabilising the amorphous form of drugs and enhancing dissolution profiles, this work is focussed on the synthesis and application of carbon onion or onion-like carbon (OLC) as a porous carrier for oral amorphous drug delivery, using paracetamol (PA) and ibuprofen (IBU) as model drugs. Annealing of nanodiamonds at 1100 °C produced OLC with a diamond core that exhibited low cytotoxicity on Caco-2 cells. Solution adsorption followed by centrifugation was used for drug loading and results indicated that the initial concentration of drug in the loading solution needs to be kept below 11.5% PA and 20.7% IBU to achieve complete amorphous loading. Also, no chemical interactions between the drug and OLC could be detected, indicating the safety of loading into OLC without changing the chemical nature of the drug. Drug release was complete in the presence of sodium dodecyl sulphate (SDS) and was faster compared to the pure crystalline drug, indicating the potential of OLC as an amorphous drug carrier

Ecological risk of microplastic toxicity to earthworms in soil: A bibliometric analysis

Accumulation of microplastics (MPs) in soil is a serious environmental concern. Addition of exogenous MPs can alter structure and physicochemical properties of and material transport in soil. MPs are particularly toxic to earthworms, which are soil ecosystem engineers, and exacerbate ecological risks; however, there is a lack of comprehensive and in-depth analyses of how MPs exhibit toxicity to/towards earthworms. In this study, we report a bibliometric analysis of 77 peer-reviewed papers published before December 2021 to systematically analyze how the addition of exogenous MPs contributes to earthworm toxicity and clarify the historical development and research hotspots in this field. We found that first, polyethylene and polystyrene are the most common materials used to study the toxic effects of MPs on earthworms. Second, the toxic mechanisms of MPs on earthworms mainly involve histopathological damage and oxidative stress, as well as serving as carriers of complex pollutants (e.g., heavy metals and organic pollutants) through combined adsorption–desorption. Third, oxidative stress is the typical reaction process of MPs toxicity in earthworms. When the content of MPs in soil exceeds 0.1%, earthworm growth is affected, and oxidative stress is induced, resulting in neural and DNA damage. Based on published studies, the prospects for future research on the ecological risks posed by MPs to earthworms have also been discussed. Overall, our findings help clarify the ecological risk of soil MPs toxicity to earthworms, reveal the mechanism of their toxic effects, and provide a theoretical basis for future studies focusing on establishing a healthy and ecologically sustainable soil environment

A consensus protocol for functional connectivity analysis in the rat brain

Task-free functional connectivity in animal models provides an experimental framework to examine connectivity phenomena under controlled conditions and allows for comparisons with data modalities collected under invasive or terminal procedures. Currently, animal acquisitions are performed with varying protocols and analyses that hamper result comparison and integration. Here we introduce StandardRat, a consensus rat functional magnetic resonance imaging acquisition protocol tested across 20 centers. To develop this protocol with optimized acquisition and processing parameters, we initially aggregated 65 functional imaging datasets acquired from rats across 46 centers. We developed a reproducible pipeline for analyzing rat data acquired with diverse protocols and determined experimental and processing parameters associated with the robust detection of functional connectivity across centers. We show that the standardized protocol enhances biologically plausible functional connectivity patterns relative to previous acquisitions. The protocol and processing pipeline described here is openly shared with the neuroimaging community to promote interoperability and cooperation toward tackling the most important challenges in neuroscience

Pricing decision of a dual-channel supply chain with different payment, corporate social responsibility and service level

Strategies such as price, CSR, and service have an important impact on enterprises and supply chains. This paper proposes a two-echelon dual-channel supply chain composed of a manufacturer and a retailer. Considering the product pricing, CSR level, and service level in the supply chain, this paper employs the Stackelberg game to depict supply chain participants’ optimal decisions and analyze the influence of explanatory variables on the optimal decision with retailer’s payment methods. The results state that market share, service level, CSR, and financing interest rate significantly impact the pricing decision of all participants in the supply chain. In addition, strategies of CSR level and service level are also affected by the discount rate of advance payment, financing interest rate, return on investment, and opportunity cost rate. This paper incorporates CSR and service level into the objective function, considers a variety of retailers’ payment methods, enriches the supply chain’s pricing model, and is of great value to scientific decision-making of enterprises and sustainable development of supply chains

Monitoring the Land Cover Change of China with the Combination of the Topex/Poseidon and Envisat Radar Altimetric Data

The Ku band backscatter coefficients data have been extracted since 2002.5 to 2005.5 from Topex/Poseidon(T/P)GDR-M and Envisat OPR datasets. Based on the continuous tension spline curve gridding method, the time series gridding data was obtained. Then the two different backscatter coefficients time series were compared. Carefully analysis and discussion on the spatial distribution characteristic of the backscattering coefficients in Inner Mongolia plateau, North China Plain, Northeast China Plain, the Qinghai Tibet Plateau, the Yunnan Guizhou Plateau, the Loess Plateau, the Yangtze River Plain indicate that both technologies can be used for monitoring natural disasters and potential environmental change of China and providing decision support for monitoring time series for land cover change