MTA-SZTE Research Group on Artificial Intelligence
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Estimation of the Spatiotemporal Variability of Surface soil Moisture Using Machine Learning Methods Integrating Satellite and Ground-based Soil Moisture and Environmental Data
Get PDFMonitoring and quantifying the development of drought extremes is important to agriculture, water, and land management. For this, soil moisture (SM) is an effective indicator. However, currently, real-time monitoring and forecasting of SM is challenging. Thus, this study develops and tests a methodology based on machine learning methods that integrates ground-based data, Sentinel-1 satellite soil moisture (S1SSM) data, meteorological data, and relevant environmental parameters to improve the estimation of the spatiotemporal changes in SM. It also evaluates the relevance of the applied parameters and the applicability and limitations of S1SSM data in SM monitoring. Specifically, the performances of four machine learning methods (multiple linear regression, support vector machine regression, extreme gradient boosting, and a deep neural network) were evaluated in an area increasingly exposed to hydrological extremes. Overall, the extreme gradient boosting model provided the best result (R 2 = 0.92). In this case, the difference between the modeled and observed SM values at ground-based stations was below 3%, with only five stations reporting differences above 5%, indicating the effectiveness of this model for SM monitoring in larger areas. Additionally, the spatial pattern of the observed S1SSM values and the modeled values showed good agreement (with a difference below 10%) in the larger part (45.5%) of the area, while more than 20% difference occurred in 27.1% of the area, demonstrating the application potential of S1SSM data in areas with less heterogeneous land use. However, the results also suggest that the S1SSM data can be affected by land use and/or soil types
Age-dependent changes in NMDA-induced excitotoxicity and neuromodulatory effects of kynurenic acid and its analogue in mouse brain slices
Get PDFKynurenic acid (KYNA) is one of the main neuroprotective substances of the kynurenine pathway. KYNA plays an important role in various neurodegenerative and psychiatric diseases. Although KYNA has been shown to have neuroprotective effects, it cannot be used as a peripherally administered drug due to its poor ability to cross the blood-brain barrier. To address this limitation, chemically modified KYNA analogues are being developed: SZR72 is one such analogue and has been shown to be protective in various animal models. Glutamate-induced excitotoxicity is a key factor in many neurodegenerative diseases. Therefore, we used the N-methyl-D-aspartate (NMDA)-induced excitotoxicity model to investigate the neuromodulatory agents. Using acute hippocampal slices from mouse brains, we investigated the potential neuroprotective effect of KYNA and its analogue, SZR72 on NMDA-induced excitotoxicity across different age groups of mice. The degree of tissue damage was assessed using biochemical and histological methods. In young animals (1- and 4-week-old), NMDA treatment caused no significant changes, and the cells were found to be resistant. However in older animals (8-week-old and 1-year-old), NMDA caused significant damage in cells and tissue structure, which was reduced by KYNA and SZR72 treatment. To our knowledge, this is the first study to compare the neuroprotective effects of KYNA and SZR72 in animals of different ages using an in vitro NMDA excitotoxicity model
Simplified Visual Stimuli Impair Retrieval and Transfer in Audiovisual Equivalence Learning Tasks
Get PDFBackgroundThe visually guided Rutgers Acquired Equivalence Test (RAET) and the various visual and audiovisual versions of the test with the same structure involve rule acquisition, retrieval, and generalization and is based on learning stimulus pairs (antecedents and consequents). In an earlier study we have found no difference in the acquisition learning and only slight enhancement in retrieval and generalization in the audiovisual learning compared to the visual one if complex readily verbalizable visual stimuli (cartoon faces and color fish) were used. In this study, we sought to examine whether similar phenomena can be observed with feature-restricted, less verbalizable visual stimuli (geometric shapes).MethodsA total of 119 healthy adult volunteers completed two computer-based test paradigms: Polygon (PO) and SoundPolygon (SP). PO is a visual test where the antecedents are shaded circles, and the consequents are geometric shapes. SP is an audiovisual test where the antecedents are sounds and the consequents are the same geometric shapes as in PO.ResultsThere were no significant differences in the performances and the reaction times in the acquisition phase between the PO (visual) and SP (audiovisual) tests. However, the performances in retrieval and generalization were significantly poorer in the audiovisual test and the reaction times were also longer.ConclusionThe acquisition phase seems to be independent from the stimulus modality if the simple geometric shapes were visual stimuli. However, feature-restricted, less verbalizable visual stimuli make more difficult to retrieve and generalize the already acquired audiovisual information
Quantitative characterization of the lateral distribution of gold nanoparticles in polystyrene nanocomposite thin films by laser-induced breakdown spectroscopy elemental mapping
No full textSynthesis and Antiproliferative Effects of Grossheimin-Derived Aminoanalogues
Get PDFGrossheimin, a guaiane-type sesquiterpene lactone, displayed a diverse range of biological activities, including anticancer, anti-inflammatory and antimicrobial effects. Various amino analogues of grossheimin were prepared through a Michael addition at its highly active α-methylene-γ-lactone motif. On the other hand, grossheimin was reduced to diol, which was then subjected to nucleophilic addition or acetylation to introduce heteroatoms associated with oxygen, sulfur or nitrogen functionalities. All of the synthesised Michael and acetylated adducts were evaluated for their in vitro cytotoxic action on human colon adenocarcinoma lines, including Colo205 and Colo320. The bioassay results indicated that the acetylated adducts displayed a potent cytotoxic effect compared to grossheimin, the parent molecule. A docking study was also performed to exploit the observed results
Distinct expression of NEAT1 isoforms in Parkinson's disease models suggests different roles of the variants during the disease course
Get PDFParkinson's disease (PD) is the second most common neurodegenerative disease worldwide. Recently long non-coding RNAs (lncRNAs) have emerged as possible molecular hubs in the diverse pathomechanisms of the disease. Among them, NEAT1 gained particular interest due to findings suggesting both protective and deleterious effects of this lncRNA in PD models.The aim of this study was to clarify some of the contradictions among data that appeared in recent publications concerning NEAT1 effects. For this, we determined whether pharmacological increase of NEAT1 levels worsened the detrimental effect of MPP + in the SH-SY5Y cell model, and whether the levels of the short and long isoform of the lncRNA changed differently upon short and extended MPTP treatment in an MPTP-induced mouse model of PD. Our findings suggest differential expression of NEAT1/Neat1 isoforms in MPP + /MPTP-induced PD models, which is in accord with the proposed role of the lncRNA in the general stress response. We propose that first an early up-regulation of Neat1_2 is dominant. The level of Neat1_2 then decreases as pathology progresses, resulting in a shift in the ratio of the two isoforms towards a higher level of Neat1_1 accompanied by damage of the central nervous system
A tropical crop, as Hungarian farmers’ potential response to climate change – the sweet potato
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