National Trends on Agricultural Crops Production: Cluster Analysis

Staring from descriptive data on crop production and cultivated area at national level during on fifteen years, the aim of this study is to reveal the trends on crops cultivation. The cluster analysis reveals linkages between crops classes as well as between different crops, which can be partly assigned to crops rotation. Time series analysis reveals dramatically reducing of production of some crops, such as flax, hemp, and sugar beet, and increasing of production, such at sunflower, and increasing of productivity, such at potatoes and field vegetables

Generalized high-order iterative methods for solutions of nonlinear systems and their applications

In this paper, we have constructed a family of three-step methods with sixth-order convergence and a novel approach to enhance the convergence order $p$ of iterative methods for systems of nonlinear equations. Additionally, we propose a three-step scheme with convergence order $p+3$ (for $p\geq3$) and have extended it to a generalized $(m+2)$-step scheme by merely incorporating one additional function evaluation, thus achieving convergence orders up to $p+3m$, $m\in\mathbb{N}$. We also provide a thorough local convergence analysis in Banach spaces, including the convergence radius and uniqueness results, under the assumption of a Lipschitz-continuous Fréchet derivative. Theoretical findings have been validated through numerical experiments. Lastly, the performance of these methods is showcased through the analysis of their basins of attraction and their application to systems of nonlinear equations

Molecular Descriptors Family on Vertex Cutting: Relationships between Acelazolamide Structures and their Inhibitory Activity

Aim: To investigate the relationship between the structural information of acetazolamides and their inhibitory activity on carbonic anhydrase II. Material and Method: A sample of previously reported acetazolamides was studied. A pool of descriptors was calculated based on matrix representation and vertex cut in order to be included in the multiple linear regression analysis. The best performing model in terms of goodness-of-fit was analysed in order to assess its validity and reliability. The model was compared with previously reported models using a series of information and prediction criteria besides the Steiger’s Z test. Results: A model with a 99.77% determination coefficient proved to be the best performing model. The obtained model proved to have a less than 5% average of the absolute difference between the observed and the estimated inhibitory activity. The information and prediction criteria showed that the obtained model was better than the previously reported models. This conclusion is also sustained by the results of Steiger’s Z test (7.78; p = 3.66·10-15). Conclusion: The inhibitory activity on carbonic anhydrase II of acetazolamides proved to be of geometric and topologic nature and depended on the compounds’ melting point, relative atomic mass and atomic electronegativity