Procedimiento de preparación de derivados de tipo arilo-heteroarilo y arilo-arilo y compuestos obtenidos

El objeto de la presente invención es un procedimiento de preparación de derivados de tipo arilo — heteroarilo y arilo - arilo a partir de anilinas o sales de diazonio y de compuestos aromáticos, que pueden ser arilos o heteroarilo, en el cual se utilizan materiales que aportan ácido ascórbico o sus derivados como catalizadores. Constituyen igualmente un objeto de la presente invención los compuestos obtenidos mediante el referido procedimiento.Peer reviewedConsejo Superior de Investigaciones CientíficasA1 Solicitud de adición a la patent

Molecular Simplification in Bioactive Molecules: Formal Synthesis of (+)-Muconin

7 páginas, 1 figura, 7 esquemas, 1 tabla.-- El PDF es la versión post-print.The concept of molecular simplification as a drug design strategy to shorten synthetic routes, while keeping or enhancing the biological activity of the lead drug, has been applied to (+)-muconin, an acetogenin with remarkable cytotoxicity. A novel approach that enables the stereoselective synthesis of such a natural compound or its enantiomer from a common precursor is described. An additional advantage of the method is complete stereochemical control and the decrease in the number of chemical steps required, thus providing an enhancement of the overall yield. Antiproliferative studies against the human solid tumor cell lines showed that the aliphatic chain-THF/THP fragment of (+)-muconin has modest cytotoxic activity. The strategy opens the way to preparing novel bioactive acetogenin analogues by shorter synthetic routes.The authors thank the MYCT (PPQ2002- 04361-C04-02) of Spain and the Canary Islands Government for supporting this research. F.R.P.C. thanks CajaCanarias for a FPI fellowship. R.C. thanks the Spanish MEC for a FPU fellowship. J.M.P. thanks ICIC for a postdoctoral fellowship.Peer reviewe

Online Coalition Formation under Random Arrival or Coalition Dissolution

Coalition formation considers the question of how to partition a set of $n$ agents into disjoint coalitions according to their preferences. We consider a cardinal utility model with additively separable aggregation of preferences and study the online variant of coalition formation, where the agents arrive in sequence and whenever an agent arrives, they have to be assigned to a coalition immediately. The goal is to maximize social welfare. In a purely deterministic model, the greedy algorithm, where an agent is assigned to the coalition with the largest gain, is known to achieve an optimal competitive ratio, which heavily relies on the range of utilities. We complement this result by considering two related models. First, we study a model where agents arrive in a random order. We find that the competitive ratio of the greedy algorithm is $\Theta\left(\frac{1}{n^2}\right)$, whereas an alternative algorithm, which is based on alternating between waiting and greedy phases, can achieve a competitive ratio of $\Theta\left(\frac{1}{n}\right)$. Second, we relax the irrevocability of decisions by allowing to dissolve coalitions into singleton coalitions, presenting a matching-based algorithm that once again achieves a competitive ratio of $\Theta\left(\frac{1}{n}\right)$. Hence, compared to the base model, we present two ways to achieve a competitive ratio that precisely gets rid of utility dependencies. Our results also give novel insights in weighted online matching.Comment: Appears in the 31st Annual European Symposium on Algorithms (ESA 2023

“Knowledge and Utilisation of Information and Communication Technology (ICT) in Agricultural Sector, its Problems and Prospects- A Study in Upper Brahmaputra Valley Zone of Assam, India”

Agriculture is different from other industry and it plays a vital role in the economic development of a country. In a country like India, its prosperity depends upon the development of agricultural. There are different sorts of agricultural products that have been produced in India and therefore the production and marketing of these farm products is quite difficult. Awareness of farmers regarding different methods of production, components of market information and its utility is generally verypoor with compared to the traders. In this context, Information and communication technologies (ICTs) have a great role to change the existing traditional agricultural system in developing countries. An attempt is made to study the relationship between various socio-economic factors and knowledge and utilization of ICT in agricultural sector in Upper Brahmaputra Valley Zone of Assam. Apart from these, problems and prospects of using ICT in agricultural sector is also analysed in the study area. Through application of ICTs in agriculture it is possible to; make efficient information dissemination, bring precision agriculture, production decision and increase market access of farmers.  Now-a-days, most of the farmers of developing countries majority of rural farmers’ have access to ICT tools. However, most of the farmers have no enough awareness on the significance role of ICTs for agricultural production and its subsequent impact on welfare improvement. It is found that age and farm experience, extension contact and agricultural enterprise are negatively associated with knowledge and utilization of ICT among farmers. On the other hand, education, land holding, income and mass media participation are found to have positive correlation with knowledge and utilization of ICT among farmers. Lack of awareness, lack of reliable content in vernacular medium and high cost are some significant constraints of using ICT in agriculture. Therefore, proper training, provision of adequate training channelizing ICT to farmers through farmers organization can enhance the use of ICT in agricultur