Pd-catalyzed Arylation of 1,2-Amino Alcohol Derivatives via beta-Carbon Elimination

Herein, we describe a Pd-catalyzed arylation of 1,2-amino alcohols with aryl halides enabled by a retroallylation manifold. This protocol constitutes a new entry point to beta-arylated aldehydes via the intermediacy of in situ generated enamine intermediates. The protocol is characterized by its exquisite regioselectivity profile and broad substrate scope – including challenging substrate combinations –, even in an enantioselective manner

Market Entry, Fighting Brands, and Tacit Collusion: Evidence from the French Mobile Telecommunications Market

We study a major new entry in the French mobile telecommunications market, followed by the introduction of fighting brands by the three incumbents. Using an empirical oligopoly model, we find that the incumbents’ fighting brand strategies are difficult to rationalize as unilateral best responses. Instead, their strategies are consistent with a breakdown of tacit semi-collusion: before entry, the incumbents could successfully coordinate on restricting product variety to avoid cannibalization; after entry, this outcome became harder to sustain because of increased business stealing incentives. Consumers gained considerably from the added variety and, to a lesser extent, from the incumbents’ price responses. (JEL L13, L21, L96, M31)

Machine Learning Method to Differentiate Ataxias

Spinocerebellar ataxias or SCAs, are a group of more than 37 genetically and clinically heterogeneous known neurodegenerative diseases. This work analyzes the level of genetic similarity between several ataxias, we identified proteins that are associated with more than one ataxia. A decision tree was trained to identify ataxias by identifying whether a new entry disease not yet identified and not classified can be grouped as an ataxia. Altogether 12 proteins from different ataxias were verified, all 12 proteins were analyzed in 500 different trees to better evaluate the method used. Of the 12 proteins tested, the method was correct for 10 different proteins or 83% of correct results. This identifier and the results obtained in the experiments allow a greater characterization of the diseases addressed, it also allows applications such as the reuse of treatments for similar diseases.

State-operator correspondence in celestial conformal field theory

The bulk-to-boundary dictionary for 4D celestial holography is given a new entry defining 2D boundary states living on oriented circles on the celestial sphere. The states are constructed using the 2D CFT state-operator correspondence from operator insertions corresponding to either incoming or outgoing particles which cross the celestial sphere inside the circle. The BPZ construction is applied to give an inner product on such states whose associated bulk adjoints are shown to involve a shadow transform. Scattering amplitudes are then given by BPZ inner products between states living on the same circle but with opposite orientations. 2D boundary states are found to encode the same information as their 4D bulk counterparts, but organized in a radically different manner.

Benchmarking is a method for developing educational institutions: المقارنة المرجعية أسلوب لتطوير المؤسسات التعليمية

The study aimed to highlight the theoretical and intellectual foundations of the importance of benchmarking as a new entry point for the development of educational institutions through taking advantage of competing partners in the educational field. The study used the documentary descriptive approach leading to a set of results, including: The diversity of benchmarking patterns provides an opportunity to benefit from them in educational institutions, and determining the requirements for the application of benchmarking in each institution based on its specific need which differs from one institution to another, in addition to many benefits that are greatly beneficial to educational institutions that apply benchmarking with quality and professionalism. The study provided a set of recommendations; Most notably: building partnerships based on development and improvement through the application of benchmarking as it is an effective tool to gain benefit from distinguished institutions locally and internationally. It is also possible to employ (classification and academic accreditation) obtained by educational institutions to reach the comparative partner easily and in accessible way.