Interaction driven phases in the honeycomb lattice from exact diagonalization

We investigate the fate of interaction driven phases in the half-filled honeycomb lattice for finite systems via exact diagonalization with nearest and next nearest neighbour interactions. We find evidence for a charge density wave phase, a Kekul\'e bond order and a sublattice charge modulated phase in agreement with previously reported mean-field phase diagrams. No clear sign of an interaction driven Chern insulator phase (Haldane phase) is found despite being predicted by the same mean-field analysis. We characterize these phases by their ground state degeneracy and by calculating charge order and bond order correlation functions.Comment: 7 pages, 6 figures, updated reference

Apuntes para la historia de la Salud Pública en el Municipio de Boyeros. Ciudad de la habana.

El municipio de Boyeros adquirió su fisonomía actual, a partir de 1976, en que se estableció la nueva división política administrativa. Es uno de los municipios de  Ciudad Habana,  tiene una extensión territorial de 134,2 km2 con una población de 187006 habitantes, limita al Norte con el municipio Cerro, al Sur con los municipios Bejucal y San Antonio de los Baños de provincia Habana, al Este con el municipio Arroyo Naranjo y al Oeste con los municipios de La Lisa y de Marianao.  Es un municipio rico por su historia y tradiciones, acercarse a ellas y en particular a la historia del desarrollo de la Salud Pública es importante porque la memoria es una de las fuentes esenciales para la formación de los valores que  identifican a los integrantes de un pueblo, de una nación,  fundamentalmente a sus jóvenes. Por ello estos apuntes para  la historia de la Salud Pública del municipio Boyeros referirán los hitos más significativos de ese proceso desde la Colonia hasta la actualidad.   Palabras clave: Municipio de Boyeros, historia, Salud Públic

Marina Samuel Noble, gloria del deporte cubano.

En 1984, ingresa al claustro de profesores del Instituto Superior de Ciencias Médicas de La Habana una joven mujer de pequeña estatura, jovial y dinámica, respetada y querida por todos,  La gacela de Morón, atleta de renombre nacional  e internacional de nuestro país. Marina Samuel Noble nace el 14 de  diciembre de 1947 en el seno de una familia de origen campesino, en una colonia cañera del Central Punta Alegre, término municipal de Morón; sus padres Alfredo y Luisa trabajadores del campo, de nacionalidad jamaicana. Crece rodeada de limitaciones económicas.  Con solo 11 años participa activamente en las tareas de la Revolución, alfabetiza y  se integra a los CDR y la FMC

Exchange Rules for Diradical π-Conjugated Hydrocarbons

A variety of planar π-conjugated hydrocarbons such as heptauthrene, Clar’s goblet and, recently synthesized, triangulene have two electrons occupying two degenerate molecular orbitals. The resulting spin of the interacting ground state is often correctly anticipated as S = 1, extending the application of Hund’s rules to these systems, but this is not correct in some instances. Here we provide a set of rules to correctly predict the existence of zero mode states as well as the spin multiplicity of both the ground state and the low-lying excited states, together with their open- or closed-shell nature. This is accomplished using a combination of analytical arguments and configuration interaction calculations with a Hubbard model, both backed by quantum chemistry methods with a larger Gaussian basis set. Our results go beyond the well established Lieb’s theorem and Ovchinnikov’s rule, as we address the multiplicity and the open-/closed-shell nature of both ground and excited states.J.F.-R. and R.O. acknowledge financial support from MINECO-Spain (grant no. MAT2016-78625-C2) and from the Portuguese “Fundação para a Ciência e a Tecnologia” (FCT) for the project P2020-PTDC/FIS-NAN/4662/2014. J.F.-R., M.M.-F. and N.G.-M. acknowledge support from the P2020-PTDC/FISNAN/3668/2014. J.F.-R. acknowledges support from UTAPEXPL/NTec/0046/2017 projects as well as Generalitat Valenciana funding (Prometeo2017/139). R.O. and J.C.S.-G. acknowledge ACIF/2018/175 (Generalitat Valenciana and Fondo Social Europeo). M.M.-F. and R.B. acknowledge the Portuguese “Fundação para a Ciência e a Tecnologia” (FCT) for the project IF/00894/2015 and FCT ref. UID/CTM/50011/2019 for CICECO - Aveiro Institute of Materials. This project received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 664878

An Early Warning Method for Basic Commodities Price Based on Artificial Neural Networks

The prices of products belonging to the basic family basket are an important component in the income of producers and consumer spending; its excessive variations constitute a source of uncertainty and risk that affects producers, since it prevents the realization of long-term investment plans, and can refuse lenders to grant them credit. His study to identify these variations, as well as to detect their sources, is then of great importance. The analysis of the variations of the prices of the basic products over time, include seasonal patterns, annual fluctuations, trends, cycles and volatility. Because of the advance in technology, applications have been developed based on Artificial Neural Networks (ANN) which have helped the development of massive sales forecast on consumer products, improving the accuracy of traditional forecasting systems. This research uses the RNA to develop an early warning system for facing the increase in basic agricultural products, considering seasonal factors

Thermochemical characterization of eight seaweed species and evaluation of their potential use as an alternative for biofuel production and source of bioactive compounds

Algae are underexplored resources in Western countries and novel approaches are needed to boost their industrial exploitation. In this work, eight edible seaweeds were subjected to their valorization in terms of nutritional characterization, thermochemical properties, and bioactive profile. Our results suggest that seaweeds present a rich nutritional profile, in which carbohydrates are present in high proportions, followed by a moderate protein composition and a valuable content of !-3 polyunsaturated fatty acids. The thermochemical characterization of seaweeds showed that some macroalgae present a low ash content and high volatile matter and carbon fixation rates, being promising sources for alternative biofuel production. The bioactive profile of seaweeds was obtained from their phenolic and carotenoid content, together with the evaluation of their associated bioactivities. Among all the species analyzed, Porphyra purpurea presented a balanced composition in terms of carbohydrates and proteins and the best thermochemical profile. This species also showed moderate anti-inflammatory activity. Additionally, Himanthalia elongata extracts showed the highest contents of total phenolics and a moderate carotenoid content, which led to the highest rates of antioxidant activity. Overall, these results suggest that seaweeds can be used as food or functional ingredient to increase the nutritional quality of food formulations.The research leading to these results was supported by MICINN supporting the Ramón y Cajal grant for M.A. Prieto (RYC-2017-22891); by Xunta de Galicia for supporting the program EXCELENCIA-ED431F (1 December 2020), the post-doctoral grant of L. Cassani (ED481B- 2021/152), and the program Grupos de Referencia Competitiva (GRUPO AA1-GRC 2018) that supports the work of M. Barral-Martínez. The authors thank the program BENEFICIOS DO CONSUMO DAS ESPECIES TINTORERA-(CO-0019-2021) that supports the work of F. Chamorro. The research leading to these results was supported by the European Union through the “NextGenerationEU” program supporting the “Margarita Salas” grant awarded to P. Garcia-Perez. The authors are grateful to AlgaMar enterprise (www.algamar.com, accessed 30 December 2021) for the collaboration and algae material provision. The project SYSTEMIC Knowledge hub on Nutrition and Food Security has received funding from national research funding parties in Belgium (FWO), France (INRA), Germany (BLE), Italy (MIPAAF), Latvia (IZM), Norway (RCN), Portugal (FCT), and Spain (AEI) in a joint action of JPI HDHL, JPI-OCEANS and FACCE-JPI launched in 2019 under the ERA-NET ERA-HDHL (nº 696295).info:eu-repo/semantics/publishedVersio

Biological activities of Castela coccinea Griseb. extracts

Infusions of leaf and bark of Castela coccinea Griseb. (Simaroubaceae) were traditionally used against dysentery. In this work, anti-bacterial and antioxidant activity were studied in C. coccinea extracts. The higest DPPH scavenging activity was detected in ethanolic leaf extracts with an IC50= 0.015 mg/ml. Bark ethanolic extracts showed inhibition of lipoperoxidation and free radical scavenging. However, a previous work evidenced that this extract is toxic at a concentration needed to show antioxidant activity. It might be consider that wood could be used instead of bark extract as the first one showing higher scavenging activity (Wood 55 %, Bark 33 % of DPPH scavenging) and good inhibition of lipoperoxidation. It is a very interesting fact the high tannin and mucilage content, which are localized particularly in leaves. The high antioxidant activity and abundant mucilage and tannin contents could justify, at least in part, its popular use.Colegio de Farmacéuticos de la Provincia de Buenos Aire