317 research outputs found
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
Simultaneous Phase Shifting Shearing Interferometry for Measurement of Static and Dynamic Phase Objects
Experimental Ï Phase-Shifts Observed in the Fourier Spectra of Phase Gratings and Applications in Simultaneous PSI
Apuntes para la historia de la Salud PĂșblica en el Municipio de Boyeros. Ciudad de la habana.
El municipio de Boyeros adquiriĂł su fisonomĂa actual, a partir de 1976, en que se estableciĂł la nueva divisiĂłn polĂtica administrativa. Es uno de los municipios de Ciudad Habana, tiene una extensiĂłn territorial de 134,2 km2 con una poblaciĂłn 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 PĂșblica es importante porque la memoria es una de las fuentes esenciales para la formaciĂłn de los valores que  identifican a los integrantes de un pueblo, de una naciĂłn, fundamentalmente a sus jĂłvenes. Por ello estos apuntes para la historia de la Salud PĂșblica del municipio Boyeros referirĂĄn los hitos mĂĄs significativos de ese proceso desde la Colonia hasta la actualidad.  Palabras clave: Municipio de Boyeros, historia, Salud PĂșblic
Marina Samuel Noble, gloria del deporte cubano.
En 1984, ingresa al claustro de profesores del Instituto Superior de Ciencias MĂ©dicas de La Habana una joven mujer de pequeña estatura, jovial y dinĂĄmica, respetada y querida por todos, La gacela de MorĂłn, atleta de renombre nacional e internacional de nuestro paĂs. 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, tĂ©rmino municipal de MorĂłn; sus padres Alfredo y Luisa trabajadores del campo, de nacionalidad jamaicana. Crece rodeada de limitaciones econĂłmicas. Con solo 11 años participa activamente en las tareas de la RevoluciĂłn, alfabetiza y se integra a los CDR y la FMC
Simultaneous Phase Shifting Shearing Interferometry for Measurement of Static and Dynamic Phase Objects
Exchange Rules for Diradical Ï-Conjugated Hydrocarbons
A variety of planar Ï-conjugated hydrocarbons such as heptauthrene, Clarâs 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 Hundâs 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 Liebâs theorem and Ovchinnikovâs 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 âFundaçaÌo para a CieÌncia e a Tecnologiaâ (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 âFundaçaÌo para a CieÌncia e a Tecnologiaâ (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 Unionâs 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 RamĂłn 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-MartĂnez. 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 âNextGenerationEUâ
program supporting the âMargarita Salasâ 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
(nÂș 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
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