Nota sobre el significado lógico de ciertas estructuras residuadas elementales

Starting from an abelian grupoid which is ordered and residuated we study the logical significance of the 'residue' operation, specially if we add the most natural algebraic properties to the base structure, obtaining then several well-Known structures of mathematical logic, such as the deductively-complete algebras and the algebras of Sales,Hilbert,Abbott,Wajsberg and Boole .We also give some properties of the deductive systems and obtain an special version of the deduction theorem of Pla( [3] )

Geological, geochemical and mineralogical characteristics of REE-bearing Las Mercedes bauxite deposit, Dominican Republic

Bauxite deposits, traditionally the main source of 'aluminum, have been recently targeted for their remarkable contents in rare earth elements (REE). With Sigma REE (lanthanoids + Sc + Y) concentrations systematically higher than similar to 1400 ppm (ay. = 1530 ppm), the Las Mercedes karstic bauxites in the Dominican Republic rank as one of the REE-richest deposits of its style.The bauxitic ore in the Las Mercedes deposit is mostly unlithified and has a homogeneous-massive lithostructure, with only local cross-stratification and graded bedding. The dominant arenaceous and round-grained texture is composed of bauxite particles and subordinate ooids, pisoids and carbonate clasts. Mineralogically, the bauxite ore is composed mostly of gibbsite and lesser amounts of kaolinite, hematite, boehmite, anatase, goethite, chromian spinel and zircon. Identified REE-minerals include cerianite and monazite-Ce, whose composition accounts for the steady enrichment in light-relative to medium-and heavy-REE of the studied bauxites.Considering the paleo-geomorphology of the study area, we propose that bauxites in the Las Mercedes deposit are the product of the erosion and deposition of lithified bauxites located at higher elevations in the Bahoruco ranges. Based on the available data, we suggest a mixed lithological source for the bauxite deposits at the district scale: bedrock carbonates and an igneous source of likely mafic composition. (C) 2017 Elsevier B.V. All rights reserved

Phenolic profile and physicochemical characterization of quince (Cydonia oblonga Mill) fruits at different maturity index

The ripening of fruits is a determinant factor on the composition of phytochemical compounds such as phenolic compounds. In this study the phenolic profile of quince fruits was determined as a function of its maturity index. Based on the total soluble solids (TSS) and the acidity (TA) of the fruits, four maturity indexes were established (12.55, 14.56, 21.86 and 24.77), using the ratio of TSS/TA. The phenolic profile of quince fruits with different maturity indexes were obtained by a reversed-phase HPLC-DAD and HPLC-DAD/MS. A PCA loading plot was generated to explain the relationship between physicochemical parameters and the phenolic compounds. The phenolic compounds identified in the quince fruits were 3-0-caffeoylquinic acid, catechin, 4-0-caffeoylquinic acid, 5-0-caffeoylquinic acid, coumaric acid, quercetin-3-0-rutinoside and quercetin-3-0-glycosides. The maturity index increase caused in general a reduction of phenolic compounds, these compounds were also influenced by pH and acidity of fruits. Quince is a valuable source of natural phenolic antioxidants, and can be used as raw material to elaborate diverse food products, providing important functional properties

Single-institution experience in clinical trials during the COVID-19 pandemic in Spain: Not so bad after all?

The impact of the COVID-19 outbreak in Spain during March-April 2020 has been unbalanced throughout the different regions of the country. The alarm status defined by the government on March 14, and still in place at the time of this writing, has transformed the country in different perspectives, including care of patients with cancer.1 In many centers, clinical trial activity was suspended, because it was not considered a priority under the health care challenge of the COVID-19 pandemic.2 Nevertheless, experimental therapy is the only and/or best therapeutic option for many patients with cancer

An Overview of Microgrids Challenges in the Mining Industry

Indexación: Scopus.The transition from fossil fuels to renewable energies as power sources in the heavy industries is one of the main climate change mitigation strategies. The carbon footprint in mining is related to its inherent extraction process, its high demand of electric power and water, and the use of diesel. However, considering its particular power requirements, the integration of microgrids throughout the whole control hierarchy of mining industry is an emergent topic. This paper provides an overview of the opportunities and challenges derived from the synergy between microgrids and the mining industry. Bidirectional and optimal power flow, as well as the integration of power quality have been identified as microgrid features that could potentially enhance mining processes. Recommendations pertaining to the technological transition and the improvement of energy issues in mining environments are also highlighted in this work.https://ieeexplore.ieee.org/document/9229426

Socioeconomic Factors and All Cause and Cause-Specific Mortality among Older People in Latin America, India, and China: A Population-Based Cohort Study

Cleusa Ferri and colleagues studied mortality rates in over 12,000 people aged 65 years and over in Latin America, India, and China and showed that chronic diseases are the main causes of death and that education has an important effect on mortality

A western route of prehistoric human migration from Africa into the Iberian Peninsula

Being at the western fringe of Europe, Iberia had a peculiar prehistory and a complex pattern of Neolithization. A few studies, all based on modern populations, reported the presence of DNA of likely African origin in this region, generally concluding it was the result of recent gene flow, probably during the Islamic period. Here, we provide evidence of much older gene flow from Africa to Iberia by sequencing whole genomes from four human remains from northern Portugal and southern Spain dated around 4000 years BP (from the Middle Neolithic to the Bronze Age). We found one of them to carry an unequivocal sub-Saharan mitogenome of most probably West or West-Central African origin, to our knowledge never reported before in prehistoric remains outside Africa. Our analyses of ancient nuclear genomes show small but significant levels of sub-Saharan African affinity in several ancient Iberian samples, which indicates that what we detected was not an occasional individual phenomenon, but an admixture event recognizable at the population level. We interpret this result as evidence of an early migration process from Africa into the Iberian Peninsula through a western route, possibly across the Strait of Gibraltar