71 research outputs found

    Density functional formalism in the canonical ensemble

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    Density functional theory, when applied to systems with T0T\neq 0, is based on the grand canonical extension of the Hohenberg-Kohn-Sham theorem due to Mermin (HKSM theorem). While a straightforward canonical ensemble generalization fails, work in nanopore systems could certainly benefit from such extension. We show that, if the asymptotic behaviour of the canonical distribution functions is taken into account, the HKSM theorem can be extended to the canonical ensemble. We generate NN-modified correlation and distribution functions hierarchies and prove that, if they are employed, either a modified external field or the density profiles can be indistinctly used as independent variables. We also write down the NN% -modified free energy functional and prove that its minimum is reached when the equilibrium values of the new hierarchy are used. This completes the extension of the HKSM theorem.Comment: revtex, to be submitted to Phys. Rev. Let

    Áreas potenciales para plantaciones de Agave angustifolia Haw en Guerrero, México

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    Objective: To determine optimum and suboptimal areas for the establishment of plantations of Agave angustifolia Haw. in the state of Guerrero. Design/methodology/approach: A collection of 139 specimens of A. angustifolia was carried out, obtaining for each specimen phenotypic, agroclimatic and agroecological data. The information of 30 specimens of herbarium was consulted. Interviews were conducted with the representatives of the state council of mezcal in Guerrero, the company Sanzekan Tinemi and Mezcalli del Sur, to complement the information of the areas. A database was created where the information of each copy was included, as well as the information obtained from the interviews. Criteria for selecting potential areas of A. angustifoliawere defined, after which a Geographic Information Systems (GIS) was constructed, generating mapping areas with agroclimatic and agro potential, wherein the optimal suboptimal and marginal areas for the establishment of A. angustifolia were delineated. For the validation of the information, field visits were made to specific sites to verify the agroecological conditions of the potential areas obtained in this research. Results: There are approximately 1,020,998.27 ha with optimum aptitude and 618,015.87 ha with suboptimal aptitude. Limitations on study/implications: We suggest to incorporate information referring to the physiology, productivity and genetic diversity of the native populations of A. angustifolia. Findings/conclusions: The regions with the highest and suboptimal potential for the plantations of A. angustifolia are Norte, Tierra Caliente and Centro, where the largest production of mezcal in the state occurs.  Objetivo: Determinar áreas optimas y subóptimas para establecer plantaciones de Agave angustifolia Haw. en el estado de Guerrero, México. Diseño/metodología/aproximación: Se recolectaron 139 ejemplares de A. angustifolia, para cada ejemplar se registraron datos fenotípicos, agroclimáticos y agroecológicos. Se consultó la información de 30 ejemplares de herbario; además se entrevistaron a los representantes del Consejo Estatal del Mezcal en Guerrero, la empresa Sanzekan Tinemi y la empresa Mezcalli del Sur, para complementar la información de las áreas. Se generó una base de datos donde se incluyó la información de cada ejemplar, así como la obtenida de entrevistas. Se definieron criterios para la selección de áreas potenciales de A. angustifolia, después de lo cual se construyó un Sistema de Información Geográfica (SIG),generando la cartografía de las áreas con potencial agroclimático y agroecológico, donde se delimitaron las áreas optimas, subóptimas y marginales, para el establecimiento de A. angustifolia. Para la validación de la información, se realizaron visitas de campo a sitios específicos para verificar las condiciones agroecológicas de las áreas potenciales obtenidas en el presente trabajo. Resultados: Los resultados indican que existen aproximadamente 1,020,998.27 ha con aptitud óptima y 618,015.87 ha con aptitud subóptima. Limitaciones del estudio/implicaciones: se sugiere incorporar información referente a la fisiología, productividad y diversidad genética de las poblaciones nativas de A. angustifolia. Hallazgos/conclusiones: Las regiones con mayor potencial optimo y subóptimo para las plantaciones de A. angustifolia son Norte, Tierra Caliente y Centro, donde además se presenta la mayor producción de mezcal en el estado

    Characterization of S3Pvac Anti-Cysticercosis Vaccine Components: Implications for the Development of an Anti-Cestodiasis Vaccine

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    Background: Cysticercosis and hydatidosis seriously affect human health and are responsible for considerable economic loss in animal husbandry in non-developed and developed countries. S3Pvac and EG95 are the only field trial-tested vaccine candidates against cysticercosis and hydatidosis, respectively. S3Pvac is composed of three peptides (KETc1, GK1 and KETc12), originally identified in a Taenia crassiceps cDNA library. S3Pvac synthetically and recombinantly expressed is effective against experimentally and naturally acquired cysticercosis.Methodology/ Principal Findings: In this study, the homologous sequences of two of the S3Pvac peptides, GK1 and KETc1, were identified and further characterized in Taenia crassiceps WFU, Taenia solium, Taenia saginata, Echinococcus granulosus and Echinococcus multilocularis. Comparisons of the nucleotide and amino acid sequences coding for KETc1 and GK1 revealed significant homologies in these species. The predicted secondary structure of GK1 is almost identical between the species, while some differences were observed in the C terminal region of KETc1 according to 3D modeling. A KETc1 variant with a deletion of three C-terminal amino acids protected to the same extent against experimental murine cysticercosis as the entire peptide. on the contrary, immunization with the truncated GK1 failed to induce protection. Immunolocalization studies revealed the non stage-specificity of the two S3Pvac epitopes and their persistence in the larval tegument of all species and in Taenia adult tapeworms.Conclusions/ Significance: These results indicate that GK1 and KETc1 may be considered candidates to be included in the formulation of a multivalent and multistage vaccine against these cestodiases because of their enhancing effects on other available vaccine candidates

    Type 2 Diabetes Variants Disrupt Function of SLC16A11 through Two Distinct Mechanisms

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    Type 2 diabetes (T2D) affects Latinos at twice the rate seen in populations of European descent. We recently identified a risk haplotype spanning SLC16A11 that explains ∼20% of the increased T2D prevalence in Mexico. Here, through genetic fine-mapping, we define a set of tightly linked variants likely to contain the causal allele(s). We show that variants on the T2D-associated haplotype have two distinct effects: (1) decreasing SLC16A11 expression in liver and (2) disrupting a key interaction with basigin, thereby reducing cell-surface localization. Both independent mechanisms reduce SLC16A11 function and suggest SLC16A11 is the causal gene at this locus. To gain insight into how SLC16A11 disruption impacts T2D risk, we demonstrate that SLC16A11 is a proton-coupled monocarboxylate transporter and that genetic perturbation of SLC16A11 induces changes in fatty acid and lipid metabolism that are associated with increased T2D risk. Our findings suggest that increasing SLC16A11 function could be therapeutically beneficial for T2D. Video Abstract [Figure presented] Keywords: type 2 diabetes (T2D); genetics; disease mechanism; SLC16A11; MCT11; solute carrier (SLC); monocarboxylates; fatty acid metabolism; lipid metabolism; precision medicin

    Is diet partly responsible for differences in COVID-19 death rates between and within countries?

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    Correction: Volume: 10 Issue: 1 Article Number: 44 DOI: 10.1186/s13601-020-00351-w Published: OCT 26 2020Reported COVID-19 deaths in Germany are relatively low as compared to many European countries. Among the several explanations proposed, an early and large testing of the population was put forward. Most current debates on COVID-19 focus on the differences among countries, but little attention has been given to regional differences and diet. The low-death rate European countries (e.g. Austria, Baltic States, Czech Republic, Finland, Norway, Poland, Slovakia) have used different quarantine and/or confinement times and methods and none have performed as many early tests as Germany. Among other factors that may be significant are the dietary habits. It seems that some foods largely used in these countries may reduce angiotensin-converting enzyme activity or are anti-oxidants. Among the many possible areas of research, it might be important to understand diet and angiotensin-converting enzyme-2 (ACE2) levels in populations with different COVID-19 death rates since dietary interventions may be of great benefit.Peer reviewe

    Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

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    The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

    Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19

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    Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe

    Nrf2-interacting nutrients and COVID-19 : time for research to develop adaptation strategies

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    There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPAR gamma:Peroxisome proliferator-activated receptor, NF kappa B: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2 alpha:Elongation initiation factor 2 alpha). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT(1)R axis (AT(1)R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity

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