Relating correlation measures: the importance of the energy gap

The concept of correlation is central to all approaches that attempt the description of many-body effects in electronic systems. Multipartite correlation is a quantum information theoretical property that is attributed to quantum states independent of the underlying physics. In quantum chemistry, however, the correlation energy (the energy not seized by the Hartree-Fock ansatz) plays a more prominent role. We show that these two different viewpoints on electron correlation are closely related. The key ingredient turns out to be the energy gap within the symmetry-adapted subspace. We then use a few-site Hubbard model and the stretched H$_2$ to illustrate this connection and to show how the corresponding measures of correlation compare.Comment: 6 pages, 3 figure

Análisis del empleo de barros boratados como materia prima para la construcción

El boro en exceso es perjudicial para la actividad agrícola. Las empresas productoras de ácido bórico ubicadas en el Valle de Lerma, Salta, emplean ulexita y ácido sulfúrico, dejando una cantidad importante de colas de procesos acumuladas en diques impermeabilizados. Trabajos previos demostraron la posibilidad de emplear dichas colas como materia prima para la obtención de nuevos productos cocidos. En este trabajo se estudia el empleo de colas como materia prima única y con agregado de cal, en la fabricación de materiales de construcción. Se determinaron propiedades físicas (% contracción lineal y resistencia mecánica) y la solubilidad del contaminante (boro) en agua.Boron excess is harmful for farm activities. Boric acid producers placed in Valle de Lerma, Salta, use ulexite and sulphuric acid as raw materials, putting a significant tailing amount aside. Previous research has shown the possibility of using boric acid process tailings as raw materials for the manufacture of new roasted products. The use of tailings as one-on-a-kind raw material or combined with lime for the manufacture of building bricks is presented in this paper. Physical properties (shrinking and mechanical resistance) and the solubility of boron were measured.Fil: Flores, Horacio Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Salta. Instituto de Investigación Para la Industria Química (i); Argentina. Universidad Nacional de Salta. Facultad de Ingenieria; ArgentinaFil: Mattenella, Lilian Ester. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Salta. Instituto de Investigación Para la Industria Química (i); Argentina. Universidad Nacional de Salta. Facultad de Ingenieria; ArgentinaFil: Valdez, Silvana Karina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Salta. Instituto de Investigación Para la Industria Química (i); Argentina. Universidad Nacional de Salta. Facultad de Ingenieria; ArgentinaFil: Riveros, Adolfo N.. Universidad Nacional de Salta. Facultad de Ingenieria. Escuela de Ingenieria Quimica; ArgentinaFil: Kwok, L. Universidad Nacional de Salta. Consejo de Investigacion; Argentin

Hierarchical Spatial Organization of Geographical Networks

In this work we propose the use of a hirarchical extension of the polygonality index as a means to characterize and model geographical networks: each node is associated with the spatial position of the nodes, while the edges of the network are defined by progressive connectivity adjacencies. Through the analysis of such networks, while relating its topological and geometrical properties, it is possible to obtain important indications about the development dynamics of the networks under analysis. The potential of the methodology is illustrated with respect to synthetic geographical networks.Comment: 3 page, 3 figures. A wokring manuscript: suggestions welcome

Feasibility and impact of online HIV/STI screening addressed to men who have sex with men and transgender women users of pre-exposure prophylaxis (PrEP) in Spain (TESTATE PrEP): a study protocol for a non-blinded randomised controlled trial

HIV & AIDS; Clinical trial; Sexually transmitted diseaseVIH y SIDA; Ensayo clínico; Enfermedad de transmisión sexualVIH i sida; Assaig clínic; Malaltia de transmissió sexualIntroduction The objectives of the study are: to design and implement a pilot intervention to offer self-sampling kits to detect HIV, Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and Treponema pallidum (TP) among gay, bisexual and other men who have sex with men and transgender women users of pre-exposure prophylaxis (PrEP) as part of PrEP follow-up. To evaluate if the pilot intervention causes a reduction of the retention to PrEP follow-up among the target population. To analyse the capacity of the intervention to reduce the healthcare burden on the PrEP service. To evaluate the acceptability of the intervention among PrEP users and PrEP service healthcare workers and; to validate dried blood samples for treponemal and non-treponemal antibody detection using the Dual Path Platform syphilis screening and confirmatory assay compared with blood drawn by venous puncture. Methods and analysis We will perform a non-blinded randomised controlled non-inferiority trial among PrEP users on follow-up. Participants on the control arm will follow the usual follow-up protocol with quarterly face-to-face visits where they will be tested for HIV and sexually transmitted infections (STIs). Participants in the experimental arm will alternate face-to-face meetings with online screening of HIV and STIs. The website https://testate.org/ will include a module for online follow-up visits of participants. Participants of the experimental arm will order self-sampling kits for HIV, CT, NG and TP through the website, will send the samples to the laboratory and check their results online. We will compare the retention to follow up and the healthcare burden in both arms. The acceptability of the intervention among participants and healthcare workers will be assessed. Ethics and dissemination The project has been approved by the CEIC-HUGTIP (Reference: PI-22-051). Subjects will be included after giving their informed consent. Final conclusions and recommendations will be shared with stakeholders. Two publications in peer-reviewed journals are expected. Trial registration number NCT05752643.This work was supported by the Instituto de Salud Carlos III (PI21/01589) and the Ministry of Health of the Government of Catalonia (Spain) (no grant number)

Determinación de los índices de salud nutricional de la leche fresca de bovino mediante espectroscopía de infrarrojo cercano

Bovine milk is one of the most complete foods that exist. During the last decades, milk FA have shown to improve human health due to the reduction in risk of cardiovascular disease and related pathologies. The aim of this study was to evaluate the feasibility of near infrared spectroscopy (NIRS) reflectance analysis to predict the nutritional value, fatty acid (FA) composition, and health index of fresh milk from dairy cows of pastoral systems. The prediction of Atherogenicity and Thrombogenicity indexes, along with other FA ratios in fresh milk samples by NIRS were precise and accurate. In addition, the calibration model obtained by NIRS provides an opportunity for the routine quantification of milk’s healthy FA such as omega-3 and conjugated linoleic acid (CLA), with applications in the dairy industry for food labeling, and at the farm level for management of the dairy cow’s diet.La leche bovina es uno de los alimentos más completos que existe. Durante la última década, se ha demostrado que los ácidos grasos de la leche pueden mejorar la salud humana, a través de la reducción del riesgo de enfermedades cardiovasculares y patologías asociadas. El objetivo de este estudio fue evaluar la factibilidad del análisis de reflectancia NIRS para predecir valor nutricional, composición de ácidos grasos e índices de salud de leche fresca de vacas de sistemas lecheros pastoriles. La predicción por NIRS del índice aterogénico y trombogénico, de ácidos grasos en muestras de leche fresca, fueron precisos. Por tanto, el modelo de calibración obtenido por NIRS representa una oportunidad para la cuantificación rutinaria de los ácidos grasos saludables de la leche como omega-3 y CLA, con aplicaciones en la industria lechera para el etiquetado nutricional y a nivel de lechería para el manejo de la alimentación de las vacas

Leucine-Rich Alpha-2-Glycoprotein as a non-invasive biomarker for pediatric acute appendicitis: a systematic review and meta-analysis

The aim of this study was to analyze the diagnostic performance of Leucine-Rich Alpha-2-Glycoprotein (LRG1) in pediatric acute appendicitis (PAA). We conducted a systematic review of the literature in the main databases of medical bibliography. Two independent reviewers selected the articles and extracted relevant data. Methodological quality was assessed using the QUADAS2 index. A synthesis of the results, standardization of the metrics and 4 random-effect meta-analyses were performed. Eight studies with data from 712 participants (305 patients with confirmed diagnosis of PAA and 407 controls) were included in this review. The random-effect meta-analysis of serum LRG1 (PAA vs control) resulted in a significant mean difference (95% CI) of 46.76 μg/mL (29.26–64.26). The random-effect meta-analysis for unadjusted urinary LRG1 (PAA vs control) resulted in a significant mean difference (95% CI) of 0.61 μg/mL (0.30–0.93). The random-effect metaanalysis (PAA vs control) for urinary LRG1 adjusted for urinary creatinine resulted in a significant mean difference (95% CI) of 0.89 g/mol (0.11–1.66). Conlusion: Urinary LRG1 emerges as a potential non-invasive biomarker for the diagnosis of PAA. On the other hand, due to the high between-study heterogeneity, the results on serum LRG1 should be interpreted with caution. The only study that analyzed salivary LRG1 showed promising results. Further prospective studies are needed to confirm these findings