Reduced mobility? Urban exodus? Medium-term impacts of the COVID-19 pandemic on internal population movements in Latin American countries

The COVID-19 pandemic has impacted the national systems of population movement around the world. Existing work has focused on countries of the Global North and restricted to the immediate effects of COVID-19 data during 2020. Data have represented a major limitation to monitor change in mobility patterns in countries in the Global South. Drawing on aggregate anonymised mobile phone location data from Meta-Facebook users, we aim to analyse the extent and persistence of changes in the levels (or intensity) and spatial patterns of internal population movement across the rural-urban continuum in Argentina, Chile and Mexico over a 26-month period from March 2020 to May 2022. We reveal an overall systematic decline in the level of short- and long-distance movement during the enactment of nonpharmaceutical interventions in 2020, with the largest reductions occurred in the most dense areas. We also show that these levels bounced back closer to pre-pandemic levels in 2022 following the relaxation of COVID-19 stringency measures. However, the intensity of these movements has remained below pre-pandemic levels in many areas in 2022. Additionally our findings lend some support to the idea of an urban exodus. They reveal a continuing negative net balances of short-distance movements in the most dense areas of capital cities in Argentina and Mexico, reflecting a pattern of suburbanisation. Chile displays limited changes in the net balance of short-distance movements but reports a net loss of long-distance movements. These losses were, however, temporary, moving to neutral and positive balances in 2021 and 2022.Comment: 29 pages, 5 figure

Plan de muestreo para estimar el consumo promedio de los usuarios del servicio público de acueducto del municipio de Pitalito – Huila

La Superintendencia de Servicios Públicos Domiciliarios – SSPD, dentro de su política de calidad evalúa la atención realizada por la entidad por medio de encuestas, cuyo resultado para el año 2015 fue procesado por Triviño (2016), destacándose dos aspectos interesantes como son las quejas por estrato y por servici

The use of computed tomography to explore the microstructure of materials in civil engineering: from rocks to concrete

Computed tomography (CT) is a nondestructive technique, based on absorbing X-rays, that permits the visualisation of the internal microstructure of material. The field of application is very wide. This is a well-known technology in medicine, because of its enormous advantages, but it is also very useful in other fields. Computed tomography is used in palaeontology to study the internal structure of the bones from ancient hominids. In addition, this technology is being used by engineers to analyse the microstructure of materials. Materials engineers use this technology to analyse or develop new materials. Mechanical engineers use CT scans to study the internal defects of materials. Geotechnical engineers use CT scans to study several aspects of the rocks and minerals (cracks, voids, etc). This technology is also very useful to study de microstructure of concrete, especially in case of the new concretes (ultra-high performance concrete, fiber reinforced concrete, etc). In this chapter, an extended state-of-the-art of the most relevant research, related to the use of computed tomography to explore the microstructure of materials in civil and mechanical engineering, is exposed. The main objective of this chapter is that the reader can discover new applications of the computed tomography, different from conventional ones

Unify Markov model for Rational Design and Synthesis of More Safe Drugs. Predicting Multiple Drugs Side Effects

The 9th International Electronic Conference on Synthetic Organic Chemistry session Computational ChemistryMost of present mathematical models for rational design and synthesis of new drugs consider just the molecular structure. In the present article we pretend extending the use of Markov Chain models to define novel molecular descriptors, which consider in addition other parameters like target site or biological effect. Specifically, this model takes into consideration not only the molecular structure but the specific biological system the drug affects too. Herein, it is developed a general Markov model that describes 19 different drugs side effects grouped in 8 affected biological systems for 178 drugs, being 270 cases finally. The data was processed by Linear Discriminant Analysis (LDA) classifying drugs according to their specific side effects, forward stepwise was fixed as strategy for variables selection. The average percentage of good classification and number of compounds used in the training/predicting sets were 100/95.8% for endocrine manifestations(18 out of 18)/(13 out of 14); 90.5/92.3% for gastrointestinal manifestations (38 out of 42)/(30 out of 32); 88.5/86.5% for systemic phenomena (23 out of 26)/(17 out of 20); 81.8/77.3% for neurological manifestations (27 out of 33)/(19 out of 25); 81.6/86.2% for dermal manifestations (31 out of 38)/(25 out of 29); 78.4/85.1% for cardiovascular manifestation (29 out of 37)/(24 out of 28); 77.1/75.7% for breathing manifestations (27 out of 35)/(20 out of 26) and 75.6/75% for psychiatric manifestations (31 out of 41)/(23 out of 31). Additionally a Back-Projection Analysis (BPA) was carried out for two ulcerogenic drugs to prove in structural terms the physic interpretation of the models obtained. This article develops a model that encompasses a large number of drugs side effects grouped in specifics biological systems using stochastic absolute probabilities of interaction (Apk (j)) by the first time

Luminescent cis-Bis(bipyridyl)ruthenium(II) Complexes with 1,2-Azolylamidino Ligands: Photophysical, Electrochemical Studies, and Photocatalytic Oxidation of Thioethers

Producción CientíficaNew 1,2-azolylamidino complexes cis-[Ru(bipy)2(NH═C(R)az*-κ2N,N)](OTf)2 (R = Me, Ph; az* = pz, indz, dmpz) are synthesized via chloride abstraction after a subsequent base-catalyzed coupling of a nitrile with the previously coordinated 1,2-azole. The synthetic procedure allows the easy obtainment of complexes having different electronic and steric 1,2-azoylamidino ligands. All of the compounds have been characterized by 1H, 13C, and 15N NMR and IR spectroscopy and by monocrystal X-ray diffraction. Photophysical studies support their phosphorescence, whereas their electrochemistry reveals reversible RuII/RuIII oxidations between +1.13 and +1.25 V (vs SCE). The complexes have been successfully used as catalysts in the photooxidation of different thioethers, the complex cis-[Ru(bipy)2(NH═C(Me)dmpz-κ2N,N)]2+ showing better catalytic performance in comparison to that of [Ru(bipy)3]2+. Moreover, the significant catalytic performance of the dimethylpyrazolylamidino complex is applied to the preparation of the drug modafinil, which is obtained using ambient oxygen as an oxidant. Finally, mechanistic assays suggest that the oxidation reaction follows a photoredox route via oxygen radical anion formation.Ministerio de Economía, Industria y Competitividad (grants PGC2018- 099470-B-I00 and RTI2018-095038-B-I00)Junta de Castilla y León (grant VA130618)Junta de Castilla y León - Fondo Social Europeo (project BU263P18

Effect of the heat treatment on the mechanical properties and microstructure of Scalmalloy® manufactured by Selective Laser Melting (SLM) under certified conditions

Mechanical properties and microstructure of Scalmalloy® processed by Selective Laser Melting (SLM) under certified conditions are studied. Two types of samples are considered: as-built and heat-treated at 325⁰C for 4 hours. The heat treatment does not modify the grain size or the texture. SEM images show a typical bi-modal microstructure comprising equiaxed fine grained zones (FGZ) with ≈ 0.6 micron grain size and coarse grained zones (CGZ) with ≈ 7.5 micron grain size (longitudinal axis). According to electron backscatter diffraction (EBSD) analysis, FGZ have ≈ 0.8 micron equivalent circle diameter (considering grain boundaries those with misorientation > 15⁰) and contain areas with and without texture, while CGZ have ≈ 2.7 micron equivalent circle diameter, and most of the grains are oriented with [001] crystal direction along the building direction. On the contrary, the heat treatment produces a stress relief that is evidenced in EBSD by reductions in the low angle grain boundaries (LAGB) content, grain orientation spread (GOS), and dislocation density. Both samples show plastic deformation before fracture and the as-built condition features Portevin-Le-Chatelier (PLC) effect. The heat-treated samples exhibit the highest strength (yield strength = 454 ± 3 MPa; tensile strength = 509 ± 6 MPa) and hardness (165 ± 3 HV) while the lowest percentage of reduction of area (16 ± 6%) and elongation (11 ± 2%). Finally, the electrical conductivity of the material increases after the heat treatment which is associated with the redistribution of Mg-atoms out of the solid solution and the growth of precipitate

T1b Glottic Tumor and Anterior Commissure Involvement: Is the Transoral CO2 Laser Microsurgery a Safe Option?

[Abstract] Objectives: Transoral CO2 laser therapy represents the treatment of choice for early-stage laryngeal tumors. The anterior commissure involvement (ACI) is related to a worse local control and a lower rates of organ preservation. The objective of this study is to analyze the differences in survival, local control, and organ preservation in T1b glottic patients according to the presence of ACI. Methods: Observational prospective study in pT1b treated with transoral CO2 laser between 2009 and 2014. Results: Forty patients (37 male and 3 female) with a mean age of 66.43 ± 8.16 years were recruited. Anterior commissure involvement was present in 70% of the patients. The 5-year specific cause survival was 91.66%, with 32.50% of local recurrences. Laryngeal preservation was 80%, being lower in the group with local recurrence (P < .000). The involvement of the anterior commissure does not influence the organ preservation (P = .548), the appearance of local recurrences (P = .391), or the survival (P = .33). Conclusions: Transoral CO2 laser therapy is an effective and reproducible treatment for early-stage laryngeal tumors. The results obtained are similar to previous studies, although they present discrepancies in relation to the role of the ACI. Prospective randomized trials are required focusing also on the patients’ quality of life and functional outcome in order to clarify the role of the ACI and the need to implement changes in its evaluation, staging, and evolution

Sistema universal de compresión excéntrica en probeta movible.

Sistema universal de comprensión excéntrica en probeta movible que aplica, sobre probetas de hormigón, una carga vertical controlada en magnitud y variable en posición, situada en un punto tal que cumpla con la condición deseada a priori, en términos de deformación vertical en la fibra de control. Para mover la posición que sobre la probeta presenta el punto de aplicación de la carga vertical se ha diseñado un sistema mecánico independiente del sistema de fuerza que permite mover horizontalmente la posición de la probeta en el interior del cuerpo de la máquina, sin interferir en el sistema de aplicación de carga vertical. Tanto el sistema de fuerza como el sistema de movimiento son gestionados por rutinas informáticas independientes sincronizadas, a través de las cuales se puede, no sólo gestionar el ensayo de acuerdo a los parámetros definidos a priori, sino medir, en todo instante de tiempo, una amplia serie de parámetros de ensayo.Solicitud: 200200583 (04.03.2002)Nº Pub. de Solicitud: ES2198205A1 (16.01.2004

Procedimiento de ensayo de compresión excéntrica en probetas de hormigón.

Procedimiento de ensayo de comprensión excéntrica en probetas de hormigón que tiene por objeto aplicar, sobre probetas de hormigón, una carga vertical creciente en magnitud y variable en posición, situada ésta en un punto tal que la deformación vertical en la región central de la fibra de control de una de las caras presente en todo momento un valor nulo y en la otra cara mida su valor. El ensayo se lleva a cabo en probetas de hormigón de cualquier dosificación, cualquier resistencia y cualquier edad. Se ha desarrollado para probetas de cuatro secciones tipo diferentes, a saber, rectangular, semicircular, triangular con deformación nula en arista y triangular con deformación nula en cara.Solicitud: 200200582 (04.03.2002)Nº Pub. de Solicitud: ES2195775A1 (01.12.2003)Nº de Patente: ES2195775B2 (16.11.2004