Resistividad Electrica del Subsuelo del Volcan Galeras

Aplicando un método de electromagnetismo transitorio y utilizando un modelo de tierra plana de N capas, se obtiene un mapa de la resistividad eléctrica del subsuelo del anfiteatro del volcán Galera

EFFECT OF MESQUITE SEED GUM ON THE RHEOLOGICAL PROPERTIES OF MIXTURES WITH ARABIC AND GELLAN GUMS

ABSTRACT The mesquite seed gum (Prosopis sp.) represents an alternative application in the food industry, due to its structural likeness with other galactomannans used at the moment. The information about the properties of mesquite seed gum is scarce, for this is important to known the rheological properties of this biopolymer and its interactions with other polymers for seeing future applications. The aim of this work was study the rheological behavior of mesquite seed gum and their effects in arabic and gellan gum mixtures. They were prepared aqueous dispersions according to a Simplex-Centroid design, being obtained gum combinations of total concentration of 1% from mesquite-arabic, mesquite-gellan, arabic-gellan and mesquitearabic-gellan, the pH from the dispersions were adjusted to 4, 5 and 6. The mixtures as well as the individual biopolymers were dispersed to ambient temperature, and later heated during 20 minutes at 90 °C and cooling at 25 °C. The rheological studies were made using an Haake RV2 viscometer. The statistical analysis showed differences (a = 0.05) among the rheologic value for mixtures at different pH. The mixtures showed a nonNewtonian behavior, type pseudoplastic flow (shear thinning) and showed high viscosities to low shears rates (100 s l) in all the cases. The tendency of mixtures with two or three components showed an antagonistic effect in the viscosity. Particularly the mesquite seed gum suffers an antagonistic effect in the viscosity when it was mixed with the arabic and gellan gums, being observed decreases from a 8 until 45%, below the control

Challenges in the COVID-19 vaccination era: Prioritization of vaccines among essential workers in Mexico

The coronavirus disease-2019 (COVID-19) pandemic gave rise to a massive global health concern that has placed an unprecedented strain on healthcare systems, education and economy. The recent vaccine roll-out gave humanity a glimpse of hope. However, more than 50% of the vaccine supply has been acquired by high-income countries, forcing low- and middle-income countries to prioritize who should be vaccinated. In Mexico, the first phase of the vaccination program prioritized healthcare personnel working in front-line COVID-19 public institutions. The second phase was planned for the remaining healthcare workers attending at both COVID and non-COVID areas. The government, however, aiming to reopen schools, decided to vaccinate teachers instead. This raised several concerns, since Mexico tops the ranking of deaths among healthcare workers due to COVID-19 worldwide. Furthermore, the possible framing of vaccines as a political tool has caused commotion among the Mexican people and media, especially since 2021 is the Midterm Election year in Mexico, and the Teachers’ Union has historically played an essential role in this matter. Therefore, it is relevant to share the vaccination experience in resource-constrained settings to provide help and advice to reach an optimal strategy and deflate this pandemic

Physical impacts of the AD 1600 Huaynaputina VEI 6 eruption on habitat and infrastructure, southern Perù: Geophysical insights from the Huayruro project

The Huayruro project aims at better understanding the physical and socio-economic impacts of the CE 1600 Plinian eruption of Huaynaputina in south Peru (VEI 6, 11-14 km3 ). Despite its global climatic impact, its regional consequences on the Inca population and constructions have been scarcely studied. In particular, the location of ten to fifteen settlements buried by the erupted deposits is not accurately known. Finizola et al. (2018) identified several buried settlements and ruins during several archeological and geophysical surveys during the 2014-2017 period within a 16 km radius of the crater (Coporaque, Calicanto, and Chimpapampa). Extending their work in May 2018, we used ground- penetrating radar at 400 et 200 MHz, magnetic gradiometry, multi-frequency conductivimetry and Structure from Motion (SfM) photogrammetry with multi-view stereo to further explore the sites of Coporaque (12 km WSW of the crater), Estagagache (16 km SSE) and San Juan de Dios (17 km SW), affected by fallout deposits 2.6, 1.5 and 0.4 m thick, respectively. The present study provides spatial constraints for mapping buried house walls, cultivated terraces, rural infrastructure such as grain storage areas, contributing therefore to delineate the extent of the damaged villages. Such geophysical surveys combined with aerial imagery, high-spatial resolution DEMs and tephra studies help to focus on adequate sites for future archeological excavations and assess physical impacts of thick tephras and PDCs deposits on pre-Conquest constructions. The ultimate goal of the Huayruro project is to disseminate volcanic risk knowledge and help create one in situ museum to be built up on the site of Calicanto

Impacto de la erupción del volcán Huaynaputina del año 1600 d.C. en pueblos aledaños

El volcán Huaynaputina, en el sur de Perú, registró la erupción histórica más grande (VEI 6) en los Andes en el año 1600 d.C, la misma que sucedió durante la transición entre el Imperio Inca y el Virreinato del Perú. Este evento tuvo graves con secuencias en los Andes Centrales y un impacto climático global. Crónicas españolas informaron que existían al menos 15 aldeas o asentamientos alrededor del volcán, de los cuales siete de ellos fueron totalmente destruidos por la erupción. Los estudios multidisciplinarios que hemos implementado en los últimos años nos han permitido identificar y analizar las características de seis pueblos enterrados por la erupción. La caída de tefra y las corrientes de densidad piroclástica (PDCs), tuvieron impactos diferentes según la distancia del pueblo al cráter, la ubicación con respecto al emplazamiento de las PDCs a lo largo de los valles, las características geomorfológicas del sitio, y el tipo de construcciones

The efficacy of whole human genome capture on ancient dental calculus and dentin

Objectives: Dental calculus is among the richest known sources of ancient DNA in the archaeological record. Although most DNA within calculus is microbial, it has been shown to contain sufficient human DNA for the targeted retrieval of whole mitochondrial genomes. Here, we explore whether calculus is also a viable substrate for whole human genome recovery using targeted enrichment techniques. Materials and methods: Total DNA extracted from 24 paired archaeological human dentin and calculus samples was subjected to whole human genome enrichment using in-solution hybridization capture and high-throughput sequencing. Results: Total DNA from calculus exceeded that of dentin in all cases, and although the proportion of human DNA was generally lower in calculus, the absolute human DNA content of calculus and dentin was not significantly different. Whole genome enrichment resulted in up to fourfold enrichment of the human endogenous DNA content for both dentin and dental calculus libraries, albeit with some loss in complexity. Recovering more on-target reads for the same sequencing effort generally improved the quality of downstream analyses, such as sex and ancestry estimation. For nonhuman DNA, comparison of phylum-level microbial community structure revealed few differences between precapture and postcapture libraries, indicating that off-target sequences in human genome-enriched calculus libraries may still be useful for oral microbiome reconstruction. Discussion: While ancient human dental calculus does contain endogenous human DNA sequences, their relative proportion is low when compared with other skeletal tissues. Whole genome enrichment can help increase the proportion of recovered human reads, but in this instance enrichment efficiency was relatively low when compared with other forms of capture. We conclude that further optimization is necessary before the method can be routinely applied to archaeological samples

Physical impacts of the CE 1600 Huaynaputina eruption on the local habitat: Geophysical insights

[ESP] El impacto climático global de la erupción del volcán Huaynaputina (IEV6) en 1600 está bien documentado pero las consecuencias regionales sobre las construcciones y los habitantes están poco conocidas. La localización de varios pueblos sepultados bajo los depósitos espesos del Huaynaputina no es claramente mencionada en las crónicas españolas. Investigaciones geofísicas realizadas durante el periodo 2015-2016 sobre diferentes sitios de ruinas a menos de 16 km del cráter constituyen la parte inicial de un proyecto denominado “Huayruro”, cuyo objetivo es entender mejor los impactos físicos y socio-económicos de esta erupción. Varios métodos e instrumentos geofísicos fueron utilizados: un drone y modelos numéricos de terreno de alta resolución, un geo-radar con imágenes 3D del subsuelo, el magnetismo, las imágenes infra-rojas y el electro-magnetismo. Esta investigación geofísica preliminar ha permitido identificar la futura estratégia y la mejor instrumentación para cartografiar el área del antiguo pueblo enterrado de Calicanto, localizando con precisión su extensión y los muros de las habitaciones. Este mapeo servirá para los futuros estudios tefro-estratigráficos y arqueológicos. El objetivo final del proyecto es diseminar los resultados del estudio multidisciplinar al público incluyendo la creación de un museo de sitio

Calibration of the Logarithmic-Periodic Dipole Antenna (LPDA) Radio Stations at the Pierre Auger Observatory using an Octocopter

An in-situ calibration of a logarithmic periodic dipole antenna with a frequency coverage of 30 MHz to 80 MHz is performed. Such antennas are part of a radio station system used for detection of cosmic ray induced air showers at the Engineering Radio Array of the Pierre Auger Observatory, the so-called Auger Engineering Radio Array (AERA). The directional and frequency characteristics of the broadband antenna are investigated using a remotely piloted aircraft (RPA) carrying a small transmitting antenna. The antenna sensitivity is described by the vector effective length relating the measured voltage with the electric-field components perpendicular to the incoming signal direction. The horizontal and meridional components are determined with an overall uncertainty of 7.4^{+0.9}_{-0.3} % and 10.3^{+2.8}_{-1.7} % respectively. The measurement is used to correct a simulated response of the frequency and directional response of the antenna. In addition, the influence of the ground conductivity and permittivity on the antenna response is simulated. Both have a negligible influence given the ground conditions measured at the detector site. The overall uncertainties of the vector effective length components result in an uncertainty of 8.8^{+2.1}_{-1.3} % in the square root of the energy fluence for incoming signal directions with zenith angles smaller than 60{\deg}.Comment: Published version. Updated online abstract only. Manuscript is unchanged with respect to v2. 39 pages, 15 figures, 2 table

Multi-resolution anisotropy studies of ultrahigh-energy cosmic rays detected at the Pierre Auger Observatory

We report a multi-resolution search for anisotropies in the arrival directions of cosmic rays detected at the Pierre Auger Observatory with local zenith angles up to $80^\circ$ and energies in excess of 4 EeV ($4 \times 10^{18}$ eV). This search is conducted by measuring the angular power spectrum and performing a needlet wavelet analysis in two independent energy ranges. Both analyses are complementary since the angular power spectrum achieves a better performance in identifying large-scale patterns while the needlet wavelet analysis, considering the parameters used in this work, presents a higher efficiency in detecting smaller-scale anisotropies, potentially providing directional information on any observed anisotropies. No deviation from isotropy is observed on any angular scale in the energy range between 4 and 8 EeV. Above 8 EeV, an indication for a dipole moment is captured; while no other deviation from isotropy is observed for moments beyond the dipole one. The corresponding $p$-values obtained after accounting for searches blindly performed at several angular scales, are $1.3 \times 10^{-5}$ in the case of the angular power spectrum, and $2.5 \times 10^{-3}$ in the case of the needlet analysis. While these results are consistent with previous reports making use of the same data set, they provide extensions of the previous works through the thorough scans of the angular scales.Comment: Published version. Added journal reference and DOI. Added Report Numbe