Caracterización geoquímica y tecnológica de un depósito de cuarzo de alta pureza, localizado en cercanías de la estación Pablo Acosta, partido de Azul, Provincia de Buenos Aires (Argentina)

El cuarzo (SiO2) es un mineral ampliamente utilizado en varias industrias. Sus aplicaciones dependen de sus propiedades físicas y químicas y del contenido de impurezas que poseen los cristales. El cuarzo más requerido es aquel de alta pureza (CAP), sin embargo, los yacimientos de este tipo son mundialmente escasos. En el partido de Azul, se determinó la presencia de un cuerpo rocoso de dimensiones considerables compuesto casi totalmente por cuarzo. El estudio petrográfico permitió determinar cristales de cuarzo de variable dimensión (70-600 μm) y de filosilicatos (escasos). Además, se reconocieron microestructuras de deformación dúctil y frágil. Los análisis geoquímicos realizados en dos muestras, sin y con preselección manual, indicaron contenidos de SiO₂ de 95 y 97 % respectivamente, y contenidos menores de Al₂O₃ (< 1,50 %), Fe₂O₃ (< 0,55 %) y K₂O (< 0,50 %). Por otro lado, se observaron escasas inclusiones fluidas. De acuerdo con los resultados obtenidos el cuerpo cuarzoso estudiado cumple con las condiciones establecidas para ser clasificado como CAP. Considerando los requerimientos de las distintas industrias, este mineral podría ser utilizado, sin ningún tipo de tratamiento, en la industria de las ferroaleaciones, y en el caso de aplicar algún método de purificación, en la industria del vidrio.Quartz (SiO2) is a known mineral that has important applications in various industries. ese applications mainly dependonits physical and chemical properties and on the impurity contents it contains. High-purity quartz (HPQ) is the most required but this deposit type is globally scarce. e presence of a rock body with considerable dimension and almost entirely composed of quartz was determined in the city of Azul. Petrographic studies revealed quartz crystals (70-600 μm) and a few phyllosilicate crystals. In addition, ductile and fragile deformation microstructures were recognized. Geochemical analyzes carried out on two samples, without and with manual preselection, indicated SiO₂ contents of 95-97 wt. %, and low contents of Al₂O₃ (<1.50 wt.%), Fe₂O₃ (<0.55 wt.%) and K₂O (<0.50 wt.%). On the other hand, a few fluid inclusions were observed. According to the obtained results, the studied quartz body reachesout to the conditions established to be classified as HPQ. Considering industry requirements, this mineral could be used in the ferroalloy industry, without treatments, and in the glass industry for color less packaging or insulation fiber–manufacturing if some purification methods are applied.Instituto de Recursos Minerale

Geología de un cuerpo cuarzoso en el área de la Estación Pablo Acosta, partido de Azul, basamento del Sistema de Tandilia

Among the several outcrops of the mainly Palaeoproterozoic igneous-metamorphic basement of the Tandilia System exposed near the Estación Pablo Acosta, a quartz body, associated to a NE-SO shear zone, was identified. Field work, petrologic and geochemical studies revealed that it was formed from a siliceous fluid generated by metamorphic differentiation during the Transamazonian orogeny. On the other hand, the high degree of quartz purity together with the estimated outcropping volume points out a potential importance for industrial commercialization of the mineralization. In addition, this research provides valuable information to the geological-genetic model for the Tandilia System of the Buenos Aires Province

Tropical field stations yield high conservation return on investment

Conservation funding is currently limited; cost‐effective conservation solutions are essential. We suggest that the thousands of field stations worldwide can play key roles at the frontline of biodiversity conservation and have high intrinsic value. We assessed field stations’ conservation return on investment and explored the impact of COVID‐19. We surveyed leaders of field stations across tropical regions that host primate research; 157 field stations in 56 countries responded. Respondents reported improved habitat quality and reduced hunting rates at over 80% of field stations and lower operational costs per km2 than protected areas, yet half of those surveyed have less funding now than in 2019. Spatial analyses support field station presence as reducing deforestation. These “earth observatories” provide a high return on investment; we advocate for increased support of field station programs and for governments to support their vital conservation efforts by investing accordingly

Forest Biomass Density across Large Climate Gradients in Northern South America is related to Water Availability but not with Temperature

Understanding and predicting the likely response of ecosystems to climate change are crucial challenges for ecology and for conservation biology. Nowhere is this challenge greater than in the tropics as these forests store more than half the total atmospheric carbon stock in their biomass. Biomass is determined by the balance between biomass inputs (i.e., growth) and outputs (mortality). We can expect therefore that conditions that favor high growth rates, such as abundant water supply, warmth, and nutrient-rich soils will tend to correlate with high biomass stocks. Our main objective is to describe the patterns of above ground biomass (AGB) stocks across major tropical forests across climatic gradients in Northwestern South America. We gathered data from 200 plots across the region, at elevations ranging between 0 to 3400 m. We estimated AGB based on allometric equations and values for stem density, basal area, and wood density weighted by basal area at the plot-level. We used two groups of climatic variables, namely mean annual temperature and actual evapotranspiration as surrogates of environmental energy, and annual precipitation, precipitation seasonality, and water availability as surrogates of water availability. We found that AGB is more closely related to water availability variables than to energy variables. In northwest South America, water availability influences carbon stocks principally by determining stand structure, i.e. basal area. When water deficits increase in tropical forests we can expect negative impact on biomass and hence carbon storage

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

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

Anales del III Congreso Internacional de Vivienda y Ciudad "Debate en torno a la nueva agenda urbana"

Acta de congresoEl III Congreso Internacional de Vivienda y Ciudad “Debates en torno a la NUEVa Agenda Urbana”, ha sido una apuesta de alto compromiso por acercar los debates centrales y urgentes que tensionan el pleno ejercicio del derecho a la ciudad. Para ello las instituciones organizadoras (INVIHAB –Instituto de Investigación de Vivienda y Hábitat y MGyDH-Maestría en Gestión y Desarrollo Habitacional-1), hemos convidado un espacio que se concretó con potencia en un debate transdisciplinario. Convocó a intelectuales de prestigio internacional, investigadores, académicos y gestores estatales, y en una metodología de innovación articuló las voces académicas con las de las organizaciones sociales y/o barriales en el Foro de las Organizaciones Sociales que tuvo su espacio propio para dar voz a quienes están trabajando en los desafíos para garantizar los derechos a la vivienda y los bienes urbanos en nuestras ciudades del Siglo XXI

Enfermedad periodontal en pacientes con discapacidad en custodia versus pacientes con discapacidad independientes

Objetivo: Identificar el estado de salud periodontal en pacientes con discapacidad en custodia versus pacientes independientes en su higiene oral. Material y métodos: Se examinaron pacientes con discapacidad, ambos sexos, 3 a 19 años que acuden al Servicio de Odontopediatría del Centro de Rehabilitación Infantil Teletón (CRIT) Tamaulipas mediante revisión de cavidad oral y aplicación del Índice de Higiene Oral Simplificado (IHOS), Índice Periodontal Comunitario de la Necesidad de Tratamiento (IPCNT) y entrevista con su cuidador primario. Se agruparon en dos categorías: Independientes y de Custodia. Resultados: En el total de la muestra la Media y Desviación estándar (D.E.) de IPCNT fue de 0.89±0.54, así como el IHOS de 1.88±0.77. El IPCNT en pacientes con discapacidad de Custodia fue 0.91±0.57 e Independientes de 0.86±0.49 (p=0.70), IHOS en pacientes de Custodia 1.89±0.78 e Independientes 1.87±.0.74 (p=.93). IPCNT en géneros masculino 1.03±0.54 y femenino 0.75±0.51 (p=.009). IHOS en pacientes que habitan área rural 2.41±1.25 y área urbana 1.83±0.68 (p=.02). Relación entre la edad y la necesidad de tratamiento periodontal (p=0.001). Frecuencia del cepillado del grupo Independientes 2.03±0.56 y de Custodia 2.00±0.75 (p=.84). Conclusiones: No existe diferencia en el estado de salud periodontal y el grado de higiene oral entre pacientes con discapacidad Independientes y de Custodia. La mayoría de los pacientes Independientes y de Custodia tienen una necesidad de tratamiento de Instrucción de Higiene Oral (TN1) y tienen Higiene Oral Regular

Phosphatidylinositol 3-kinase interacts with the glucocorticoid receptor upon TLR2 activation

Airway inflammation is a common condition where glucocorticoids (GC) are a well-established therapy. It has been demonstrated that GC stimulate components of innate immunity. Specifically, GC up-regulate TLR2 expression and activation upon inflammatory stimuli; however, little is known about the signalling involved in this process. To determine the mechanism by which dexamethasone modulates TLR2-induced cytokine production this signalling pathway was monitored in a lung epithelial cell line exposed to the TLR2 synthetic agonist, Pam 3-Cys-Ser-Lys 4. These experiments demonstrate that phosphatidylinositol 3-kinase (PI3K) is critical for the TLR2 downstream effects of GC. Cells expressing a PI3K mutant (p85-dominant negative, DN; p85 Δ478-511) and exposed to Pam 3-Cys-Ser-Lys 4 in the presence or absence of dexamethasone, showed enhanced tumour necrosis factor (TNF)α expression while AP-1 and NF-κB transcriptional activity were repressed. We provide experimental evidence that PI3K physi

Using an on-site laboratory for fecal steroid analysis in wild white-faced capuchins.

Hormone laboratories located "on-site" where field studies are being conducted have a number of advantages. On-site laboratories allow hormone analyses to proceed in near-real-time, minimize logistics of sample permits/shipping, contribute to in-country capacity-building, and (our focus here) facilitate cross-site collaboration through shared methods and a shared laboratory. Here we provide proof-of-concept that an on-site hormone laboratory (the Taboga Field Laboratory, located in the Taboga Forest Reserve, Costa Rica) can successfully run endocrine analyses in a remote location. Using fecal samples from wild white-faced capuchins (Cebus imitator) from three Costa Rican forests, we validate the extraction and analysis of four steroid hormones (glucocorticoids, testosterone, estradiol, progesterone) across six assays (DetectX® and ISWE, all from Arbor Assays). Additionally, as the first collaboration across three long-term, wild capuchin field sites (Lomas Barbudal, Santa Rosa, Taboga) involving local Costa Rican collaborators, this laboratory can serve as a future hub for collaborative exchange

Biodiversity 2016. Status and Trends of Colombian Continental Biodiversity

This third volume of the annual report on biodiversity in Colombia continues the editorial line that begun in 2014. Using novel analytical and graphic proposals, these reports have the goal of communicating the contents to a broad public, making it available for discussion without sacrificing the quality of information. The challenge of communication continues to be a major part of the institutional project, and the new languages with which we are learning to communicate with society and other institutions are an experiment that we expect to be increasingly gratifying. The report for 2017 is already under construction and it counts on new digital technologies so the power of a colombian vital connection may be entirely expressed. The included content evidences that we are still far away from having a systematic follow-up about most of the topics related to the management of biodiversity and ecosystem services, which is the only way to evaluate the effectiveness of policies and investments made by society. In fact, a limitation that is recognized is that of identifying positive or negative changes that affect different levels of organization of life on this planet; therefore, our global navigation route of the Aichi targets is still to be verified. An additional purpose of this process includes the invitation of all Colombians to contribute in constructing and maintaining basic monitoring indicators for management since it is impossible to identify long-term trends of flora and fauna in the country without the support of institutions, researchers, and citizens. This challenge is immense in a megadiverse country such as Colombia. For this reason, the report will continue to open its pages to experts, and even indigenous peoples or local communities, for them to present their perspectives about environmental change and its effects on biodiversity in a systematic and documented manner. This has the objective of stimulating the commitment of everyone in the management of biodiversity and ecosystem services. The only way of overcoming the risk of extinction is through the active process of social learning in which all sectors assume a part of the complex responsibility in protecting the forms of life of the country, a roughly counted tenth of all creatures on Earth. I thank all the people that contributed in this Report, those who have supported us in the phases of production, and all readers and users, who are the ultimate judges of its utility.Bogotá, D. C