Los registros más antiguos del polen de <i>Nothofagus</i> (Fagaceae) de Patagonia (Argentina y Chile)

Se estudia la distribución y frecuencia de los granos de polen del organogenero Nothofagidites en sedimentos de distintas unidades litoestratigráficas de Patagonia. Se demuestra la presencia continua del género a partir del Maastrichtiano medio hasta el Eoceno. La frecuencia es muy baja en las formaciones cretácicas y danianas; aumenta en el Paleoceno superior y se hace significativa en el Eoceno. Se analizan los resultados en relación con las condiciones ambientales que han sido inferidas para este lapso en Patagonia. Finalmente se discuten los resultados estratigráficos, comparándolos con los registros conocidos para Australia y Nueva Zelandia.Trabajo publicado on line en 2016.Facultad de Ciencias Naturales y Muse

Distribución de la adiposidad corporal en el noroeste argentino : Interacción biología y medio geográfico

Catamarca y Jujuy situadas en el Noroeste Argentino, constituyen un enclave en donde la altitud geográfica es uno de los factores que determinan la variabilidad humana de la región. Así, los asentamientos se distribuyen en una gradación que va desde las zonas bajas hasta alturas que superan los 3500 msnm. Además, estas provincias que cuentan con un notable componente indígena, se encuentran entre las más desfavorecidas del país. Como parte de los proyectos de investigación CGL2005-03752 y PICTO2005-32451, se presenta un estudio de los niveles y distribución de la adiposidad corporal en escolares entre 6 y 18 años de edad, medidos en diferentes localidades situadas en tres niveles de altitud. La finalidad del trabajo es establecer el desarrollo la masa grasa durante el crecimiento en los habitantes de ecosistemas de altura. La muestra está constituida por 4141 escolares de ambos sexos, entre 6 y 18 años, clasificados de acuerdo a tres grupos de edad. Las medidas antropométricas directas fueron: peso, talla, perímetros de cintura, abdomen cadera y muslo y 6 pliegues subcutáneos. A partir de ellas se obtuvieron el índice de cintura/cadera, cintura/muslo, conicidad y relación de adiposidad entre los segmentos corporales superior y tronco. Se aplicaron los métodos del Programa Biológico Internacional (IBP) habituales en este tipo de estudios. Para comprobar el posible efecto de la altitud sobre los estimadores de la adiposidad se efectuó un ANOVA y pruebas post hoc de comparación múltiple de medias, agrupando las series tanto por niveles altitudinales como por grupos de edad y sexo. Resultados: Respecto a la cantidad de tejido adiposo medido a través de las medidas directas, se observa en el grupo localizado a más de 3000m, unos promedios significativamente más bajos respecto a los residentes a alturas menores. Además, en términos generales, las diferencias son mucho menores o inexistentes entre menos de 2000m y 2000-3000m. Los índices muestran distinto comportamiento. El índice de conicidad presenta escasas variaciones, resultando diferencias no significativas para la mayor parte de las edades y alturas. El índice de cintura/cadera aumenta ligeramente a partir de los 3000 m aunque a determinadas edades las diferencias son no significativas o se encuentran en el límite de la significación. En contraste, el índice de cintura/muslo muestra un aumento significativamente importante en los grupos que viven a más de 3000m. Por tanto la altitud, que está asociada a variaciones climáticas, aspectos socioeconómicos y de actividad física, condiciona el desarrollo de la adiposidad, no sólo en cuanto a cantidad sino, en alguna medida, también a sudistribución.Simposio: Crecimiento físico y variación altitudinaalAsociación de Antropología Biológica de la República Argentin

Waist circumference percentiles for Hispanic-American children and comparison with other international references

Introduction Waist circumference (WC) constitutes an indirect measurement of central obesity in children and adolescents. Objective To provide percentiles of WC for Hispanic-American children and adolescents, and compare them with other international references. Materials and methods The sample comprised 13 289 healthy children between 6 and 18 years coming from public schools of middle and low socioeconomic levels in different parts of Argentina, Cuba, Spain, Mexico, and Venezuela. The LMS method to calculate WC percentiles was applied. Sex and age differences were assessed using Student'sttest and ANOVA (SPSS v.21.0). Comparisons were established with references from the United States, Colombia, India, China, Australia, Kuwait, Germany, Tunisia, Greece, and Portugal. Results WC increases with age in both sexes. Boys show higher WC in P3, P50, and P97. Comparison of 50th and 90th percentiles among populations from diverse sociocultural and geographical contexts shows high variability, not all justified by the measurement method. Discussion and conclusions Specific WC percentiles for sex and age, and P90 cut-off points are provided; these values are potentially useful to assess central obesity in Hispanic-American adolescent children

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

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

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

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

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

Ten new insights in climate science 2020 – a horizon scan

Non-technical summary We summarize some of the past year's most important findings within climate change-related research. New research has improved our understanding of Earth's sensitivity to carbon dioxide, finds that permafrost thaw could release more carbon emissions than expected and that the uptake of carbon in tropical ecosystems is weakening. Adverse impacts on human society include increasing water shortages and impacts on mental health. Options for solutions emerge from rethinking economic models, rights-based litigation, strengthened governance systems and a new social contract. The disruption caused by COVID-19 could be seized as an opportunity for positive change, directing economic stimulus towards sustainable investments. Technical summary A synthesis is made of ten fields within climate science where there have been significant advances since mid-2019, through an expert elicitation process with broad disciplinary scope. Findings include: (1) a better understanding of equilibrium climate sensitivity; (2) abrupt thaw as an accelerator of carbon release from permafrost; (3) changes to global and regional land carbon sinks; (4) impacts of climate change on water crises, including equity perspectives; (5) adverse effects on mental health from climate change; (6) immediate effects on climate of the COVID-19 pandemic and requirements for recovery packages to deliver on the Paris Agreement; (7) suggested long-term changes to governance and a social contract to address climate change, learning from the current pandemic, (8) updated positive cost–benefit ratio and new perspectives on the potential for green growth in the short- and long-term perspective; (9) urban electrification as a strategy to move towards low-carbon energy systems and (10) rights-based litigation as an increasingly important method to address climate change, with recent clarifications on the legal standing and representation of future generations. Social media summary Stronger permafrost thaw, COVID-19 effects and growing mental health impacts among highlights of latest climate science

Fossil Evidence Regarding the Evolution of Nothofagus Blume

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