Long-term thermal sensitivity of Earth’s tropical forests

The sensitivity of tropical forest carbon to climate is a key uncertainty in predicting global climate change. Although short-term drying and warming are known to affect forests, it is unknown if such effects translate into long-term responses. Here, we analyze 590 permanent plots measured across the tropics to derive the equilibrium climate controls on forest carbon. Maximum temperature is the most important predictor of aboveground biomass (−9.1 megagrams of carbon per hectare per degree Celsius), primarily by reducing woody productivity, and has a greater impact per °C in the hottest forests (>32.2°C). Our results nevertheless reveal greater thermal resilience than observations of short-term variation imply. To realize the long-term climate adaptation potential of tropical forests requires both protecting them and stabilizing Earth’s climate

Height and body-mass index trajectories of school-aged children and adolescents from 1985 to 2019 in 200 countries and territories: a pooled analysis of 2181 population-based studies with 65 million participants

Summary Background Comparable global data on health and nutrition of school-aged children and adolescents are scarce. We aimed to estimate age trajectories and time trends in mean height and mean body-mass index (BMI), which measures weight gain beyond what is expected from height gain, for school-aged children and adolescents. Methods For this pooled analysis, we used a database of cardiometabolic risk factors collated by the Non-Communicable Disease Risk Factor Collaboration. We applied a Bayesian hierarchical model to estimate trends from 1985 to 2019 in mean height and mean BMI in 1-year age groups for ages 5–19 years. The model allowed for non-linear changes over time in mean height and mean BMI and for non-linear changes with age of children and adolescents, including periods of rapid growth during adolescence. Findings We pooled data from 2181 population-based studies, with measurements of height and weight in 65 million participants in 200 countries and territories. In 2019, we estimated a difference of 20 cm or higher in mean height of 19-year-old adolescents between countries with the tallest populations (the Netherlands, Montenegro, Estonia, and Bosnia and Herzegovina for boys; and the Netherlands, Montenegro, Denmark, and Iceland for girls) and those with the shortest populations (Timor-Leste, Laos, Solomon Islands, and Papua New Guinea for boys; and Guatemala, Bangladesh, Nepal, and Timor-Leste for girls). In the same year, the difference between the highest mean BMI (in Pacific island countries, Kuwait, Bahrain, The Bahamas, Chile, the USA, and New Zealand for both boys and girls and in South Africa for girls) and lowest mean BMI (in India, Bangladesh, Timor-Leste, Ethiopia, and Chad for boys and girls; and in Japan and Romania for girls) was approximately 9–10 kg/m2. In some countries, children aged 5 years started with healthier height or BMI than the global median and, in some cases, as healthy as the best performing countries, but they became progressively less healthy compared with their comparators as they grew older by not growing as tall (eg, boys in Austria and Barbados, and girls in Belgium and Puerto Rico) or gaining too much weight for their height (eg, girls and boys in Kuwait, Bahrain, Fiji, Jamaica, and Mexico; and girls in South Africa and New Zealand). In other countries, growing children overtook the height of their comparators (eg, Latvia, Czech Republic, Morocco, and Iran) or curbed their weight gain (eg, Italy, France, and Croatia) in late childhood and adolescence. When changes in both height and BMI were considered, girls in South Korea, Vietnam, Saudi Arabia, Turkey, and some central Asian countries (eg, Armenia and Azerbaijan), and boys in central and western Europe (eg, Portugal, Denmark, Poland, and Montenegro) had the healthiest changes in anthropometric status over the past 3·5 decades because, compared with children and adolescents in other countries, they had a much larger gain in height than they did in BMI. The unhealthiest changes—gaining too little height, too much weight for their height compared with children in other countries, or both—occurred in many countries in sub-Saharan Africa, New Zealand, and the USA for boys and girls; in Malaysia and some Pacific island nations for boys; and in Mexico for girls. Interpretation The height and BMI trajectories over age and time of school-aged children and adolescents are highly variable across countries, which indicates heterogeneous nutritional quality and lifelong health advantages and risks

Dementia in Latin America : paving the way towards a regional action plan

Regional challenges faced by Latin American and Caribbean countries (LACs) to fight dementia, such as heterogeneity, diversity, political instabilities, and socioeconomic disparities, can be addressed more effectively grounded in a collaborative setting based on the open exchange of knowledge. In this work, the Latin American and Caribbean Consortium on Dementia (LAC-CD) proposes an agenda for integration to deliver a Knowledge to Action Framework (KtAF). First, we summarize evidence-based strategies (epidemiology, genetics, biomarkers, clinical trials, nonpharmacological interventions, networking and translational research) and align them to current global strategies to translate regional knowledge into actions with transformative power. Then, by characterizing genetic isolates, admixture in populations, environmental factors, and barriers to effective interventions and mapping these to the above challenges, we provide the basic mosaics of knowledge that will pave the way towards a KtAF. We describe strategies supporting the knowledge creation stage that underpins the translational impact of KtAF

Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight NCD Risk Factor Collaboration (NCD-RisC)

From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions

PROPRIEDADES ESTATÍSTICAS DAS SÉRIES DE RETORNOS DAS PRINCIPAIS AÇÕES BRASILEIRAS

O artigo analisa seis séries de retornos, escolhidas entre as mais líquidas do mercado e de setores diferentes da economia. São estudadas a estacionariedade, a distribuição incondicional e a independência; de maneira geral as séries podem ser consideradas estacionárias, com distribuição não normal (leptocúrtica) e dependentes no tempo. A estacionariedade é analisada através do teste ADF, através dos coeficientes de modelos GARCH ajustados aos dados, pelos coeficientes de bicorrelação e com o uso de regressão localmente ponderada. A normalidade é rejeitada pelo teste de Jarque e Bera. A dependência (linear e não linear) é constatada pelas autocorrelações dos retornos e dos seus quadrados: tenta-se modelar a dependência com modelos ARMA, de amortecimento exponencial e GARCH mas os resíduos dos modelos, testados pelo teste BDS, mostram que nenhum deles representa bem o processo gerador dos dado

Métodos de medição de risco de mercado: um estudo comparativo Market risk measurement methods: a comparative study

A modelagem do risco de mercado é de grande importância para as instituições financeiras e outras firmas que participam do mercado financeiro. Os modelos e técnicas empregados no Brasil nem sempre são os mais adequados às nossas condições específicas. Este trabalho estuda dez modelos de estimação de risco (volatilidade) usando dados de ações brasileiras, e faz uma aplicação em determinação de VaR.<br>Market risk modeling is very important to any company that participates of the financial market. Brazilian companies use models and techniques that not necessarily are the most suited for the features of the Brazilian markets. This paper compares ten risk (volatility) models, using Brazilian stock data, and uses them to determine VaR

Ciencias sociales y relaciones internacionales : nuevas perspectivas desde América Latina

El valor de este libro radica en una doble condición: por una parte da cuenta de varias preocupaciones académicas persistentes en la disciplina; y por otra, contribuye a llenar el vacío de producción teórica en la región. El libro se organiza con una lógica que expone debates que van desde la reflexión epistemológica al análisis de la política exterior, y recorre campos relevantes para el desarrollo y comprensión de la disciplina. En América Latina, el desarrollo de los estudios internacionales es, en términos históricos, relativamente reciente. Durante buena parte del siglo XX, la mayoría de escuelas vinculadas a esta actividad estuvieron subsumidas en las Facultades de Jurisprudencia, y seguían una vieja tradición regional, anclada en perspectivas legales. Tres condiciones del entorno podrían explicar esta realidad

Ciencias Sociales y Relaciones Internacionales : nuevas perspectivas desde América Latina

Esta obra es un modesto intento para situar la disciplina de las Relaciones Internacionales dentro de las Ciencias Sociales, pero con una visión desde América Latina. El conjunto de trabajos, que se solicitaron expresamente a autoras y autores, se agrupa en tres secciones: i) Epistemología e Investigación; ii) Enfoques teóricos y metodológicos y iii) Estudio de casos.This work is a modest attempt to place the discipline of International Relations within the Social Sciences, but with a view from Latin America. The set of works, which is expressly requested from authors, is grouped into three sections: i) Epistemology and Research; ii) Theoretical and methodological approaches and iii) Case studies.Universidad Nacional, Costa RicaIDESPOCLACSOEscuela de Relaciones Internacionale