Trajectories of alcohol consumption during life and the risk of developing breast cancer

Background: Whether there are lifetime points of greater sensitivity to the deleterious effects of alcohol intake on the breasts remains inconclusive. Objective: To compare the influence of distinctive trajectories of alcohol consumption throughout a woman’s life on development of breast cancer (BC). Methods: 1278 confirmed invasive BC cases and matched (by age and residence) controls from the Epi-GEICAM study (Spain) were used. The novel group-based trajectory modelling was used to identify different alcohol consumption trajectories throughout women’s lifetime. Results: Four alcohol trajectories were identified. The first comprised women (45%) with low alcohol consumption (<5 g/day) throughout their life. The second included those (33%) who gradually moved from a low alcohol consumption in adolescence to a moderate in adulthood (5 to <15 g/day), never having a high consumption; and oppositely, women in the third trajectory (16%) moved from moderate consumption in adolescence, to a lower consumption in adulthood. Women in the fourth (6%) moved from a moderate alcohol consumption in adolescence to the highest consumption in adulthood (=15 g/day), never having a low alcohol consumption. Comparing with the first trajectory, the fourth doubled BC risk (OR 2.19; 95% CI 1.27, 3.77), followed by the third (OR 1.44; 0.96, 2.16) and ultimately by the second trajectory (OR 1.17; 0.86, 1.58). The magnitude of BC risk was greater in postmenopausal women, especially in those with underweight or normal weight. When alcohol consumption was independently examined at each life stage, =15 g/day of alcohol consumption in adolescence was strongly associated with BC risk followed by consumption in adulthood. Conclusions: The greater the alcohol consumption accumulated throughout life, the greater the risk of BC, especially in postmenopausal women. Alcohol consumption during adolescence may particularly influence BC risk. © 2021, The Author(s)

The role of fragmentation and landscape changes in the ecological release of common nest predators in the Neotropics

Loss of large mammalian carnivores may allow smaller mesopredators to become abundant and threaten other community members. There is considerable debate about mesopredator release and the role that other potential factors such as landscape variables and human alterations to land cover lead to increased mesopredator abundance. We used camera traps to detect four mesopredators (tayra, Eira barbara; white-nosed coati, Nasua narica; northern raccoon, Procyon lotor; and common opossum, Didelphis opossum) in a biological corridor in Costa Rica to estimate habitat covariates that influenced the species’ detection and occurrence. We selected these mesopredators because as semi-arboreal species they might be common nest predators, posing a serious threat to resident and migratory songbirds. Pineapple production had a pronounced positive effect on the detectability of tayras, while forest cover had a negative effect on the detection of coatis. This suggests that abundance might be elevated due to the availability of agricultural food resources and foraging activities are concentrated in forest fragments and pineapple edge habitats. Raccoon and opossum models exhibited little influence on detection from habitat covariates. Occurrence models did not suggest any significant factors influencing site use by nest predators, revealing that all four species are habitat generalists adapted to co-existing in human altered landscapes. Furthermore, fragmentation and land cover changes may predispose nesting birds, herpetofauna, and small mammals to heightened predation risk by mesopredators in the Neotropics

Transporte de humedad y variaciones estacionales en la composición isotópica estable de la lluvia en el páramo centroamericano y andino durante las condiciones de El Niño (2015-2016)

Los sistemas de pastizales tropicales de gran altitud, llamados Páramo, brindan servicios ecosistémicos esenciales como el almacenamiento y el suministro de agua para las áreas circundantes y de tierras bajas. Los sistemas de páramo están amenazados por los cambios climáticos y de uso del suelo. Los procesos de generación de lluvia y las vías de transporte de humedad que influyen en la precipitación en el Páramo no se conocen bien, pero se necesitan para estimar el impacto de estos cambios, particularmente durante las condiciones de El Niño, que afectan en gran medida las condiciones hidrometeorológicas en las regiones tropicales. Para llenar este vacío de conocimiento, presentamos un análisis de isótopos estables de las muestras de lluvia recolectadas diariamente o semanalmente entre enero de 2015 y mayo de 2016 durante el evento de El Niño más fuerte registrado en la historia (2014-2016) en dos regiones de Páramo de América Central (Chirripó, Costa Rica) y el norte de los Andes (Cajas, sur de Ecuador). Se utilizaron composiciones isotópicas para identificar cómo los procesos de generación de lluvia (convectiva y orográfica) cambian estacionalmente en cada sitio de estudio. Se usó el análisis de trayectoria de masa de aire híbrido de modelo de trayectoria integrada lagrangiana de partícula única (HYSPLIT) para identificar rutas preferenciales de transporte de humedad a cada sitio de Páramo. Nuestros resultados muestran la fuerte influencia de los vientos alisios del noreste para transportar la humedad del Mar Caribe a Chirripó y el jet sudamericano de bajo nivel para transportar la humedad del bosque amazónico a Cajas. Estas contribuciones de humedad también se relacionaron con la formación de lluvia convectiva asociada con el paso de la Zona de Convergencia Intertropical sobre Costa Rica y Ecuador durante las estaciones más húmedas y con la precipitación orográfica durante las temporadas de transición y más secas. Nuestros hallazgos brindan información básica esencial para futuras aplicaciones de investigación de isótopos estables al agua como trazadores de procesos de generación de lluvia y transporte en el Páramo y otros ecosistemas montanos en los trópicos.High‐elevation tropical grassland systems, called Páramo, provide essential ecosystem services such as water storage and supply for surrounding and lowland areas. Páramo systems are threatened by climate and land use changes. Rainfall generation processes and moisture transport pathways influencing precipitation in the Páramo are poorly understood but needed to estimate the impact of these changes, particularly during El Niño conditions which largely affect hydrometeorological conditions in tropical regions. To fill this knowledge gap, we present a stable isotope analysis of rainfall samples collected on a daily to weekly basis between January 2015 and May 2016 during the strongest El Niño event recorded in history (2014‐2016) in two Páramo regions of Central America (Chirripó, Costa Rica) and the northern Andes (Cajas, south Ecuador). Isotopic compositions were used to identify how rainfall 

Size-selective optical printing of silicon nanoparticles through their dipolar magnetic resonance

Silicon nanoparticles possess unique size-dependent optical properties due to their strong electric and magnetic resonances in the visible range. However, their widespread application has been limited, in comparison with other (e.g., metallic) nanoparticles, because their preparation on monodisperse colloids remains challenging. Exploiting the unique properties of Si nanoparticles in nano- A nd microdevices calls for methods able to sort and organize them from a colloidal suspension onto specific positions of solid substrates with nanometric precision. We demonstrate that surfactant-free silicon nanoparticles of a predefined and narrow (σ < 10 nm) size range can be selectively immobilized on a substrate by optical printing from a polydisperse colloidal suspension. The size selectivity is based on differential optical forces that can be applied on nanoparticles of different sizes by tuning the light wavelength to the size-dependent magnetic dipolar resonance of the nanoparticles

Key drivers controlling stable isotope variations in daily precipitation of Costa Rica: Caribbean Sea versus Eastern Pacific Ocean moisture

2013-2017: International Atomic Energy Agency, Vienna, Austria, Project CRP 17947: Stable isotopes in precipitation and paleoclimatic archives in tropical areas to improve regional hydrological and climatic impact modelsCosta Rica is located on the Central American Isthmus, which receives moisture inputs directly from the Caribbean Sea and the Eastern Pacific Ocean. This location includes unique mountainous and lowland microclimates, but only limited knowledge exists about the impact of relief and regional atmospheric circulation patterns on precipitation origin, transport, and isotopic composition. Therefore, the main scope of this project is to identify the key drivers controlling stable isotope variations in daily-scale precipitation of Costa Rica. The monitoring sites comprise three strategic locations across Costa Rica: Heredia (Central Valley), Turrialba (Caribbean slope), and Caño Seco (South Pacific slope). Sporadic dry season rain is mostly related to isolated enriched events ranging from −5.8‰ to −0.9‰ δ18O. By mid-May, the Intertropical Convergence Zone reaches Costa Rica resulting in a notable depletion in isotope ratios (up to −18.5‰ δ18O). HYSPLIT air mass back trajectories indicate the strong influence on the origin and transport of precipitation of three main moisture transport mechanisms, the Caribbean Low Level Jet, the Colombian Low Level Jet, and localized convection events. Multiple linear regression models constructed based on Random Forests of surface meteorological information and atmospheric sounding profiles suggest that lifted condensation level and surface relative humidity are the main factors controlling isotopic variations. These findings diverge from the recognized ‘amount effect’ in monthly composite samples across the tropics. Understanding of stable isotope dynamics in tropical precipitation can be used to a) enhance groundwater modeling efforts in ungauged basins where scarcity of long-term monitoring data drastically limit current and future water resources management, b) improve the re-construction of paleoclimatic records in the Central American land bridge, c) calibrate and validate regional circulation models.Costa Rica está ubicada en el Istmo Centroamericano, que recibe aportes de humedad directamente del Mar Caribe y del Océano Pacífico Oriental. Esta ubicación incluye microclimas montañosos y de tierras bajas únicas, pero solo existe un conocimiento limitado sobre el impacto del relieve y los patrones de circulación atmosférica regional sobre el origen, el transporte y la composición isotópica de las precipitaciones. Por lo tanto, el alcance principal de este proyecto es identificar los impulsores clave que controlan las variaciones de isótopos estables en la precipitación a escala diaria de Costa Rica. Los sitios de monitoreo comprenden tres ubicaciones estratégicas en Costa Rica: Heredia (Valle Central), Turrialba (vertiente del Caribe) y Caño Seco (vertiente del Pacífico Sur). La lluvia esporádica de la estación seca se relaciona principalmente con eventos enriquecidos aislados que van desde −5,8 ‰ a −0,9 ‰ δ18O. A mediados de mayo, la Zona de Convergencia Intertropical llega a Costa Rica, lo que resulta en un notable agotamiento de las proporciones de isótopos (hasta −18,5 ‰ δ18O). Las trayectorias de retroceso de la masa de aire de HYSPLIT indican la fuerte influencia en el origen y transporte de la precipitación de tres mecanismos principales de transporte de humedad, el chorro de bajo nivel del Caribe, el chorro de bajo nivel de Colombia y los eventos de convección localizados. Múltiples modelos de regresión lineal construidos a partir de bosques aleatorios de información meteorológica de superficie y perfiles de sondeo atmosférico sugieren que el nivel de condensación elevado y la humedad relativa de la superficie son los principales factores que controlan las variaciones isotópicas. Estos hallazgos difieren del "efecto de cantidad" reconocido en muestras compuestas mensuales en los trópicos. La comprensión de la dinámica de isótopos estables en la precipitación tropical se puede utilizar para a) mejorar los esfuerzos de modelado de aguas subterráneas en cuencas no calibradas donde la escasez de datos de monitoreo a largo plazo limita drásticamente la gestión actual y futura de los recursos hídricos, Puente terrestre centroamericano, c) calibrar y validar modelos de circulación regional.Escuela de Químic