Recent research findings have highlighted the importance of early life conditions as risk factors for adult diseases and therefore determinants of subsequent survival. Given that individuals born during different seasons in seasonal environments experience different early-developmental conditions, an analysis of the effects of the season of birth on survival is considered an effective approach in clarifying the influence of early life conditions on survival in later life. In the present study, we analyzed the long-term effects of early developmental conditions in a historical population in which both nutritional levels and the burden of infectious diseases showed a seasonal variation. Using a semi-computerized linkage process, we were able to match birth and death data for 4,646 individuals born between 1634 and 1870 in the village of Es Mercadal (Minorca Island, Spain). To determine ecological differences associated with the season of birth, we first evaluated the association between season of birth and early life survival. This analysis helped us to determine seasonal variations in early life conditions such as infectious burden and nutritional levels. The season of birth had a significant effect on long-term survival in the birth cohort 1800-1870: summer births had a lower risk of death after age 15. We explain these results in terms of lower susceptibility to degenerative diseases in adult years due to superior in utero nutrition for summer births. These findings support the fetal origin hypothesis which states that the early life environment plays a key role in shaping the subsequent phenotype and risk of adult disease.

Early initiation of pregabalin treatment after diagnosis in patients with refractory chronic PNP may result in substantial cost savings from a societal perspective in daily practice in Spain.

Autoregressive integrated moving average (ARIMA) models provide a powerful tool for detecting seasonal patterns in mortality statistics. The strength of ARIMA models lies in their ability to reveal complex structures of temporal interdependence in time series. Moreover, changes in model parameters provide an empirical basis for detecting secular trends and death seasonality patterns. This approach is illustrated by our analysis of changes in the mortality patterns of the population of the town of Es Mercadal on the island of Minorca between 1634 and 1997. These data reveal a transition from an early mortality pattern requiring a complex ARIMA model that accounts for a strong seasonal death pattern and periodic epidemic-related mortality crises to a much simpler 20th-century pattern that can be described by a simple single-parameter ARIMA model. These same data were also analyzed using standard seasonality tests. The results show that the reduction in the number of parameters required to fit the Es Mercadal mortality data coincides with the epidemiological transition in which the predominant causes of morbidly and mortality shift from infectious to degenerative causes.

RESUMENEl presente estudio analiza la información obtenida a través de 182 encuestas de fecundidad a mujeres en edad posreproductora de la Tierra del Fuego chilena. La muestra es representativa de la población femenina fueguina desde casi el inicio de la colonización. Se describen los distintos eventos e intervalos que definen la historia reproductora de estas mujeres, además de sus valores de fecundidad y de fecundidad marital. Su vida reproductiva, toda ella transcurrida en la isla, se caracteriza por un largo intervalo fértil, un corto intervalo fecundo y una reducida fecundidad, y se constata cómo la mayor eficiencia de uso de sus años reproductores se traduce en un tamaño de la progenie mayor. Finalmente, se realizan dos aproximaciones distintas al estudio de los determinantes de la fecundidad de las mujeres de la población: por un lado, el análisis mediante el modelo agregativo de la fecundidad descrito por Bongaarts y Potter y, por otro, la aplicación del path analysis. Los patrones de nupcialidad, el ritmo de concepción y las prácticas de anticoncepción son propuestos como los principales determinantes de la fecundidad en las mujeres chilenas de Tierra del Fuego.PALABRAS CLAVES: Fecundidad, determinantes próximos, path análisis. WOMEN FERTILITY AND REPRODUCTIVE YEARS IN CHILEAN TIERRA DEL FUEGO ABSTRACTThe present study analyzes 182 interviews to postmenopausal women of the Chilean part of Tierra del Fuego. These women can be considered a representative sample of the population of the region from the beginning of the recent settlement. Events and intervals that explain reproductive lifes of these women are described, and fertility and marital fertility rates are calculated. The reproductive history of these women is characterized by a long fertile span, a short childbearing period, and low fertility. It was observed that the higher the efficiency of use of their reproductive years, the larger the number of surviving children. Finally, two different pathways were chosen to study fertility determinants of these women: Bongaarts' fertility aggregative model and path analysis. Marriage patterns, the rhythm of conception and practices of contraception are proposed as the main determinants of fertility in Tierra del Fuego.