Mortality forecasting in Colombia from abridged life tables by sex.

BACKGROUND: An adequate forecasting model of mortality that allows an analysis of different population changes is a topic of interest for countries in demographic transition. Phenomena such as the reduction of mortality, ageing, and the increase in life expectancy are extremely useful in the planning of public policies that seek to promote the economic and social development of countries. To our knowledge, this paper is one of the first to evaluate the performance of mortality forecasting models applied to abridged life tables. OBJECTIVE: Select a mortality model that best describes and forecasts the characteristics of mortality in Colombia when only abridged life tables are available. DATA AND METHOD: We used Colombian abridged life tables for the period 1973-2005 with data from the Latin American Human Mortality Database. Different mortality models to deal with modeling and forecasting probability of death are presented in this study. For the comparison of mortality models, two criteria were analyzed: graphical residuals analysis and the hold-out method to evaluate the predictive performance of the models, applying different goodness of fit measures. RESULTS: Only three models did not have convergence problems: Lee-Carter (LC), Lee-Carter with two terms (LC2), and Age-Period-Cohort (APC) models. All models fit better for women, the improvement of LC2 on LC is mostly for central ages for men, and the APC model's fit is worse than the other two. The analysis of the standardized deviance residuals allows us to deduce that the models that reasonably fit the Colombian mortality data are LC and LC2. The major residuals correspond to children's ages and later ages for both sexes. CONCLUSION: The LC and LC2 models present better goodness of fit, identifying the principal characteristics of mortality for Colombia.Mortality forecasting from abridged life tables by sex has clear added value for studying differences between developing countries and convergence/divergence of demographic changes.

Use of gps and gis for monitoring of cattle's grazing on a silvipasture of tolima (colombia)

Cattle behavior and grazing distribution is probably related to the available food, although it could also be influenced by the canopy shade, ambient temperature and access to water. The objective of this study was to evaluate the interaction among tree cover (TC) and cattle positions (CP) when searching for food and comfort areas, under warm and hot weather, in a silvopasture system. Analyses were conducted on Pajonales farm, located in the municipality of Ambalema (lat. 4° 45' 25.9" N; 74° 52' 20.8" W) in Colombia, from December 2009 to January 2010. The farm has an average elevation of 300 masl. Mean precipitation is 1270 mm.year-1, and temperature 28°C. The pasture used for this study had an area of approximately 54 ha, with topography from flat to gently sloping. TC was determined from digital orthophotos QuickBird using ArcGIS® 9.1. The paddock was segmented into a 0.25 ha grid cell lattice and all sapling canopies within grid cells and animal movement were mapped. Six cows (3 Brahman and 3 F1, Brahman x Holstein) equipped with GPS-collars (Garmin eTrex-Vista) configured to record and store position, were tracked during 60 days at 5-min intervals. Average values indicate that cows, generally, traveled greater distances in warm period (7.4 km) and 6.1 km in the hot period. Cows prefer areas with low TC (< 20%) and intermediate TC (20-40%); these areas had more biomass of fodder dry matter. The study is an important contribution to understanding the dynamics of animals in search for food under grazing conditions.

El comportamiento del ganado y la distribución del pastoreo puede estar relacionado a los alimentos disponibles, aunque también podría influir el dosel forestal, la temperatura ambiente y el acceso al agua. El objetivo de este estudio fue evaluar la interacción entre la cobertura arbórea (CA) y la ubicación del ganado (UG) cuando buscan una zona para comer y estar cómodos, en climas templados y cálidos, en un sistema de silvopastoril. El análisis se realizó en la finca Pajonales, ubicada en el municipio de Ambalema (lat 4 ° 45 '25 .9 "N; 74 ° 52 '20.8" W) en Colombia, desde diciembre de 2009 hasta enero de 2010. La finca tiene una elevación promedio de 300 msnm. La precipitación es 1270 mm. año-1, y la temperatura es de 28 ° C. El pasto utilizado para este estudio tenía un área de aproximadamente 54 ha, con una topografía plana, hasta una pendiente suave. La CA se determinó a partir de las ortofotos digitales QuickBird utilizando ArcGIS® 9.1. El potrero se dividió en un entramado en cuadricula de 0.25 ha y se cartografió el dosel de todos los árboles jóvenes dentro del entramado y el movimiento del animal. Se rastrearon seis vacas (3 Brahman y 3 F1, Brahman x Holstein) equipadas con collares de localización satelital (Garmin eTrex-Vista) configurados para registrar y almacenar la posición, durante 60 días a intervalos de 5 minutos. Los valores promedio indican que las vacas, en general, viajaron distancias mayores en el periodo de clima templado (7,4 km) y 6,1 km en el período cálido. Las vacas prefieren las áreas con poca CA (< 20%) e intermedio CA (20-40%); Estas áreas tenían más biomasa de follaje. El estudio es una contribución importante para comprender la dinámica de los animales en la búsqueda de alimentos en condiciones de pastoreo.

O comportamento do gado e a distribuição do apascentamento podem estar relacionados aos alimentos disponíveis, embora também podem ser afetadas pelo dossel florestal, a temperatura ambiente e o acesso à água. O objetivo deste estudo foi avaliar a interação entre a cobertura de árvores (CA) e localização de gado (LG) na busca de uma área para comer e permanecer confortável em climas temperados e quentes, num sistema de silvipastagen. A análise foi realizada na fazenda Pajonale, localizada no município de Ambalema (lat 4° 45' 25,9" N; 74° 52' 20,8" O) na Colômbia, de dezembro de 2009 a janeiro de 2010. A fazenda possui uma elevação média de 300 metros acima do nível do mar. A precipitação média anual é de 1270 mm, ano-1, e a temperatura é de 28°C. O pasto usado para este estudo tinha uma área de aproximadamente 54 ha, com uma topografia plana a um declive suave. A CA foi determinada a partir das ortofotos digitais QuickBird usando o ArcGIS® 9.1. O potreiro foi dividido em uma estrutura de reticulado de 0,25 ha e o dossel de todas as árvores jovens dentro da estrutura e movimento do animal foi mapeado. Foram rastreadas seis vacas (3 Brahman e 3 F1, Brahman x Holstein) equipadas com colares de localização por satélite (Garmin eTrex-Vista) configurados para registrar e armazenar a posição durante 60 dias a intervalos de 5 minutos. Os valores médios indicam que as vacas, em geral, percorreram maiores distâncias no período de clima temperado (7,4 km) e 6,1 km no período quente. As vacas preferem áreas com pouco CA (< 20%) e CA intermédio (20-40%). Essas áreas tinham mais biomassa de folhagem. O estudo é uma importante contribuição para o entendimento da dinâmica dos animais na busca por alimentos em condições de pastejo.

Characterization of the immunoreactivity of anti-interferon alpha antibodies in myasthenia gravis patients. Epitope mapping.

Cytokines, such as interferons (IFN), underlie many immunological functions and are increasingly implicated in disease-related symptoms and pathology. In order to study the potential roles of IFN alpha and its antagonists in autoimmune phenomena, the sera from 89 patients (aged 15-95 years, 65 females) diagnosed as having myasthenia gravis (MG) (2 months to 34 years duration) were tested for the presence of natural anti-IFN alpha-2b auto-antibodies. Sera were screened for anti-IFN alpha-2b by a sandwich-type enzyme immunoassay system. Ten (11.2%) and 6 (6.7%) sera were identified that contained positive-competing and non-competing anti-IFN alpha-2b auto-antibodies, respectively. The MG sera were further analyzed by immunobloting against reduced IFN alpha-2b and for neutralizing anti-IFN alpha activity in an antiviral assay cells system. From tested EIA positive-competing sera, 5 were shown to be positive by immunoblot and 6 sera were found to contain neutralizing anti-IFN alpha-2b. Four of the 6 neutralizing anti-IFN alpha-2b sera came from patients with thymoma-associated MG. The sera were studied for linear epitope recognition on the IFN alpha-2b molecule by a solid phase binding assay, in which overlapping peptides homologous with the entire IFN alpha-2b sequence were separately synthesized on a nitrocellulose sheet. Peptides number 2 (residues 8-21), 3 (15-28), 6 (33-46), 10 (63-76), 15 (98-112), and 21 (141-154) were immunoreactive. Peptide 21 was apparently associated with antiviral activity, although peptide 21 has not been previously described as an immunogenic determinant on the IFN alpha-2b molecule. These results indicate that neutralizing anti-IFN alpha-2b is often present in MG, particularly in cases of thymoma-associated MG, and recognize a variety of epitopes on the IFN alpha-2b molecule, including those involved in its biological activity. Two groups of IFN epitopes were described associated with patient's age but not with diseases evolution.