Determination of diagnostic standards on saturated soil extracts for cut roses grown in greenhouses.

This work comprises the theoretical determination and validation of diagnostic standards for the analysis of saturated soil extracts for cut rose flower crops (Rosa spp.) growing in the Bogota Plateau, Colombia. The data included 684 plant tissue analyses and 684 corresponding analyses of saturated soil extracts, all collected between January 2009 and June 2013. The tissue and soil samples were selected from 13 rose farms, and from cultivars grafted on the 'Natal Briar' rootstock. These concurrent samples of soil and plant tissues represented 251 production units (locations) of approximately 10,000 m2 distributed across the study area. The standards were conceived as a tool to improve the nutritional balance in the leaf tissue of rose plants and thereby define the norms for expressing optimum productive potential relative to nutritional conditions in the soil. To this end, previously determined diagnostic standard for rose leaf tissues were employed to obtain rates of foliar nutritional balance at each analyzed location and as criteria for determining the diagnostic norms for saturated soil extracts. Implementing this methodology to foliar analysis, showed a higher significant correlation for diagnostic indices. A similar behavior was observed in saturated soil extracts analysis, becoming a powerful tool for integrated nutritional diagnosis. Leaf analyses determine the most limiting nutrients for high yield and analyses of saturated soil extracts facilitate the possibility of correcting the fertigation formulations applied to soils or substrates. Recommendations are proposed to improve the balance in soil-plant system with which the possibility of yield increase becomes more probable. The main recommendations to increase and improve rose crop flower yields would be: continuously check pH values of SSE, reduce the amounts of P, Fe, Zn and Cu in fertigation solutions and carefully analyze the situation of Mn in the soil-plant system.

[Estimation of the parasitemia in Trypanosoma cruzi human infection: high parasitemias are associated with severe and fatal congenital Chagas disease]. / Estimación de la parasitemia en la infección humana por Trypanosoma cruzi: las altas parasitemias están asociadas con la severa y fatal enfermedad de Chagas congenita.

The aim of this study was to validate the method of microhematocrit tube, as a rapid method to estimate the parasitemia in blood and to associate the parasites concentration with the morbidity and mortality of new born children with congenital Chagas diseases. Our results were determined experimentally and shown that the detection limit of the microhematocrit tube method is 40 parasites/ml when at least one of the four observed tubes is positive. Besides, it was also established that when the four examined tubes are positive the parasitemia in blood reaches more than 100 parasites/ml. It is important to highlight the modification made by our laboratory in the microscopic observation of the microhematocrit tubes with respect to the methodology used by previous investigators. A positive association exists between a high number of parasites in blood and the morbi-mortality of the newly born children with congenital chagas. The results of positive association between the parasitic load and the morbility and mortality could constitute an argument to understand the possible role of the parasite in the pathology of the disease.

[Estimation of the number of institutionalized elderly in Chile]. / Adultos mayores institucionalizados en Chile: cómo saber cuántos son?

BACKGROUND: Elderly people (>60 years) in Chile represented 11.4% (n=1,717,478) of the total population in 2002. The group with disabilities or mental problems is increasing and there is no reliable information about the number of institutionalized elderly subjects. AIM: To estimate the number of elderly people living in residences for long term care and their main characteristics. PATIENTS AND METHODS: Chilean Census does not provide exact information about institutional care, therefore we developed a "proxy" indicator of the percentage of institutionalized elderly (those living in "collective residences with more than 5 elderly persons and in which they represent more than 25% of the residents". This proxy has a R2=0.9859 with the true value of institutionalized persons for those Latin-American countries with exact value in census data at CELADE. RESULTS: Using the proxy we found that institutionalized elderly population had increased from 14,114 (1992) to 26,854 (2002) and is projected to reach 83,500 (2025). In 2002, there were 1,668 institutions (37.4% informal care). In the Metropolitan Area, there were 804 institutions (14,178 elderly persons) and 40.3% of these were registered at the Ministry of Health. The proportion of institutionalized elderly subjects was 1.56% of the total elderly population; this proportion increased from 0.87% in subjects 60-74 years old to 2.5% among subjects aged 75-84 years and 6.1% in subjects 85 years old and over. Among subjects living in institutions, 60.9 were women, 21% were married, 35% were single, approximately 50% receive a pension and around 15% were handicapped. CONCLUSIONS: Institutional care affects a small percentage of elderly population, but it will increase in the near future. The main characteristics of institutionalized elderly subjects are not well known. We propose to create a formal Registry of these institutions and to include Nursing Homes and hospitals in type of housing of future Censuses.

Algunos problemas que se presentan en la selección del modelo de mortalidad más apropiado para la estimación indirecta de la mortalidad infantil / Infant mortality trends from retrospective information: problems in the selection of mortality models

En este trabajo se analizan algunos de los problemas presentados al derivar estimaciones de mortalidad infatil de las probabilidades de muerte obtenidas mediante la aplicación de la técnica de Coale-Trussell a la proporción de hijos fallecidos según edad de la madre, derivada de datos de censos o encuestas. Estos problemas se explican por la necesidad de aceptar un modelo de mortalidad por edad. Se señalan algunos criterios para la selección del modelo más apropiado mediante el uso de información de Estadísticas Vitales y encuestas y, finalmente, se plantea que una alternativa para estudiar la tendencia de la mortalidad en la niñez es la selección de un indicador menos afectado por la estructura de la mortalidad por edad, como: q(2), q(3) ó q(5)