Introduction of cyclofem once-a-month injectable contraceptive in Mexico.

A large introductory study of Cyclofem, a once-a-month injectable contraceptive, was conducted in three Mexican provinces. A total of 3457 healthy women participated: 640 women from rural areas (community-based component) and 2817 women from urban and suburban areas (health center-based component). A total of 20,316 women-months of treatment experience were accumulated during a one year period. Cyclofem proved its use-effectiveness (pregnancy rate of 0.03%) and its safety under routine service conditions of family planning facilities in Mexico. The overall life table continuation rate at 1 year was 26.1%. Higher continuation rates were observed in the community-based component (36.6%) as compared to the health center component (23.7%). The most common reason for method discontinuation was change of address. Only 15% of the discontinuations were attributable to the injectable contraceptive method, with the overall 1 year discontinuation rate for bleeding problems (including amenorrhea) was < 11%. These observations underscore the importance of appropriate counseling and follow-up measures, providing convenient access to repeat injections, and other service delivery issues related to continuation of Cyclofem. The results of this trial have once again demonstrated that Cyclofem is a highly effective method with an acceptable side effect profile. In addition, the study provided the elements for its approval by local health authorities and its inclusion into the Ministry of Health Family Planning Program.

PIP: The effectiveness and continuation rates associated with the once-a-month injectable contraceptive Cyclofem were investigated in an introductory trial conducted in three Mexican provinces (Sinaloa, Guanajuato, and Veracruz). Cyclofem contains 25 mg of medroxyprogesterone acetate and 5 mg of estradiol cypionate. A total of 3457 women (640 women from rural communities and 2817 from urban and suburban family planning centers) were enrolled and 20,316 woman-months of treatment experience were accumulated during the 12-month study period. The mean age of study participants was 23.6 years; 70% had previously used at least one contraceptive method. There was only one pregnancy (rate, 0.03%). The overall life-table continuation rate at 1 year was 26.1%, but this rate was higher in the community-based group (36.9%) than in the health center group (22.4%). This discrepancy is presumed to reflect the greater access of clinic clients to other contraception options. Continuation was highest among women 30-34 years of age, those with low levels of education, women with five or more children, and those who did not want more children. Only 14% of discontinuations were method-related. The 1-year discontinuation rate for bleeding problems, including amenorrhea, was 10.2%. These findings indicate Cyclofem is a safe, effective method appropriate for inclusion in Mexico's Ministry of Health Family Planning Program.

A test of the spatial-frequency explanation of the Müller-Lyer illusion.

Previous investigations have shown that the response of spatial-frequency-specific channels in the human visual system is differentially affected by adaptation to gratings of distinct spatial frequencies and/or orientations. A study is reported of the effects of adaptation to vertical or horizontal gratings of a high or a low spatial frequency on the extent of the Brentano form of the Müller-Lyer illusion in human observers. It is shown that the illusion decreases after adaptation to vertical gratings of low spatial frequency, but seems unaffected otherwise. These results are consistent with the notion of visual channels that are spatial-frequency and orientation specific, and support the argument that the Müller-Lyer illusion may be due primarily to lower-spatial-frequency components in the Fourier spectra of the image.

La manipulacion de imagenes en tareas de memoria reconstructiva. / Manipulation of images in reconstructive memory jobs

El problema de este estudio fue el de la representacion y manipulacion de imagenes producidas por material verbal y su relacion con la reconstruccion en la memoria.Se trabajo con 30 sujetos, los cuales tuvieron que representarse figuras partiendo de instrucciones verbales de lineas, y extraer de estas imagenes informacion adicional que no se encontraba en los estimulos. Se obtuvieron cuatro correlaciones por medio del coeficiente de correlacion de rango de Kendall, las cuales se hicieron entre la cantidad de informacion contenida en los estimulos y la cantidad de aciertos de los sujetos, encontrandose correlaciones negativas significativas en todos los casos. La relacion negativa significativa hallada entre la cantidad de aciertos, indica un limite en los sujetos para el manejo y manipulacion de imagenes.Este estudio sugiere que la imaginacion no puede ser entendida como un proceso aislado de representacion de eventos, sino como un proceso activo de traer del pasado al presente informacion que no fue aprendida directamente, por medio de un proceso activo de reconstruccion

Tiempo de reaccion y conteo cerrado de objetos: su relacion con la reconstruccion en la memoria. / Reaction time and the counting of objects: its relation to the reconstruction in the memory

Se hizo un experimento con cuatro condiciones donde participaron noventa y cinco sujetos en la primera y treinta en cada una de las siguientes. Fueron dos condiciones de conteo cerrado de objetos, es decir, en ausencia fisica del estimulo y dos de conteo abierto, es decir, en presencia fisica de los estimulos a contar.La hipotesis fue que en el conteo cerrado, se reconstruye una imagem y se cuenta y esto conlleva un tiempo directamente relacionado con la cantidad de objetos a contar. Esta hipotesis se vio apoyada en todas las correlaciones obtenidas entre el tiempo empleado y la cantidad de objetos, las cuales tuvieron una p < 0.005. Los tiempos obtenidos en las condiciones de conteo cerrado y los obtenidos en los de conteo abierto fueron diferentes. Las correlaciones encontradas en conteo abierto apoyaron la hipotesis de la memoria reconstructiva, como un proceso semejante al que se realiza en conteo cerrado, donde se ha reconstruido una imagen