Acceptability And Performance Of The Levonorgestrel-releasing Intrauterine System (mirena) In Campinas, Brazil.

The objectives of this study were to evaluate the acceptability of the LNG-IUS Mirena(R), when offered as an additional option in a free choice context, and to evaluate the possibility of using this method in women with increased bleeding wanting an IUD and in copper IUD users requesting removal of the device for bleeding problems. A total of 256 women chose Mirena and were accepted into the study during the enrollment period. This represents 23.3% of all new acceptors of contraceptive methods in the clinic during the same period. Discontinuations were fairly evenly distributed among expulsion, bleeding changes, pain, and personal reasons. Bleeding changes were decreased bleeding, oligomenorrhea or amenorrhea. Comparing the performance in the group of women who chose the LNG-IUS as a first option with those having heavy bleeding, the only difference found was a higher expulsion rate in the group with bleeding problems. No pregnancies occurred and continuation rate was slightly over 75% in the total sample and in both groups. The characteristics of the LNG-IUS (Mirena) allow predicting that this method can effectively contribute to the increase in contraceptive options when introduced to family planning programs in Brazil.6259-6

Sensitivity of Edge Detection Methods for Quantifying Cell Migration Assays

Quantitative imaging methods to analyze cell migration assays are not standardized. Here we present a suite of two-dimensional barrier assays describing the collective spreading of an initially-confined population of 3T3 fibroblast cells. To quantify the motility rate we apply two different automatic image detection methods to locate the position of the leading edge of the spreading population after [Image: see text], [Image: see text] and [Image: see text] hours. These results are compared with a manual edge detection method where we systematically vary the detection threshold. Our results indicate that the observed spreading rates are very sensitive to the choice of image analysis tools and we show that a standard measure of cell migration can vary by as much as 25% for the same experimental images depending on the details of the image analysis tools. Our results imply that it is very difficult, if not impossible, to meaningfully compare previously published measures of cell migration since previous results have been obtained using different image analysis techniques and the details of these techniques are not always reported. Using a mathematical model, we provide a physical interpretation of our edge detection results. The physical interpretation is important since edge detection algorithms alone do not specify any physical measure, or physical definition, of the leading edge of the spreading population. Our modeling indicates that variations in the image threshold parameter correspond to a consistent variation in the local cell density. This means that varying the threshold parameter is equivalent to varying the location of the leading edge in the range of approximately 1–5% of the maximum cell density

Concepto de objetivo de una tarea matemática de futuros maestros

Dentro de la línea de formación de profesores, en este trabajo presentamos aspectos de una investigación con futuros maestros de primaria, donde nos enfocamos en comprender cómo los estudiantes de la Universidad de Granada interpretan la meta como elemento de análisis de una tarea matemática escolar, enmarcada dentro del Análisis Didáctico como herramienta funcional en la formación inicial. Se ha seguido una metodología cualitativa, a través del análisis de contenido. Los antecedentes evidencian la importancia de las tareas escolares para favorecer el aprendizaje de las matemáticas, y los resultados nos muestran la dificultad que presentan los futuros maestros para establecer y definir la meta de una tarea matemática escolar

Functionally-separate intracellular ca2+ stores in smooth muscle

In smooth muscle, release via the inositol 1,4,5-trisphosphate (Ins(1,4,5)P3R) and ryanodine receptors (RyR) on the sarcoplasmic reticulum (SR) controls oscillatory and steady-state cytosolic Ca2+ concentrations ([Ca2+]c). The interplay between the two receptors, itself determined by their organization on the SR, establishes the time course and spatial arrangement of the Ca2+ signal. Whether or not the receptors are co-localized or distanced from each other on the same store or whether they exist on separate stores will significantly affect the Ca2+ signal produced by the SR. To date these matters remain unresolved. The functional arrangement of the RyR and Ins(1,4,5)P3R on the SR has now been examined in isolated single voltage-clamped colonic myocytes. Depletion of the ryanodine-sensitive store, by repeated application of caffeine, in the presence of ryanodine, abolished the response to Ins(1,4,5)P3, suggesting that Ins(1,4,5)P3R and RyR share a common Ca2+store. Ca2+ release from the Ins(1,4,5)P3R did not activate Ca2+-induced Ca2+ release at the RyR. Depletion of the Ins(1,4,5)P3-sensitive store, by the removal of external Ca2+, on the other hand, caused only a small decrease (∼26%) in caffeine-evoked Ca2+transients, suggesting that not all RyR exist on the common store shared with Ins(1,4,5)P3R. Dependence of the stores on external Ca2+ for replenishment also differed; removal of external Ca2+ depleted the Ins(1,4,5)P3-sensitive store but caused only a slight reduction in caffeine-evoked transients mediated at RyR. Different mechanisms are presumably responsible for the refilling of each store. Refilling of both Ins(1,4,5)P3-sensitive and caffeine-sensitive Ca2+ stores was inhibited by each of the SR Ca2+ ATPase inhibitors thapsigargin and cyclopiazonic acid. These results may be explained by the existence of two functionally distinct Ca2+ stores; the first expressing only RyR and refilled from [Ca2+]c, the second expressing both Ins(1,4,5)P3R and RyR and dependent upon external Ca2+ for refilling