Interpretación crítica de gráficos estadísticos incorrectos en la sociedad de la comunicación: un desafío para futuros maestros

La formación de profesores para enseñar estadística en educación primaria debe estar orientada a capacitarlos para que desarrollen la cultura estadística en los alumnos de los primeros ni¬veles educativos. La interpretación de gráficos estadísticos forma parte de la “cultura estadística” (statistical literacy) que cualquier ciudadano debe tener para poder desenvolverse plenamente en la actual sociedad de la información. El logro de este objetivo implica que los profesores de matemáticas deben tener dicha cultura y, además, estar capacitados para desarrollarla en sus alumnos. Esto requiere que los programas de formación de maestros contemplen de manera adecuada, tanto el desarrollo de los conocimientos, destrezas y disposiciones que caracterizan la cultura estadística como los conocimientos y competencias didácticas para diseñar procesos de educación estadística idóneos

Dexamethasone Preconditioning Improves the Response of Collagen-Induced Arthritis to Treatment with Short-Term Lipopolysaccharide-Stimulated Collagen-Loaded Dendritic Cells

Background. Pharmacologically modulated dendritic cells (DCs) have been shown to restore tolerance in type II collagen-(CII-) induced arthritis (CIA). We examined the effect of dexamethasone (DXM) administration as a preconditioning agent, followed by an injection of lipopolysaccharide-(LPS-) stimulated and CII-loaded DCs on the CIA course. Methods. After CIA induction, mice pretreated with DXM were injected with 4-hour LPS-stimulated DCs loaded with CII (DXM/4hLPS/CII/DCs). Results. Mice injected with DXM/4hLPS/CII/DCs displayed significantly less severe clinical disease compared to animals receiving 4hLPS/CII/DCs alone or those in which only DXM was administered. Cytokine profile evaluation showed that CD4+ T cells from DXM/4hLPS/CII/DCs and 4hLPS/CII/DCs groups release higher IL-10 levels than those from mice receiving DXM alone or CIA mice. CD4+ T cells from all DC-treated groups showed less IL-17 release when compared to the CIA group. On the contrary, CD4+ T cells from DXM/4hLPS/CII/DCs and 4hLPS/CII/DCs groups released higher IFN-γ levels than those from CIA group. Conclusion. A combined treatment, including DXM preconditioning followed by an inoculation of short-term LPS-stimulated CII-loaded DCs, provides an improved strategy for attenuating CIA severity. Our results suggest that this benefit is driven by a modulation in the cytokine profile secreted by CD4+ T cells

Schizosaccharomyces pombe positive cofactor 4 stimulates basal transcription from TATA-containing and TATA-less promoters through Mediator and transcription factor IIA

The positive cofactor 4 (PC4) protein has an important role in transcriptional activation, which has been proposed to be mediated by transcription factor IIA (TFIIA) and TATA-binding protein-associated factors. To test this hypothesis, we cloned the Schizosaccharomyces pombe PC4 gene and analysed the role of the PC4 protein in the stimulation of basal transcription driven by TATA-containing and TATA-less promoters. Sc. pombe PC4 was able to stimulate basal transcription from several TATA-containing promoters and from the Initiator sequences of the highly transcribed Sc. pombe nmt1 gene. Moreover, it was demonstrated that Sc. pombe PC4 stimulates formation of the transcription preinitiation complex. Activation of transcription by PC4 was dependent on the Mediator complex and TFIIA, but was independent of TATA-binding protein-associated factor. PC4 binds to double-stranded and single-stranded DNA and interacts with TATA-binding protein, TFIIB, TFIIA, Mediator, TFIIH and the transcriptional activator protein VP16

Abortos espontáneos en Hospital de Llay Llay y su relación con labores agrícolas de la madre

Pesticides are chemical substances frequently used in agricultural areas of our country. It is a well established fact that these substances can be harmful to the health, not only of agricultural workers, but also to that of their offspring. The objective of this paper is that of studying the relation between spontaneous abortions and the agricultural occupation of the mother. A descriptive study was carried out assembling the clinical records of those patients presenting spontaneous abortion registered in the maternity book of procedures of the San Francisco de Llay-Llay Hospital between January 2002 and December 2003. The incidence of spontaneous abortion is calculated comparing it to the last available national figures, and the percentage of agricultural occupation of  the mother in relation to the 15 year old and over female population of the same geographic area, according to the 2002 Census. The Z test was performed for comparison of proportions and confidence intervals for the ratio between incidence densities.The incidence rate for spontaneous abortion was 81.02 cases/ 1, 000 live-newborn registrations (RNV) versus 9.5 cases/ 1, 000 live-born registrations in Chile 1996, granting an incidence ratio of 8.5 (CI=6. 72-10. 65).  The percentage of agricultural occupation is higher than the female 15 year old and over population of the same geographic area (pLos pesticidas son sustancias químicas usadas con frecuencia en las zonas agr[colas de nuestro país. Es un hecho bien establecido que estas sustancias pueden ser dañinas para Ia salud no solo del trabajador agrícola sino también para su descendencia. Su objetivo es estudiar Ia asociaci6n entre abortos espontáneos y Ia ocupación agrícola de Ia madre.  Se efectuó un estudio descriptivo, recopilando las fichas clínicas de aquellas pacientes que presentaron aborto espontaneo registrados en el libro de procedimientos de Ia maternidad del Hospital San Francisco de Llay-Llay entre enero del 2002 y diciembre del 2003. Se calcula Ia tasa de incidencia de aborto espontaneo comparándola con las últimas cifras nacionales disponibles, y el porcentaje de ocupación agrícola de Ia madre en relación con Ia población femenina ocupada de 15 años o más de Ia misma (área geográfica  según Censo de/2002. Se realizó la prueba Z para comparación de proporciones, e intervalos de confianza para la razón entre las densidades de incidencia. La tasa de incidencia de aborto espontaneo fue 81,02 casos/1.000 RNV versus 9,5 casos/1.000 RNV en Chile 1996, otorgando una razón de incidencia de 8,5 veces (JC = 6, 72-10,65). El porcentaje de ocupación agrícola es mayor que Ia población femenina ocupada de 15 años o mas de Ia misma área  geográfica. (p < 0,0001). El riesgo de presentar aborto espontáneo en Llay-Llay y Catemu es mayor que el resto del país. La ocupación agrícola está relacionada con un mayor  riesgo de aborto espontaneo, probablemente debida a Ia exposición a pesticidas

Interpretación crítica de gráficos estadísticos incorrectos en la sociedad de la comunicación : un desafío para futuros maestros

La formación de profesores para enseñar estadística en educación primaria debe estar orientada a capacitarlos para que desarrollen la cultura estadística en los alumnos de los primeros niveles educativos. La interpretación de gráficos estadísticos forma parte de la "cultura estadística" (statistical literacy) que cualquier ciudadano debe tener para poder desenvolverse plenamente en la actual sociedad de la información. El logro de este objetivo implica que los profesores de matemáticas deben tener dicha cultura y, además, estar capacitados para desarrollarla en sus alumnos. Esto requiere que los programas de formación de maestros contemplen de manera adecuada, tanto el desarrollo de los conocimientos, destrezas y disposiciones que caracterizan la cultura estadística como los conocimientos y competencias didácticas para diseñar procesos de educación estadística idóneos

Transcription directed by human core promoters with a HomolD box sequence requires DDB1, RECQL and RNA polymerase II machinery

TATA box is the most studied core promoter element and has a well-described transcription mechanism. However, most metazoan promoters lack TATA box and contain other core promoter elements. One of such elements is HomolD box, which was first described in promoters of ribosomal protein genes in Schizosaccharomyces pombe, and studies performed in this model showed that transcription directed by HomolD box is dependent on RNAPII machinery, and the HomolD-binding protein was Rrn7, a component of RNAPI core factor. Nevertheless, the mechanisms that underlie HomolD-dependent transcription are still unknown. The purpose of this study is to determine the mechanism of transcription directed by human HomolD box. By stepwise purification through different ion exchange columns and affinity chromatography, we purified two proteins: DDB1 and RECQL (DNA damage-binding protein 1 and ATP-dependent DNA helicase Q1 respectively). These proteins showed specific HomolD-binding activity and were required f

Rrn7 protein, an RNA polymerase I transcription factor, is required for RNA polymerase II-dependent transcription directed by core promoters with a HomolD box sequence

The region in promoters that specifies the transcription machinery is called the core promoter, displaying core promoter elements (CPE) necessary for establishment of a preinitiation complex and the initiation of transcription. A classical CPE is the TATA box. In fission yeast, Schizosaccharomyces pombe, a new CPE, called HomolD box, was discovered. Collectively, 141 ribosomal protein genes encoding the full set of 79 different ribosomal proteins and more than 60 other housekeeping genes display a HomolD box in the core promoter. Here, we show that transcription directed by the HomolD box requires the RNA polymerase II machinery, including the general transcription factors. Most intriguingly, however, we identify, by DNA affinity purification, Rrn7 as the protein binding to the HomolD box. Rrn7 is an evolutionary conserved member of the RNA polymerase I machinery involved in transcription initiation of core ribosomal DNA promoters. ChIP shows that Rrn7 cross-links to a ribosomal prote

Short-term lipopolysaccharide stimulation induces differentiation of murine bone marrow-derived dendritic cells into a tolerogenic phenotype

Dendritic cells (DCs) are professional, antigen-presenting cells, which induce and regulate T cell reactivity. DCs are crucial in innate and adaptive immune responses, and are also involved in central and peripheral tolerance induction. Tolerance can be mediated by immature and semi-mature DCs expressing low levels of co-stimulator and major histocompatibility complex (MHC) molecules. The aim of this study was to investigate the ability of short-term lipopolysaccharide (LPS) stimulation to modulate the stage of differentiation of bone marrow-derived DCs. For this purpose, DCs obtained from DBA1/lacJ mice were stimulated for four (4hLPS/DCs) or 24 (24hLPS/DCs) hours with LPS, using DCs without stimulation (0hLPS/DCs) as a control. Flow cytometry analysis of 4hLPS/DCs showed intermediate CD40 and MHC class II expression, lower than that of 24hLPS/DCs (fully mature), and greater than that of 0hLPS/DCs (immature). A functional assay showed that 4hLPS/DCs displayed increased endocytotic ab