Filosofía, Matemáticas y Educación: una perspectiva histórico-cultural en Educación Matemática-Philosophy, Mathematics and Education: A Cultural-Historical Perspective on Mathematics Education

Sobre la base de planteamientos epistemológicos derivados de la teoría de la actividad, en este artículo se argumenta en favor de una postura sobre el conocimiento matemático que posiciona los procesos individuales y sociales de su constitución como polos de una dualidad dialéctica mediada por los sistemas de prácticas socialmente compartidos. Con base en estos planteamientos, y tomando en consideración la noción de configuración epistémica, en la segunda parte se presenta una caracterización de los sistemas de práctica matemática. Como resultado de lo anterior, se presentan elementos teóricos y metodológicos que se han mostrado potentes en algunos estudios de las prácticas matemáticas de los individuos en condiciones institucionales específicas

Identification of regulatory variants associated with genetic susceptibility to meningococcal disease.

Non-coding genetic variants play an important role in driving susceptibility to complex diseases but their characterization remains challenging. Here, we employed a novel approach to interrogate the genetic risk of such polymorphisms in a more systematic way by targeting specific regulatory regions relevant for the phenotype studied. We applied this method to meningococcal disease susceptibility, using the DNA binding pattern of RELA - a NF-kB subunit, master regulator of the response to infection - under bacterial stimuli in nasopharyngeal epithelial cells. We designed a custom panel to cover these RELA binding sites and used it for targeted sequencing in cases and controls. Variant calling and association analysis were performed followed by validation of candidate polymorphisms by genotyping in three independent cohorts. We identified two new polymorphisms, rs4823231 and rs11913168, showing signs of association with meningococcal disease susceptibility. In addition, using our genomic data as well as publicly available resources, we found evidences for these SNPs to have potential regulatory effects on ATXN10 and LIF genes respectively. The variants and related candidate genes are relevant for infectious diseases and may have important contribution for meningococcal disease pathology. Finally, we described a novel genetic association approach that could be applied to other phenotypes

Plasma lipid profiles discriminate bacterial from viral infection in febrile children

Fever is the most common reason that children present to Emergency Departments. Clinical signs and symptoms suggestive of bacterial infection ar

Plasma lipid profiles discriminate bacterial from viral infection in febrile children

Fever is the most common reason that children present to Emergency Departments. Clinical signs and symptoms suggestive of bacterial infection are often non-specific, and there is no definitive test for the accurate diagnosis of infection. The 'omics' approaches to identifying biomarkers from the host-response to bacterial infection are promising. In this study, lipidomic analysis was carried out with plasma samples obtained from febrile children with confirmed bacterial infection (n = 20) and confirmed viral infection (n = 20). We show for the first time that bacterial and viral infection produces distinct profile in the host lipidome. Some species of glycerophosphoinositol, sphingomyelin, lysophosphatidylcholine and cholesterol sulfate were higher in the confirmed virus infected group, while some species of fatty acids, glycerophosphocholine, glycerophosphoserine, lactosylceramide and bilirubin were lower in the confirmed virus infected group when compared with confirmed bacterial infected group. A combination of three lipids achieved an area under the receiver operating characteristic (ROC) curve of 0.911 (95% CI 0.81 to 0.98). This pilot study demonstrates the potential of metabolic biomarkers to assist clinicians in distinguishing bacterial from viral infection in febrile children, to facilitate effective clinical management and to the limit inappropriate use of antibiotics

Efectividad de las salidas frontal y lateral para la prueba de pista 300 metros CRI, patinaje de velocidad sobre ruedas

We analyzed and evaluated biomechanically, from the left sagittal plane, the front output (SF) and the side outlet (SL) in speed track individual time trial (CRI) of eleven (11) skaters penultimate (RSV) using the software SIMI°Twinner Pro software and SPSS (version 19); which it allowed to determine that the SF is more effective than the SL for the development of tests CRI RSV skating.Foram analisados e avaliados biomecanicamente, a partir do plano sagital esquerdo, a saída frontal (SF) ea saída lateral (SL) na velocidade rastrear contra-relógio individual (CRI) de onze (11) patinadores penúltimo (RSV) usando o software SIMI° Twinner software Pro e SPSS (versão 19); que permitiu determinar que o SF é mais eficaz do que o SL para o desenvolvimento de testes de CRI RSV patinagem.Se analizó y evaluó biomecánicamente, desde el plano sagital izquierdo, la Salida Frontal (SF) y la Salida Lateral (SL) en pruebas de velocidad de pista Contra el Reloj Individual (CRI), de once (11) Patinadores de Velocidad Sobre Ruedas (VSR), empleando el Software SIMI°Twinner Pro y el software SPSS (versión 19); lo que permitió determinar que la SF es la más efectiva que la SL para el desarrollo de las pruebas CRI en el patinaje de VSR

Effect of calcium and anti-browning agents on total phenols and antioxidant capability of 'Packham's Triumph' pears packed in modified atmosphere

The effect of calcium propionate (PCa) 1% p/v, ethylenediaminetetraacetic acid (EDTA) 0.1% p/v, cysteine (CIS) 0.5% p/v and citric acid (AC) 0.5% p/v were evaluated on the total phenol content, antioxidant capability and respiration rate of 'Packham's Triumph' pear wedges, packed in modified atmosphere (MA, 8-11% O2 and 14-16% CO2 after 6 days of storage) and stored at 5°C for 8 days. The treatments were control (washed with water at 5°C, MA), PCa + EDTA + CIS + AC (MA), and PCa + EDTA + CIS (MA). The evaluations were performed on days 1, 3 and 8 after processing. The respiration rate of the control samples was 42% lower than the pear wedges treated with PCa and anti-browning agents (10-12 mg CO2 kg⁻¹ h⁻¹) during 8 days of storage. On days 3 and 8, the pear wedges treated with PCa + EDTA + CIS + AC and PCa + EDTA + CIS showed respiration rates 55% higher than the control samples. On the other hand, the total phenol content was preserved along the storage period, even though it was 27% lower than the content in peeled fresh fruit (265 mg 100 gfw-1). At the end of the storage period, the PCa + EDTA + CIS showed the highest phenolic content (214 mg 100 gfw-1), while it was lower in the other treatments (146 mg 100 gfw-1). According to the antioxidant capability, non-significantly statistical differences were shown throughout shelf-life, except those wedges treated with PCa + EDTA + CIS whose antioxidant capability was increased by 67%. After the minimally processing operations chemical agent immersions and MA packaging, the total phenol content was diminished compared to the initial fresh flesh fruit. In addition, MA could have a high impact on gas atmosphere inside the packages and preservation of the functional quality of 'Packham's Triumph' pear wedges because no differences were detected among treatments

Registration of ‘CI0947bmr’ Sorghum

The sorghum [Sorghum bicolor (L.) Moench] cultivar CI0947bmr (Reg. No. CV-137, PI 672153) was jointly developed and released by the Centro Nacional de Tecnología Agropecuaria y Forestal (CENTA) research program in El Salvador and the Texas A&M Agrilife Research sorghum breeding program in 2013. CI0947bmr is a brown midrib (bmr), dual-purpose sorghum selected for productivity in Central American environments. CI0947bmr was developed from a pedigree breeding program, and it was derived from a BC1F2 population of the pedigree B03292bmr/Tortillero//Tortillero. All generation advancement and selection were completed in San Andres, El Salvador. To confirm performance of the line, CI0947bmr was evaluated in replicated yield trials in 10 Central American environments ranging from Panama to Guatemala in 2010 and 2011. Compared with Sureno (a non-bmr dual-purpose sorghum cultivar grown in the region), CI0947bmr is similar in maturity, dry biomass yield, grain yield, and composition, with lower concentration of lignin and higher in vitro dry matter digestibility and total digestible nutrients. Given these characteristics, CI0947bmr can be used for forage production (grazing and silage) or for grain production with the post-harvest plant residue suitable as forage. In addition, producers can save seed for replanting. This cultivar is designed to provide small livestock producers and dairies in Central America with access to sorghum forage with improved forage quality without sacrificing dry matter yield, grain yield, or grain quality