Los futuros maestros aprenden cuando preparan sus clases de matemáticas

La asignatura Didáctica de las Matemáticas tiene por objetivo que los alumnos, que de aquí en adelante llamaremos futuros maestros, sean capaces de planificar y llevar a la práctica actividades que permitan a sus futuros alumnos lograr en el área de matemática aprendizajes significativos. Esto implica que deban poner en juego conocimientos de matemáticas, de didáctica en general, y en particular las que responden al paradigma constructivista y su puesta en práctica en el desarrollo de una clase, pudiendo elegir otros modelos didácticos, según lo requiera el proceso de aprendizaje del alumno y en relación con los contenidos a aprender

Linear arrays of InGaAs quantum dots on nanostructured GaAs-on-Si substrates

Linear arrays of high-quality quantum dots (QD) integrated in Si are an ideal platform in exploring the manipulation and transmission of quantum information. Understanding QD self-organization mechanisms on substrates compatible with Si technology is therefore of great practical importance. Here we demonstrate the epitaxial growth of linear arrays of InAs and InGaAs QDs from As2 and In molecular beams on bare and GaAs-coated Si(0 0 1) substrates, patterned by high-resolution laser interference nanolithography. Atomic force microscopy, in combination with high-resolution scanning and transmission electron microscopies, show that these arrays exhibit an improvement in growth selectivity, lateral order and size uniformity of the QDs when a pseudomorphic 1 nm-thick GaAs buffer layer is grown prior to InAs deposition. In addition, preferential nucleation of InxGa1-xAs QDs along the 〈1 1 0〉 -oriented edges of the nanostructured GaAs-on-Si(0 0 1) substrate results from In adatom migration from (1 1 1) to (0 0 1) nanofacets and the erosion of the wetting and buffer layers caused by the Ga-In intermixing at the step edge during the Stranski-Krastanov transition. These are key elements in the formation of linear arrays of coherent QDs, which differ in morphology and structure from those obtained on both GaAs(0 0 1) and Si(0 0 1) planar surface

Percepción y reconocimiento facial: bases teóricas de las ruedas de reconocimiento

Frecuentemente testigos de un suceso deben describir al sospechoso. En muchas ocasiones destacan aspectos sobresalientes como una cicatriz o un rasgo facial muy destacado. ¿Cómo se produce la percepción facial? La psicología de la percepción explica este proceso que analizamos a continuación. Se discute si la percepción es analítica u holística, el fenómeno de la ilusión de Thatcher y el peso de los esquemas representacionales.Witnesses of an event often must describe the suspect. Frequently they include highlights like a scar or a prominent facial feature. How facial perception occurs? Perception psychology explains this process. We analyze the importance of analytical perception, holistic perception, Thatcher Illusion and representational schemes to explain i

Growth of (Pb,La)TiO3 and ZnO thin films on (100)InP by PulseD Laser deposition

[ES] Se ha estudiado el proceso de depósito mediante ablación con láser de láminas delgadas de PbTiO3 modificado con La (PLT) y ZnO sobre (100)InP. Para el PLT se han depositado láminas intermedias de óxidos dieléctricos (CeO2, ZrO2, SrO, YSZ, MgO, y SrTiO3) necesarias para la protección de la superficie del substrato. En cada caso se han establecido las condiciones experimentales (presión de oxígeno, temperatura del substrato, densidad de energía del pulso láser y limpieza de la superficie del substrato) necesarias para obtener láminas cristalinas con orientación preferente. En la heteroestructura PLT/YSZ/(100)InP se estudian los cambios de composición y morfología a lo largo del perfil de la heteroestructura, a fin de investigar los procesos involucrados en el crecimiento de estos óxidos sobre el (100)InP.[EN] The oriented growth of PbLaTiO3 (PLT) and ZnO thin films on (100)InP has been studied, including the influence of buffer oxide layers (CeO2, ZrO2, SrO, YSZ, MgO, and SrTiO3) on the final texture of PLT film obtained. In each case the oxygen pressure, substrate temperature, energy fluence and substrate surface conditions required to obtain a crystalline and preferentially oriented phase have been established. The composition and morphological changes related to the PLT/YSZ/(100)InP heterostructure profile have been studied in order to investigate the processes involved in the growth of these oxides on (100)InP.Este trabajo ha sido financiado por CICyT y por la Comunidad Autónoma de Madrid con de los proyectos TIC96- 1039 y 07T/0032/1997 respectivamente. E. V. está subvencionado por la Agencia Española de Cooperación Internacional a través de una beca doctoral Mutis.Peer reviewe

Decision Support in Patients with mild Alzheimer’s Disease.

Introduction: Making advantageous decisions is a key competence of individuals of all ages. However, previous studies reported a reduction of this competence in patients with neurodegenerative diseases such as Alzheimer’s disease, which is explained by impairments of executive functions such as cognitive flexibility or working memory. While previous findings from healthy participants with reduced executive functions showed that support can improve decision making under risk, the study at hand aimed to investigate this effect in patients with mild Alzheimer’s disease (mAD). Method: A group of elderly individuals diagnosed with mAD (n = 14; mean Mini-Mental State Examination, MMSE = 24.14, SD = 3.18) and a group of healthy age-matched controls (n = 14; mean MMSE = 29.29, SD = 1.98) performed the Game of Dice Task (GDT) three times (t0, t1, t2) with intervals of five to nine days between each: The standard GDT plus other neurocognitive tasks (t0), the GDT with decision support (t1), and again the standard GDT (t2). Results: At any time, mAD patients made more disadvantageous decisions than controls. However, the decision-making performance of mAD patients improved significantly with decision support. Interestingly, when the standard GDT was played again (t2), mAD patients’ performance remained similar to the performance in the GDT with decision support (t1). GDT performance correlated consistently with executive function measures in the control group, but only at t0 in the mAD group. Conclusions: The findings indicate that supportive information about the riskiness of options can compensate for mAD-related deficits in decision making under risk. Thus, decision support can improve the quality of mAD patients’ decisions. Further, it may prevent mAD patients from making highly risky decisions in similar situations in the future. The persistence of decision support should be further investigated as it has relevant implications for everyday decisions that include risks.pre-print577 K

Penetration of levofloxacin into the anterior chamber (aqueous humour) of the human eye after intravenous administration

©Springer-Verlag 2007. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ This document is the Accepted, version of a Published Work that appeared in final form in European Journal of Clinical Microbiology and Infectious Diseases. To access the final edited and published work see https://doi.org/ 10.1007/s10096-006-0241-9In the study presented here, levofloxacin con centrations in serum samples and the aqueous humour (AH) of 16 patients undergoing cataract extraction were measured in order to determine the penetration characteristics of levofloxacin into the AH of the non-inflamed human eye. Cataract removal was performed at various times (from 90 to 270 min) after the end of a 30-min intravenous infusion of 500 mg of levofloxacin. Serum samples were obtained 1 h after the end of levofloxacin administration (C max ); AH and a second serum sample were taken simultaneously during the operation, and the concentrations of levofloxacin in AH (C AH ) and serum (C S) were determined using a rapid high-performance liquid chromatography assay. The mean Cmax was 6.07 μg/ml (range 3.75–9.53 μg/ml, SD 1.83). The mean CAH at the first hour following levofloxacin administration was 1.37 μg/ml (range 1.17–1.6 μg/ml, SD 0.22) and the mean ratio (R=CAH /C S ) was 0.26 (range 0.24–0.3, SD 0.02). The mean CAH at 125–270 min following levofloxacin administration was 1.39 μg/ml (range 0.82–1.98 μg/ml, SD 0.33) and the mean R was 0.3 (range 0.15–0.53, SD 0.11). Of 16 patients, 15 had a CAH of >1 μg/ml 1 h after levofloxacin administration. In conclusion, 1 h after administration of 500 mg of levofloxacin, the levels obtained were higher than the MIC at which 90% of methicillin-susceptible Staphylococcus aureus and certain gram-negative bacteria strains are inhibited

Simultaneous preconcentration and determination of trace metals (V, Ni, Ti, and Ga) in environmental samples by high resolution continuum source electrothermal atomic absorption spectrometry.

In this work is presented a simple, sensitive, low-cost method for direct and simultaneous determination of V, Ti, Ni and Ga by electrothermal atomic absorption spectrometer (ETAAS) in aqueous environmental samples (tap and seawater samples). The system is based on the retention of the analyte on a novel adsorbent material based on the coupling of magnetic nanoparticles (MNPs) and graphene oxide (GO) functionalised with methylthiosalicylate (MTS) that provides selectivity to interact with transition metals in solution, M@GO -MTS. The detection limits achieved with the method were 0.9 μg L-1 for Ti, 0.6 μg L-1 for V, 0.04 μg L-1 for Ga, 0.75 μg L-1 for Ni. The accuracy of the proposed method was demonstrated by analysing two certified reference materials and by determining the analyte content in spiked environmental water samples. The results obtained using this method were in good agreement with the certified values of the standard reference materials and the recoveries for the spiked tap water and seawater samples were between 90% to 120%.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Synthesis of a novel magnetic nanomaterial for the development of a multielemental speciation method of lead, mercury, and vanadium via HPLC‑ICP MS

A new magnetic functionalized material based on graphene oxide magnetic nanoparticles named by us, M@GO-TS, was designed and characterized in order to develop a magnetic solid-phase extraction method (MSPE) to enrich inorganic and organic species of lead, mercury, and vanadium. A flow injection (FI) system was used to preconcentrate the metallic and organometallic species simultaneously, while the ultra-trace separation and determination of the selected species were achieved by high-performance liquid chromatography coupled to inductively coupled plasma mass spectrometry (HPLC-ICP MS). Therefore, preconcentration and separation/determination processes were automated and conducted separately. To the best of our knowledge, this is the first method combining an online MSPE and HPLC-ICP MS for multielemental speciation. Under the optimized conditions, the enrichment factor obtained for PbII, trimethyllead (TML), HgII, methylmercury (MetHg), and VV was 27. The calculated LOD for all studied species were as follows: 5 ng L−1, 20 ng L−1, 2 ng L−1, 10 ng L−1, and 0.4 ng L−1, respectively. The RSD values calculated with a solution containing 0.5 μg L−1 of all species were between 2.5 and 4.5%. The developed method was validated by analyzing Certified Reference Materials TMDA 64.3 for total concentration and also by recovery analysis of the species in human urine from volunteers and a seawater sample collected in Málaga. The t statistical test showed no significant differences between the certified and found values for TMDA 64.3. All the recoveries obtained from spiked human urine and seawater samples were close to 100%. All samples were analyzed using external calibration. The developed method is sensitive and promising for routine monitoring of the selected species in environmental waters and biological samples.Funding for open access charge: Universidad de Málaga/CBU

A Study of PLA Thin Film on SS 316L Coronary Stents Using a Dip Coating Technique

The dip coating process is one of the recognized techniques used to generate polymeric coatings on stents in an easy and low-cost way. However, there is a lack of information about the influence of the process parameters of this technique on complex geometries such as stents. This paper studies the dip coating process parameters used to provide a uniform coating of PLA with a 4–10 µm thickness. A stainless-steel tube (AISI 316L) was laser-cut, electropolished, and dip-coated in a polylactic acid (PLA) solution whilst changing the process parameters. The samples were characterized to examine the coating’s uniformity, thickness, surface roughness, weight, and chemical composition. FTIR and Raman investigations indicated the presence of PLA on the stent’s surface, the chemical stability of PLA during the coating process, and the absence of residual chloroform in the coatings. Additionally, the water contact angle was measured to determine the hydrophilicity of the coating. Our results indicate that, when using entry and withdrawal speeds of 500 mm min−1 and a 15 s immersion time, a uniform coating thickness was achieved throughout the tube and in the stent with an average thickness of 7.8 µm.We gratefully thank Consejo Nacional de Humanidades, Ciencia y Tecnología (Conahcyt) (CVU: 931068) and Tecnologico de Monterrey for providing scholarship and tuition to the lead author of the Ph.D. degree program. We thank Ciencia de Frontera Consejo Nacional de Humanidades, Ciencias y Tecnologías: CF-2023-I-2901. The Advanced Manufacturing research group (Tecnologico de Monterrey) supported the acquisition of materials. This research did not receive any other specific grant from funding agencies in the public, commercial, or not-for-profit sectors.Departamento de Ingeniería Química, Química Física y Ciencias de los Materiale

Identification of clusters in multifocal electrophysiology recordings to maximize discriminant capacity (patients vs. control subjects)

Purpose To propose a new method of identifying clusters in multifocal electrophysiology (multifocal electroretinogram: mfERG; multifocal visual-evoked potential: mfVEP) that conserve the maximum capacity to discriminate between patients and control subjects. Methods The theoretical framework proposed creates arbitrary N-size clusters of sectors. The capacity to discriminate between patients and control subjects is assessed by analysing the area under the receiver operator characteristic curve (AUC). As proof of concept, the method is validated using mfERG recordings taken from both eyes of control subjects (n = 6) and from patients with multiple sclerosis (n = 15). Results Considering the amplitude of wave P1 as the analysis parameter, the maximum value of AUC = 0.7042 is obtained with N = 9 sectors. Taking into account the AUC of the amplitudes and latencies of waves N1 and P1, the maximum value of the AUC = 0.6917 with N = 8 clustered sectors. The greatest discriminant capacity is obtained by analysing the latency of wave P1: AUC = 0.8854 with a cluster of N = 12 sectors. Conclusion This paper demonstrates the effectiveness of a method able to determine the arbitrary clustering of multifocal responses that possesses the greatest capacity to discriminate between control subjects and patients when applied to the visual field of mfERG or mfVEP recordings. The method may prove helpful in diagnosing any disease that is identifiable in patients’ mfERG or mfVEP recordings and is extensible to other clinical tests, such as optical coherence tomography