773 research outputs found
Influencia de la autoconfianza y el perfil motivacional en el “flujo” en matemáticas
Varios autores consideran que la motivación y el afecto son fundamentales en el aprendizaje de matemáticas, por su influencia en el rendimiento académico de los estudiantes y en su elección de actividades matemáticas. El flujo está asociado a la motivación intrínseca, y se produce cuando los sujetos experimentan alta concentración y disfrute con la actividad que están realizando. La variable afectiva autoconfianza es la creencia sobre la propia competencia matemática. El perfil motivacional se caracteriza mediante la combinación de distintas metas académicas. En este estudio se analiza, a través de cuestionarios, la influencia de la autoconfianza y del perfil motivacional en experiencias de flujo en matemáticas. La muestra está integrada por 161 estudiantes del grado de Maestro de Educación Primaria
Redox-Active Nanomaterials For Nanomedicine Applications
Nanomedicine utilizes the remarkable properties of nanomaterials for the diagnosis, treatment, and prevention of disease. Many of these nanomaterials have been shown to have robust antioxidative properties, potentially functioning as strong scavengers of reactive oxygen species. Conversely, several nanomaterials have also been shown to promote the generation of reactive oxygen species, which may precipitate the onset of oxidative stress, a state that is thought to contribute to the development of a variety of adverse conditions. As such, the impacts of nanomaterials on biological entities are often associated with and influenced by their specific redox properties. In this review, we overview several classes of nanomaterials that have been or projected to be used across a wide range of biomedical applications, with discussion focusing on their unique redox properties. Nanomaterials examined include iron, cerium, and titanium metal oxide nanoparticles, gold, silver, and selenium nanoparticles, and various nanoscale carbon allotropes such as graphene, carbon nanotubes, fullerenes, and their derivatives/variations. Principal topics of discussion include the chemical mechanisms by which the nanomaterials directly interact with biological entities and the biological cascades that are thus indirectly impacted. Selected case studies highlighting the redox properties of nanomaterials and how they affect biological responses are used to exemplify the biologically-relevant redox mechanisms for each of the described nanomaterials
Functional relevance of a non-synonymous substitution in the CD5 gene (V471A) targeted for positive selection in East Asian populations
1 página.-- Póster presentado en el 5º European Workshop on Immune-Mediated Inflammatory Diseases celebrado en Sitges (Barcelona) del 1 al 3 de Diciembre de 2010.Peer reviewe
Cation-exchange porosity tuning in anionic metal-organic frameworks for the selective separation of gases and vapors and for catalysis
A new digital predictive predistorter for behavioral power amplifier linearization
This letter presents a new digital adaptive predistorter
(PD) for power amplifier (PA) linearization based on a nonlinear
auto-regressive moving average (NARMA) structure. The distinctive
characteristic of this PD is its straightforward deduction
from the NARMA PA model, without the need of using an indirect
learningapproachto identify the PD function.The PD itself presents
a NARMA structure, and hence it can be quickly implemented by
means of lookup tables. Single and multicarrier modulated signals
collected from a three-stage LDMOS class AB PA, with a maximum
output power of 48-dBm CW have been used to validate the
linearity performance of this new predictive predistorter.Peer Reviewe
Online score-informed source separation in polyphonic mixtures using instrument spectral patterns
[EN] Soundprism is a real-time algorithm to separate polyphonic music audio into
source signals, given the musical score of the audio in advance. This paper
presents a framework for a Soundprism implementation. A study of the sound
quality of the online score-informed source separation is shown, although a
real-time implementation is not carried out. The system is compound of two
stages: (1) a score follower that matches a MIDI score position to each time frame
of the musical performance; and (2) a source separator based on a nonnegative
matrix factorization approach guided by the score. Real audio mixtures composed of an instrumental quartets were employed to obtain preliminary results
of the proposed system.Ministerio de Economía y Competitividad. Grant Number: TEC2015-67387-C4-{1, 2, 3}-RMuñoz-Montoro, A.; Vera-Candeas, P.; Cortina, R.; Combarro, EF.; Alonso-Jordá, P. (2019). Online score-informed source separation in polyphonic mixtures using instrument spectral patterns. Computational and Mathematical Methods. 1-10. https://doi.org/10.1002/cmm4.1040S11
High levels of standardized ileal digestible amino acids improve feed efficiency in slow-growing pigs at late grower-finisher stage
Slow-growing pigs negatively affect production efficiency in conventional pig farms by increasing the occupation time of the facilities and being a limiting factor for the All-In/All-Out swine production systems. This subset of pigs is usually managed with the rest of the pigs, and their nutrient requirements may not be fulfilled. The purpose of the present study was to compare the productive performance of slow- and fast-growing pigs to different standardized ileal digestible (SID) amino acids (AA) dietary levels at late grower-finisher stage. A total of 84 pigs were weighed, tagged, and classified as slow-growing (SG; n = 48; 24.1 ± 1.38 kg) or fast-growing pigs (FG; n = 36; 42.7 ± 1.63 kg) at 11 weeks of age. Pigs were housed in mixed sex pens (n = 8 SG+6 FG/pen) equipped with feeding stations to record daily feed intake per individual pig. Pigs were assigned to three dietary treatments resulting in a 2 × 3 factorial arrangement at 15 weeks of age. Isoenergetic diets were formulated by increasing the ideal protein profile based on the following SID lysine (Lys) levels: 0.92%, 1.18% and 1.45%. Pigs were weighed bi-weekly until 21 weeks of age. Fast-growing pigs were 33.7 kg heavier, gained 255 g/day and consumed 625.5 g/day more than SG pigs (p 0.05). However, feed conversion ratio was 0.3 lower for SG pigs fed 1.45% SID Lys/AA compared to SG pigs fed 0.92% SID Lys/AA (p = 0.002). Feed conversion ratio was not different within the FG pigs' dietary treatments (p > 0.05). The efficiency of SG pigs may be improved when dietary SID AA levels are increased from 0.92 up to 1.45% SID Lys/AA. Thus, nutrient requirements may vary depending on growth rate at the same age, and SG pigs may require higher dietary SID AA levels than FG pigs to achieve similar productive performance
Heuristic algorithms for power amplifier behavioral modeling
This letter presents the use of two heuristic search algorithms,
named simulated annealing and genetic algorithms, for
the extraction of power amplifier (PA) behavioral model parameters.
Their application in this letter consists in determining the
memory length and the most significant delays of the considered
model structure. Two PA behavioral models have been considered:
an augmented nonlinear moving average model and a nonlinear
auto-regressive moving average model. By using WCDMA signals
measured from a three-stage LDMOS class AB PA, both PA models
were extracted. Finally, results presenting the advantages of using
these heuristic search algorithms are provided.Peer Reviewe
Dye-conjugated complementary lipophilic nucleosides as useful probes to study association processes by fluorescence resonance energy transfer
Modern supramolecular chemistry relies on the combination of diverse analytical techniques that can provide complementary information on complex self-assembly landscapes. Among them, resonance energy transfer, monitored by fluorescence emission spectroscopy, arises as a sensitive and convenient phenomenon to report binding intermolecular interactions. The use of molecular probes labelled with suitable complementary energy-transfer pairs can provide valuable information about the thermodynamics, kinetics and self-sorting characteristics of a particular self-assembled system. The objective of this work is to generate a set of nucleoside FRET probes that can be reliably employed to prove and analyse quantitatively H-bonding interactions between complementary Watson-Crick pairs. We first describe the preparation of a set of lipophilic nucleosides that are linked to a π-conjugated functional fragment. The bases include guanosine and 2-aminoadenosine as purine heterocycles, and cytidine and uridine as complementary pyrimidine bases. The π-conjugated moiety comprises either a short phenylene-ethynylene oligomer, a bithiophene, or a BODIPY dye. We then demonstrate that the last two chromophores constitute an energy donor-acceptor couple and that donor emission quenching can be related to the ratio of molecules bound to the complementary acceptor pair. Hence, fluorescence spectroscopy in combination with resonance energy transfer, is shown here to be a useful tool to study and quantify the association and self-sorting events between complementary and non-complementary nucleosides in apolar aromatic solvents, where the binding strength is considerably high, and sensitive techniques that employ low concentrations are demandedFunding from the European Research Council (ERC-Starting Grant 279548 PROGRAM-NANO) and MINECO (CTQ2014-57729-P) is gratefully acknowledged. E. F. would like to thank the Sharif University of Technology of Iran for financial support. D. S.M. would like to acknowledge Comunidad de Madrid for financial support through contract PEJ16/IND/AI-084
Epigenome-Wide Comparative Study Reveals Key Differences Between Mixed Connective Tissue Disease and Related Systemic Autoimmune Diseases
Mixed Connective Tissue Disease (MCTD) is a rare complex systemic autoimmune disease (SAD) characterized by the presence of increased levels of anti-U1 ribonucleoprotein autoantibodies and signs and symptoms that resemble other SADs such as systemic sclerosis (SSc), rheumatoid arthritis (RA), and systemic lupus erythematosus (SLE). Due to its low prevalence, this disease has been very poorly studied at the molecular level. We performed for the first time an epigenome-wide association study interrogating DNA methylation data obtained with the Infinium MethylationEPIC array from whole blood samples in 31 patients diagnosed with MCTD and 255 healthy subjects. We observed a pervasive hypomethylation involving 170 genes enriched for immune-related function such as those involved in type I interferon signaling pathways or in negative regulation of viral genome replication. We mostly identified epigenetic signals at genes previously implicated in other SADs, for example MX1, PARP9, DDX60, or IFI44L, for which we also observed that MCTD patients exhibit higher DNA methylation variability compared with controls, suggesting that these sites might be involved in plastic immune responses that are relevant to the disease. Through methylation quantitative trait locus (meQTL) analysis we identified widespread local genetic effects influencing DNA methylation variability at MCTD-associated sites. Interestingly, for IRF7, IFI44 genes, and the HLA region we have evidence that they could be exerting a genetic risk on MCTD mediated through DNA methylation changes. Comparison of MCTD-associated epigenome with patients diagnosed with SLE, or Sjogren's Syndrome, reveals a common interferon-related epigenetic signature, however we find substantial epigenetic differences when compared with patients diagnosed with rheumatoid arthritis and systemic sclerosis. Furthermore, we show that MCTD-associated CpGs are potential epigenetic biomarkers with high diagnostic value. Our study serves to reveal new genes and pathways involved in MCTD, to illustrate the important role of epigenetic modifications in MCTD pathology, in mediating the interaction between different genetic and environmental MCTD risk factors, and as potential biomarkers of SADs
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