Quantitative Analysis of the Effective Functional Structure in Yeast Glycolysis

Yeast glycolysis is considered the prototype of dissipative biochemical oscillators. In cellular conditions, under sinusoidal source of glucose, the activity of glycolytic enzymes can display either periodic, quasiperiodic or chaotic behavior. In order to quantify the functional connectivity for the glycolytic enzymes in dissipative conditions we have analyzed different catalytic patterns using the non-linear statistical tool of Transfer Entropy. The data were obtained by means of a yeast glycolytic model formed by three delay differential equations where the enzymatic speed functions of the irreversible stages have been explicitly considered. These enzymatic activity functions were previously modeled and tested experimentally by other different groups. In agreement with experimental conditions, the studied time series corresponded to a quasi-periodic route to chaos. The results of the analysis are three-fold: first, in addition to the classical topological structure characterized by the specific location of enzymes, substrates, products and feedback regulatory metabolites, an effective functional structure emerges in the modeled glycolytic system, which is dynamical and characterized by notable variations of the functional interactions. Second, the dynamical structure exhibits a metabolic invariant which constrains the functional attributes of the enzymes. Finally, in accordance with the classical biochemical studies, our numerical analysis reveals in a quantitative manner that the enzyme phosphofructokinase is the key-core of the metabolic system, behaving for all conditions as the main source of the effective causal flows in yeast glycolysis.Comment: Biologically improve

Nanomaterials for reversion of multidrug resistance in cancer: a new hope for an old idea?

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Conocimientos psicológicos, competencia conductual y estilo docente

Entre las distintas variables que intervienen en el proceso de instrucción, cada vez se le presta mayor atención al papel que la personalidad del profesor y su estilo de interacción en el aula, tienen en dicho proceso (Getzels y Jackson, 1963). Por otra parte, dado que hay suficiente evidencia empírica de que las ideas y creencias estables del profesor inciden directamente en los análisis explicativos que realiza (Schneider y Grasha, 1983), adquiere especial interés el estudio de los conocimientos y concepciones explicativas sobre los comportamientosde sus alumnos. En la presente investigación se evaluó en un grupo de 19 profesores, 1. sus conocimientos e interpretaciones sobre el comportamiento, 2. las estrategias que utilizaban en la resolución de problemas comportamentales en el aula, 3. la percepción que tenían sobre la gravedad de las conductas disruptivas y,4. la percepción que tenían de la eficacia de las estrategia que utilizaban. Tras la aplicación de un programa de entrenamiento en la resolución de problemas de comportamiento en el aula, se volvieron a evaluar las variables anteriores. Se presentan y discuten los resultados, analizando sus implicaciones sobre los estilos docentes

Revisiting 30 years of biofunctionalization and surface chemistry of inorganic nanoparticles for nanomedicine

FP7-PEOPLE-2013-IOF, Project no. 626386 PEst-OE/SAU/U10009/2011-14 MAT2011-26851-C02-01In the last 30 years we have assisted to a massive advance of nanomaterials in material science. Nanomaterials and structures, in addition to their small size, have properties that differ from those of larger bulk materials, making them ideal for a host of novel applications. The spread of nanotechnology in the last years has been due to the improvement of synthesis and characterization methods on the nanoscale, a field rich in new physical phenomena and synthetic opportunities. In fact, the development of functional nanoparticles has progressed exponentially over the past two decades. This work aims to extensively review 30 years of different strategies of surface modification and functionalization of noble metal (gold) nanoparticles, magnetic nanocrystals and semiconductor nanoparticles, such as quantum dots. The aim of this review is not only to provide in-depth insights into the different biofunctionalization and characterization methods, but also to give an overview of possibilities and limitations of the available nanoparticles.publishersversionpublishe

The Metabolic Core and Catalytic Switches Are Fundamental Elements in the Self-Regulation of the Systemic Metabolic Structure of Cells

[Background] Experimental observations and numerical studies with dissipative metabolic networks have shown that cellular enzymatic activity self-organizes spontaneously leading to the emergence of a metabolic core formed by a set of enzymatic reactions which are always active under all environmental conditions, while the rest of catalytic processes are only intermittently active. The reactions of the metabolic core are essential for biomass formation and to assure optimal metabolic performance. The on-off catalytic reactions and the metabolic core are essential elements of a Systemic Metabolic Structure which seems to be a key feature common to all cellular organisms. [Methodology/Principal Findings] In order to investigate the functional importance of the metabolic core we have studied different catalytic patterns of a dissipative metabolic network under different external conditions. The emerging biochemical data have been analysed using information-based dynamic tools, such as Pearson's correlation and Transfer Entropy (which measures effective functionality). Our results show that a functional structure of effective connectivity emerges which is dynamical and characterized by significant variations of bio-molecular information flows. [Conclusions/Significance] We have quantified essential aspects of the metabolic core functionality. The always active enzymatic reactions form a hub –with a high degree of effective connectivity- exhibiting a wide range of functional information values being able to act either as a source or as a sink of bio-molecular causal interactions. Likewise, we have found that the metabolic core is an essential part of an emergent functional structure characterized by catalytic modules and metabolic switches which allow critical transitions in enzymatic activity. Both, the metabolic core and the catalytic switches in which also intermittently-active enzymes are involved seem to be fundamental elements in the self-regulation of the Systemic Metabolic Structure.Consejo Superior de Investigaciones Cientificas (CSIC),grant 201020I026. Ministerio de Ciencia e Innovacion (MICINN). Programa Ramon y Cajal. Campus de Excelencia Internacional CEI BioTIC GENIL, grant PYR-2010-14. Junta de Andalucia, grant P09-FQM-4682

Big five, self-regulation, and coping strategies as predictors of achievement emotions in undergraduate students

The study focused on the analysis of linear relations between personality, self-regulation, coping strategies and achievement emotions. The main objective was to establish a model of linear, empirical, associative to infer needs and proposals for intervening in emotional health in the dierent profiles of university students. A total of 642 undergraduate students participated in this research. Evidence of associative relations between personality factors, self-regulation and coping strategies was found. The neuroticism factor had a significant negative associative relationship with Self-Regulation both globally and in its factors; especially important was its negative relation to decision making, and coping strategies focused in emotion. The results of Structural Equation Model showed an acceptable model of relationships, in each emotional context. Results and practical implications are discussed

Systems Biology of Tissue-Specific Response to Anaplasma phagocytophilum Reveals Differentiated Apoptosis in the Tick Vector Ixodes scapularis

Anaplasma phagocytophilum is an emerging pathogen that causes human granulocytic anaplasmosis. Infection with this zoonotic pathogen affects cell function in both vertebrate host and the tick vector, Ixodes scapularis. Global tissue-specific response and apoptosis signaling pathways were characterized in I. scapularis nymphs and adult female midguts and salivary glands infected with A. phagocytophilum using a systems biology approach combining transcriptomics and proteomics. Apoptosis was selected for pathway-focused analysis due to its role in bacterial infection of tick cells. The results showed tissue-specific differences in tick response to infection and revealed differentiated regulation of apoptosis pathways. The impact of bacterial infection was more pronounced in tick nymphs and midguts than in salivary glands, probably reflecting bacterial developmental cycle. All apoptosis pathways described in other organisms were identified in I. scapularis, except for the absence of the Perforin ortholog. Functional characterization using RNA interference showed that Porin knockdown significantly increases tick colonization by A. phagocytophilum. Infection with A. phagocytophilum produced complex tissue-specific alterations in transcript and protein levels. In tick nymphs, the results suggested a possible effect of bacterial infection on the inhibition of tick immune response. In tick midguts, the results suggested that A. phagocytophilum infection inhibited cell apoptosis to facilitate and establish infection through up-regulation of the JAK/STAT pathway. Bacterial infection inhibited the intrinsic apoptosis pathway in tick salivary glands by down-regulating Porin expression that resulted in the inhibition of Cytochrome c release as the anti-apoptotic mechanism to facilitate bacterial infection. However, tick salivary glands may promote apoptosis to limit bacterial infection through induction of the extrinsic apoptosis pathway. These dynamic changes in response to A. phagocytophilum in I. scapularis tissue-specific transcriptome and proteome demonstrated the complexity of the tick response to infection and will contribute to characterize gene regulation in ticks.This research was supported by grants BFU2011-23896, the EU FP7 ANTIGONE project number 278976, the Oklahoma Agricultural Experiment Grant 1669 and the Walter R. Sitlington Endowed Chair for Food Animal Research to KMK. NA and RCG were funded by MEC, Spain. RS was supported by the project Postdok\_BIOGLOBE (CZ.1.07/2.3.00/30.0032) and the Grant 13-12816P (GA CR). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.S

Personal Self-Regulation, Learning Approaches, Resilience and Test Anxiety in Psychology Students

La autorregulación personal se ha conceptuado como una meta-habilidad, de orden meta-motivacional y meta-afectivo. Esta investigación pretendió establecer las relaciones de asociación e interdependencia con otras variables motivacionales-afectivas relevantes. Participaron un total de 121 alumnos de 2º y 4º curso de Psicología, de la Universidad de Almería (España). Se realizaron análisis correlacionales bivariados de Pearson, ANOVAs y MANOVAs. Los resultados mostraron una relación significativa de ferencial entre la autorregulación personal y cada tipo de enfoque de aprendizaje, positiva con la tenacidad y con control resiliente, y negativa con la preocupación. Se evidencia el valor de esta construcción psicoeducativa presagio de las variables estudiadas.Personal self-regulation has been conceptualized as meta-hability, a meta-motivational and meta-affective variable. The objective of this investigation was to establish association and interdependence relationships with other important motivational-affective variables. There were 121 participants in the study, all of them students from the second and fourth year of the Psychology degree program at the University of Almería (Spain). Pearson bivariate correlational analyses, ANOVAs and MANOVAs were car ried out. Self-regulation was shown to have a signifi cant relationship with each type of learning approach, positive with tenacity and with resilient control, and a negative relationship with worry. Personal self-regulation is shown to have value as a presage psychological construct within the study of motivational-affective variables in Education

The role of personal self-regulation and regulatory teaching to predict motivational-affective variables, achievement and satisfaction: A structural model

The present investigation examines how personal self-regulation (presage variable) and regulatory teaching (process variable of teaching) relate to learning approaches, strategies for coping with stress, and self-regulated learning (process variables of learning) and, finally, how they relate to performance and satisfaction with the learning process (product variables). The objective was to clarify the associative and predictive relations between these variables, as contextualized in two different models that use the presage-process-product paradigm (the Biggs and DEDEPRO models). A total of 1101 university students participated in the study. The design was cross-sectional and retrospective with attributional (or selection) variables, using correlations and structural analysis. The results provide consistent and significant empirical evidence for the relationships hypothesized, incorporating variables that are part of and influence the teaching¿learning process in Higher Education. Findings confirm the importance of interactive relationships within the teaching¿learning process, where personal selfregulation is assumed to take place in connection with regulatory teaching. Variables that are involved in the relationships validated here reinforce the idea that both personal factors and teaching and learning factors should be taken into consideration when dealing with a formal teaching¿learning context at university