63 research outputs found

    Appraisals, emotions and emotion regulation: An integrative approach

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    The present work aims to investigate the relation between appraisals, emotions, and emotion regulation strategies by creating a structural equation model which integrates these three aspects of the emotion process. To reach this aim, Italian students (N = 610) confronted with their high school diploma examination completed a questionnaire 3 weeks before the beginning of the exam. Results showed that they experienced primarily three types of emotions—anxiety/fear, frustration/powerlessness, positive emotions—which were related to specific appraisal profiles. Importantly, these appraisal profiles and emotions were associated with the use of different strategies for regulating emotions: anxiety/fear was associated with focusing on the exam, drug use, and an inability to distance oneself from the exam; frustration/powerlessness, with use of suppression, distancing, and drugs; positive emotion, with reappraisal and problem focused strategies. The effectiveness of these different strategies will be discussed

    Impact of Sarcoplasmic Reticulum Calcium Release on Calcium Dynamics and Action Potential Morphology in Human Atrial Myocytes: A Computational Study

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    Electrophysiological studies of the human heart face the fundamental challenge that experimental data can be acquired only from patients with underlying heart disease. Regarding human atria, there exist sizable gaps in the understanding of the functional role of cellular Ca2+ dynamics, which differ crucially from that of ventricular cells, in the modulation of excitation-contraction coupling. Accordingly, the objective of this study was to develop a mathematical model of the human atrial myocyte that, in addition to the sarcolemmal (SL) ion currents, accounts for the heterogeneity of intracellular Ca2+ dynamics emerging from a structurally detailed sarcoplasmic reticulum (SR). Based on the simulation results, our model convincingly reproduces the principal characteristics of Ca2+ dynamics: 1) the biphasic increment during the upstroke of the Ca2+ transient resulting from the delay between the peripheral and central SR Ca2+ release, and 2) the relative contribution of SL Ca2+ current and SR Ca2+ release to the Ca2+ transient. In line with experimental findings, the model also replicates the strong impact of intracellular Ca2+ dynamics on the shape of the action potential. The simulation results suggest that the peripheral SR Ca2+ release sites define the interface between Ca2+ and AP, whereas the central release sites are important for the fire-diffuse-fire propagation of Ca2+ diffusion. Furthermore, our analysis predicts that the modulation of the action potential duration due to increasing heart rate is largely mediated by changes in the intracellular Na+ concentration. Finally, the results indicate that the SR Ca2+ release is a strong modulator of AP duration and, consequently, myocyte refractoriness/excitability. We conclude that the developed model is robust and reproduces many fundamental aspects of the tight coupling between SL ion currents and intracellular Ca2+ signaling. Thus, the model provides a useful framework for future studies of excitation-contraction coupling in human atrial myocytes

    Cancer Biomarker Discovery: The Entropic Hallmark

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    Background: It is a commonly accepted belief that cancer cells modify their transcriptional state during the progression of the disease. We propose that the progression of cancer cells towards malignant phenotypes can be efficiently tracked using high-throughput technologies that follow the gradual changes observed in the gene expression profiles by employing Shannon's mathematical theory of communication. Methods based on Information Theory can then quantify the divergence of cancer cells' transcriptional profiles from those of normally appearing cells of the originating tissues. The relevance of the proposed methods can be evaluated using microarray datasets available in the public domain but the method is in principle applicable to other high-throughput methods. Methodology/Principal Findings: Using melanoma and prostate cancer datasets we illustrate how it is possible to employ Shannon Entropy and the Jensen-Shannon divergence to trace the transcriptional changes progression of the disease. We establish how the variations of these two measures correlate with established biomarkers of cancer progression. The Information Theory measures allow us to identify novel biomarkers for both progressive and relatively more sudden transcriptional changes leading to malignant phenotypes. At the same time, the methodology was able to validate a large number of genes and processes that seem to be implicated in the progression of melanoma and prostate cancer. Conclusions/Significance: We thus present a quantitative guiding rule, a new unifying hallmark of cancer: the cancer cell's transcriptome changes lead to measurable observed transitions of Normalized Shannon Entropy values (as measured by high-throughput technologies). At the same time, tumor cells increment their divergence from the normal tissue profile increasing their disorder via creation of states that we might not directly measure. This unifying hallmark allows, via the the Jensen-Shannon divergence, to identify the arrow of time of the processes from the gene expression profiles, and helps to map the phenotypical and molecular hallmarks of specific cancer subtypes. The deep mathematical basis of the approach allows us to suggest that this principle is, hopefully, of general applicability for other diseases

    Ionic liquids: Industrial applications to green chemistry.

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    Active Pharmaceutical Ingredients-Ionic Liquids (APIs-ILs), when compared to Active Pharmaceutical Ingredients Hydrochloride (APIs-HCl), exhibits modified solubility, increased thermal stability and significant enhancement in the efficiency of APIs. To produce and demonstrate application of green ionic liquid form of the APIs, we prepared ammonium, phosphonium and choline couple with flufenamic acid. Their physical properties such as thermal stability, melting points and solubility were studied. Flufenamic ionic liquids undoubtedly represent a promising group of ionic liquids. As these new ionic liquids are halogen–free, it is expected that such new compounds will prove useful in further studies centered on active pharmaceutical ingredients ionic liquids

    Characterisation and sediment-source linkages of intertidal sediment of the UK's north Sefton Coast using magnetic and textural properties: Findings and limitations

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    Sediment pathways and links to offshore processes are considered in the textural and magnetic characteristics of sediments of the intertidal flats and salt marshes of the north Sefton Coast, UK. In addition, sediment from a range of intertidal, marine and fluvial locations within the northwest region has similarly been characterised. Subsequently, the characteristics of these regional sediments, using a multivariate statistical approach of R- and Q-mode factor analyses, have been used to investigate the sediment transport pathways of the north Sefton Coast sediment. The benefits of fractionating sediment samples have been observed, and by using combinations of textural and isothermal remanent magnetic measurements, specific environments within the research have been successfully differentiated and characterised. Linkages between potential sediment source areas have also been established on a particle size-related basis. © Springer-Verlag 2011
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