Gene regulatory networks modelling using a dynamic evolutionary hybrid

<p>Abstract</p> <p>Background</p> <p>Inference of gene regulatory networks is a key goal in the quest for understanding fundamental cellular processes and revealing underlying relations among genes. With the availability of gene expression data, computational methods aiming at regulatory networks reconstruction are facing challenges posed by the data's high dimensionality, temporal dynamics or measurement noise. We propose an approach based on a novel multi-layer evolutionary trained neuro-fuzzy recurrent network (ENFRN) that is able to select potential regulators of target genes and describe their regulation type.</p> <p>Results</p> <p>The recurrent, self-organizing structure and evolutionary training of our network yield an optimized pool of regulatory relations, while its fuzzy nature avoids noise-related problems. Furthermore, we are able to assign scores for each regulation, highlighting the confidence in the retrieved relations. The approach was tested by applying it to several benchmark datasets of yeast, managing to acquire biologically validated relations among genes.</p> <p>Conclusions</p> <p>The results demonstrate the effectiveness of the ENFRN in retrieving biologically valid regulatory relations and providing meaningful insights for better understanding the dynamics of gene regulatory networks.</p> <p>The algorithms and methods described in this paper have been implemented in a Matlab toolbox and are available from: <url>http://bioserver-1.bioacademy.gr/DataRepository/Project_ENFRN_GRN/</url>.</p

Investigating the complexity of respiratory patterns during the laryngeal chemoreflex

<p>Abstract</p> <p>Background</p> <p>The laryngeal chemoreflex exists in infants as a primary sensory mechanism for defending the airway from the aspiration of liquids. Previous studies have hypothesized that prolonged apnea associated with this reflex may be life threatening and might be a cause of sudden infant death syndrome.</p> <p>Methods</p> <p>In this study we quantified the output of the respiratory neural network, the diaphragm EMG signal, during the laryngeal chemoreflex and eupnea in early postnatal (3–10 days) piglets. We tested the hypothesis that diaphragm EMG activity corresponding to reflex-related events involved in clearance (restorative) mechanisms such as cough and swallow exhibit lower complexity, suggesting that a synchronized homogeneous group of neurons in the central respiratory network are active during these events. Nonlinear dynamic analysis was performed using the approximate entropy to asses the complexity of respiratory patterns.</p> <p>Results</p> <p>Diaphragm EMG, genioglossal activity EMG, as well as other physiological signals (tracheal pressure, blood pressure and respiratory volume) were recorded from 5 unanesthetized chronically instrumented intact piglets. Approximate entropy values of the EMG during cough and swallow were found significantly (<it>p </it>< 0.05 and <it>p </it>< 0.01 respectively) lower than those of eupneic EMG.</p> <p>Conclusion</p> <p>Reduced complexity values of the respiratory neural network output corresponding to coughs and swallows suggest synchronous neural activity of a homogeneous group of neurons. The higher complexity values exhibited by eupneic respiratory activity are the result of a more random behaviour, which is the outcome of the integrated action of several groups of neurons involved in the respiratory neural network.</p

Risk management : a strategic advisor for a sound management of a leasing business

Organizations face a very wide range of risks that can impact the outcome of their operations. The constantly increasing risk in nowadays global financial markets emphasizes the importance of correctly estimating future losses, therefore, the management of the leasing company needs to find a good trade-off between business risk, performance risk and financial risk and to have a good strategy to maintain and/or improve the profitability. Although leasing may not be the subject to Basel II. Capital Accord regulatory requirements, in many respects it represents best practices, reflecting a combination of the views of sophisticated lenders represented on the Committee as well as those of the major regulators. Consequently, lenders in the leasing industry frequently look to Basel for benchmarking and insights. This paper aims to illustrate the importance of risk management holistic approach in assessing the risks of a leasing company and we intend to expound that the implementation of an effective risk management process is a key requirement for a modern leasing company that has as priority the need to align profitability, risk profile and asset quality. Also, we will draw attention to the regulatory environment and recent regulatory and supervisory developments with respect to risk management practice

VOLLEYBALL EVOLUTION. ASPECTS IN THE DEVELOPMENT OF THE ROMANIAN VOLLEYBALL

This scientific article presents the inception, evolution and the development of the volleyball game as it happened in time, due to the geopolitical and social influences. Though it appeared in the US it quickly spread worldwide due to a consistent and sustained promotion, but also brought by the US military and the First World War. Romania contributed as well to the development of the game, being a founding member of the International Federation. Nowadays volleyball still is a fashionable game, present in Olympics and all major sports competitions. Evoluția jocului de volei. Aspecte în dezvoltarea voleiului în Romania. Acest articol științific prezintă debutul, evoluția și dezvoltarea jocului de volei, așa cum a avut loc în decursul timpului, datorită influențelor de natura geopolitică și socială. Deși a apărut în US, acesta s-a răspândit în toată lumea atât datorită promovării consistente și susținute cât și prin detașarea trupelor militare americane în decursul primului razboi mondial. Romania a contribuit și ea la dezvoltarea jocului de volei, fiind membru fondator al federației internaționale, participantă la Jocurile Olimpice si la toate competițiile majore. Cuvinte cheie: debut, evoluție, dezvoltare, jocul de volei

Investigating the influence of PFC transection and nicotine on dynamics of AMPA and NMDA receptors of VTA dopaminergic neurons

<p>Abstract</p> <p>Background</p> <p>All drugs of abuse, including nicotine, activate the mesocorticolimbic system that plays critical roles in nicotine reward and reinforcement development and triggers glutamatergic synaptic plasticity on the dopamine (DA) neurons in the ventral tegmental area (VTA). The addictive behavior and firing pattern of the VTA DA neurons are thought to be controlled by the glutamatergic synaptic input from prefrontal cortex (PFC). Interrupted functional input from PFC to VTA was shown to decrease the effects of the drug on the addiction process. Nicotine treatment could enhance the AMPA/NMDA ratio in VTA DA neurons, which is thought as a common addiction mechanism. In this study, we investigate whether or not the lack of glutamate transmission from PFC to VTA could make any change in the effects of nicotine.</p> <p>Methods</p> <p>We used the traditional AMPA/NMDA peak ratio, AMPA/NMDA area ratio, and KL (Kullback-Leibler) divergence analysis method for the present study.</p> <p>Results</p> <p>Our results using AMPA/NMDA peak ratio showed insignificant difference between PFC intact and transected and treated with saline. However, using AMPA/NMDA area ratio and KL divergence method, we observed a significant difference when PFC is interrupted with saline treatment. One possible reason for the significant effect that the PFC transection has on the synaptic responses (as indicated by the AMPA/NMDA area ratio and KL divergence) may be the loss of glutamatergic inputs. The glutamatergic input is one of the most important factors that contribute to the peak ratio level.</p> <p>Conclusions</p> <p>Our results suggested that even within one hour after a single nicotine injection, the peak ratio of AMPA/NMDA on VTA DA neurons could be enhanced.</p