Noise Processing by MicroRNA-Mediated Circuits: the Incoherent Feed-Forward Loop, Revisited

The intrinsic stochasticity of gene expression is usually mitigated in higher eukaryotes by post-transcriptional regulation channels that stabilise the output layer, most notably protein levels. The discovery of small non-coding RNAs (miRNAs) in specific motifs of the genetic regulatory network has led to identifying noise buffering as the possible key function they exert in regulation. Recent in vitro} and in silico studies have corroborated this hypothesis. It is however also known that miRNA-mediated noise reduction is hampered by transcriptional bursting in simple topologies. Here, using stochastic simulations validated by analytical calculations based on van Kampen's expansion, we revisit the noise-buffering capacity of the miRNA-mediated Incoherent Feed Forward Loop (IFFL), a small module that is widespread in the gene regulatory networks of higher eukaryotes, in order to account for the effects of intermittency in the transcriptional activity of the modulator gene. We show that bursting considerably alters the circuit's ability to control static protein noise. By comparing with other regulatory architectures, we find that direct transcriptional regulation significantly outperforms the IFFL in a broad range of kinetic parameters. This suggests that, under pulsatile inputs, static noise reduction may be less important than dynamical aspects of noise and information processing in characterising the performance of regulatory elements.Comment: 25 pages (Main Text and Supplementary Information), 5 figure

Noise processing by microRNA-mediated circuits: The Incoherent Feed-Forward Loop, revisited

The intrinsic stochasticity of gene expression is usually mitigated in higher eukaryotes by post-transcriptional regulation channels that stabilise the output layer, most notably protein levels. The discovery of small non-coding RNAs (miRNAs) in specific motifs of the genetic regulatory network has led to identifying noise buffering as the possible key function they exert in regulation. Recent in vitro and in silico studies have corroborated this hypothesis. It is however also known that miRNA-mediated noise reduction is hampered by transcriptional bursting in simple topologies. Here, using stochastic simulations validated by analytical calculations based on van Kampen's expansion, we revisit the noise-buffering capacity of the miRNA-mediated Incoherent Feed Forward Loop (IFFL), a small module that is widespread in the gene regulatory networks of higher eukaryotes, in order to account for the effects of intermittency in the transcriptional activity of the modulator gene. We show that bursting considerably alters the circuit's ability to control static protein noise. By comparing with other regulatory architectures, we find that direct transcriptional regulation significantly outperforms the IFFL in a broad range of kinetic parameters. This suggests that, under pulsatile inputs, static noise reduction may be less important than dynamical aspects of noise and information processing in characterising the performance of regulatory elements

The role of affect in failure in mathematics at the university level: the tertiary crisis

The tertiary transition between secondary school and university appears to be an insurmountable struggle for many students. This is also the case, surprisingly, in a certain sense, of students enrolled in Mathematics degree courses, and therefore students considered “gifted” with respect to mathematics. This case seems particularly interesting from an affective point of view: these students often live failure in mathematics as a tragedy, and – above all – initially they are not able to interpret their failure. For these reasons, it appears crucial to investigate which role is played by emotions in the emergence and management of this crisis, and how the students’ view of mathematics and their self-perception develop in the tertiary crisis period

The first-time phenomenon: successful students' mathematical crisis in secondary-tertiary transition

The huge difficulties related to the transition from secondary to tertiary mathematics are documented by several official data. The analysis of these difficulties is a main issue in educational research at undergraduate level. It is of particular interest the case of the students who choose mathematics as a major. In fact, for the most part, they are students considered excellent in mathematics during secondary school, they seem to have the cognitive resources to succeed, but, in many cases, they encounter several difficulties during their university experience. Therefore, it appears particularly interesting to study also the affective sources and consequences of these difficulties. With this aim, we developed a qualitative and narrative study focused on students’ reflec- tions about their mathematical difficulties in the university experience

Post-Traumatic Growth in Cancer Survivors: Narrative Markers and Functions of The Experience\u27s Transformation

The concept that a traumatic experience, such as a cancer, can lead to a positive change and transformation of self, life and relationships was named as post-traumatic growth (PTG). A large amount of research measured PTG in cancer survivors arguing an interpretation of the construct as an outcome. Recently, qualitative research shows different types of narrative of PTG, but the narrative markers and their functions of transformation remain still unclear. Within a mixed-method, we aim to highlight the narrative markers and their transformative functions, underlying the PTG, within 12 cancer survivors’ narratives with medium/high and medium/low level of PTG. A redemptive sequence analysis was carried out. In the narratives with high/medium PTG we find a specific transformative function on-thinking focused transformation founded on the change/expansion of the own internal criteria to interpret the relationship with the world centralizing the self in the present and future; in the narratives with medium/low PTG we find an on-acting focused transformation, founded on the change of the operational procedures aimed to live centered on the present and on its moments

Qualitative attributes of meat from Teramana goat kids, an Italian native breed of the Abruzzo region

The aim of this work was the characterization of the qualitative aspects of meat obtained from Teramana goats, an Italian indigenous breed of the Abruzzo region. Specifically, the study included a comparison with meat samples deriving from Saanen goat kids reared in the same environment and applying the same feeding protocol