Sorties de la minorité

Existe-t-il vraiment une différence si marquée, claire et évidente entre fuite et autonomie, entre la quête désespérée d’une une issue, comme celle des animaux protagonistes de tant de récits de Kafka, pour qui la survie n’est possible qu’en se cachant dans l’obscurité d’une tanière ou en recourant au mimétisme, ou comme celle des détenus d’une prison ou d’un camp, et la sortie de la minorité décrite par Kant comme un passage volontaire et conscient à la lumière, un processus d’éclairement ? Et si la différence était, en fait, plus ambiguë, plus subtile qu’il n’y paraît

Diels-Alder Chemistry to Develop Self-Healing Epoxy Resins and Composites Thereof

Self-healing polymers are a class of smart materials able to recover after sustaining damage. A family of thermosetting epoxy resins, containing Diels-Alder (DA) adducts in the epoxy precursor backbone, has been prepared and characterized. The DA adducts can be reversibly cleaved and reformed under the appropriate thermal conditions, and this feature has been exploited to produce intrinsically self-repairing materials. This chapter focuses on the effects of different structural features, such as average number of cross-linking functionality and molecular mobility of epoxy precursors, on the efficiency of healing process. High cross-linking density and molecular stiffness improve mechanical performances, such as elastic modulus and glass transition temperature, and allow fabrication of self-healing fiber-reinforced composites by conventional manufacturing technologies. Within this chapter, the molecular design, the preparation, and the evaluation of properties of self-healing epoxy and its composites have been discussed

From traumatic childhood to cocaine abuse: the critical function of the immune system

Background: Experiencing traumatic childhood is a risk factor for developing substance use disorder (SUD), but the mechanisms that underlie this relationship have not been determined. Adverse childhood experiences affect the immune system and the immune system mediates the effects of psychostimulants. However, whether this system is involved in the etiology of SUD in individuals who have experience early life stress is unknown. Methods:In this study, we performed a series of ex vivo and in vivo experiments in mice and humans to define the function of the immune system in the early-life stress-induced susceptibility to the neurobehavioral effects of cocaine. Results: We provide evidence that exposure to social-stress (S-S) at an early age permanently sensitizes the peripheral (splenocytes) and brain (microglia) immune responses to cocaine in mice. In the brain, microglial activation in the ventral tegmental area (VTA) of S-S mice was associated with functional alterations in dopaminergic neurotransmission, as measured by whole-cell voltage clamp recordings in dopamine (DA) neurons. Notably, preventing immune activation during the S-S exposure reverted the effects of DA in the VTA and the cocaine-induced behavioral phenotype to control levels. In humans, cocaine modulated Toll-like receptor 4-mediated innate immunity, an effect that was enhanced in cocaine addicts who had experienced a difficult childhood. Conclusions Collectively, our findings demonstrate that sensitization to cocaine in early-life-stressed individuals involves brain and peripheral immune responses and that this mechanism is shared between mice and humans

A rate-distortion theory for gene regulatory networks and its application to logic gate consistency

ABSTRACT Motivation: A gene regulatory network in which the modes (activation/ inhibition) of the transcriptional regulations are known and in which gene expression assumes boolean values can be treated as a system of linear equations over a binary field, i.e. as a constraint satisfaction problem for an information code. Results: For currently available gene networks, we show in this article that the distortion associated with the corresponding information code is much lower than expected from null models, and that it is close to (when not lower than) the Shannon bound determined by the ratedistortion theorem. This corresponds to saying that the distribution of regulatory modes is highly atypical in the networks, and that this atypicality greatly helps in avoiding contradictory transcriptional actions. Choosing a boolean formalism to represent the gene networks, we also show how to formulate criteria for the selection of gates that maximize the compatibility with the empirical information available on the transcriptional regulatory modes. Proceeding in this way, we obtain in particular that non-canalizing gates are upper-bounded by the distortion, and hence that the boolean gene networks are more canalizing than expected from null models

Effect of Aqueous Extract of Maca Addition to an Extender for Chilled Canine Semen

Antioxidant supplementation has been proposed as a new strategy to improve the long-term preservation of semen. The aim of this study was to evaluate the effect of Maca supplementation of semen extender on quality-related canine semen parameters during cooling. Ejaculates from nine dogs were cooled for 7 days in the absence (control group) or in the presence of 10, 20 and 50 μL/mL of an aqueous extract of Maca. Sperm were evaluated for sperm viability, motility, DNA fragmentation and lipid peroxidation after 3 h, 24 h, 4 days and 7 days of storage. The addition of 10 μL/mL of Maca preserved sperm DNA and plasma membrane integrity at 3 h and increased sperm curvilinear velocity after 24 h. Treatment with 20 and 50 μL/mL of Maca increased the percentage of hyperactivated sperm after 3 h. Moreover, semen treated with 20 μL/mL of Maca decreased lipid peroxidation at 24 h. A significant reduction of sperm DNA and plasma membrane integrity as well as of kinetics parameters between 3 and 24 h of refrigerated storage with the higher concentration tested was observed. Although Maca was not able to protect canine semen with extended refrigeration storage time, it increased hyperactivation and preserved DNA integrity in short-term storage

Monitoring of self-healing composites: a nonlinear ultrasound approach

Self-healing composites using a thermally mendable polymer, based on Diels–Alder reaction were fabricated and subjected to various multiple damage loads. Unlike traditional destructive methods, this work presents a nonlinear ultrasound technique to evaluate the structural recovery of the proposed self-healing laminate structures. The results were compared to computer tomography and linear ultrasound methods. The laminates were subjected to multiple loading and healing cycles and the induced damage and recovery at each stage was evaluated. The results highlight the benefit and added advantage of using a nonlinear based methodology to monitor the structural recovery of reversibly cross-linked epoxy with efficient recycling and multiple self-healing capability

Correlation between olfactory function, age, sex, and cognitive reserve index in the Italian population

Purpose: Loss of smell decreases the quality of life and contributes to the failure in recognizing hazardous substances. Given the relevance of olfaction in daily life, it is important to recognize an undiagnosed olfactory dysfunction to prevent these possible complications. Up to now, the prevalence of smell disorders in Italy is unknown due to a lack of epidemiological studies. Hence, the primary aim of this study was to evaluate the prevalence of olfactory dysfunction in a sample of Italian adults. Methods: Six hundred and thirty-three participants (347 woman and 286 men; mean age 44.9 years, SD 17.3, age range 18-86) were recruited from 10 distinct Italian regions. Participants were recruited using a convenience sapling and were divided into six different age groups: 18-29 years (N = 157), 30-39 years (N = 129), 40-49 years (N = 99), 50-59 years (N = 106), > 60 years (N = 142). Olfactory function, cognitive abilities, cognitive reserve, and depression were assessed, respectively, with: Sniffin' Sticks 16-item Odor Identification Test, Montreal Cognitive Assessment, Cognitive Reserve Index, and the Beck Depression Inventory. Additionally, socio-demographic data, medical history, and health-related lifestyle information were collected. Results: About 27% of participants showed an odor identification score < 12 indicating hyposmia. Multiple regression analysis revealed that OI was significantly correlated with age, sex, and cognitive reserve index, and young women with high cognitive reserve index showing the highest olfactory scores. Conclusion: This study provides data on the prevalence of olfactory dysfunction in different Italian regions

Shared genetic risk between eating disorder- and substance-use-related phenotypes:Evidence from genome-wide association studies

First published: 16 February 202

De l' "histoire théorétique et conjecturale"

Dugald Stewart, dans l’Account of Life and Writings of Adam Smith , définit la méthode d’enquête d’Adam Smith comme « histoire théorétique ou conjecturelle ». Dugald Stewart affirme que la méthode d’Adam Smith est très proche de celle utilisée par David Hume dans son Histoire naturelle de la religion, et de ce que « certains écrivains français » ont appelé « Histoire raisonnée »