Convergent evolution of small molecule pheromones in Pristionchus nematodes

The small molecules that mediate chemical communication between nematodes—so-called ‘nematode-derived-modular-metabolites’ (NDMMs)—are of major interest because of their ability to regulate development, behavior, and life-history. Pristionchus pacificus nematodes produce an impressive diversity of structurally complex NDMMs, some of which act as primer pheromones that are capable of triggering irreversible developmental switches. Many of these NDMMs have only ever been found in P. pacificus but no attempts have been made to study their evolution by profiling closely related species. This study brings a comparative perspective to the biochemical study of NDMMs through the systematic MS/MS- and NMR-based analysis of exo-metabolomes from over 30 Pristionchus species. We identified 36 novel compounds and found evidence for the convergent evolution of complex NDMMs in separate branches of the Pristionchus phylogeny. Our results demonstrate that biochemical innovation is a recurrent process in Pristionchus nematodes, a pattern that is probably typical across the animal kingdom.

Análise de uma Estrutura de Concreto Armado e proposição de reforço para correção de falhas estruturais: Estudo de Caso

The reinforced concrete structures degradation even before reaching useful life, is a very recurrent process in buildings, and it is necessary to execute corrective techniques to strengthen the structural elements. Therefore, it is noted that research in this field is very important to civil engineering. Consequently, the present study consisted in performing a static and dynamic analysis of a school building that presented structural flaws to identify the causes of it and propose a rehabilitation solution. Through the static analysis of the structure, performed with the CAD/TQS program, it was verified that the slabs and beams of the building were mostly executed with a thickness lower than ideal and that, in some slabs, the deflection obtained were higher than allowable. Through modal analysis, performed with Altair HyperWorks program, it was verified that the fourth, fifth and sixth vibration modes of the structure did not meet the ELS-VE, since they present natural frequencies between the critical range indicated by NBR 6118 (ABNT, 2014), thus showing the occurrence of excessive vibration. As a result, a rehabilitation solution was proposed, using steel beams, which were calculated according to the methodology of NBR 8800 (ABNT, 2008) and, verified with the aid of Altair HyperWorks program. This methodology for strengthening the concrete structure was verified with the aid of the platform Altair HyperWorks, where it was concluded that the steel beam used are able to solve the problem with the excessive deflection in the slabs without harming the displacements of the beans who support them, maintaining unaltered the natural frequencies.

Maintenance pharmacotherapy of atopic dermatitis

Atopic dermatitis (AD) - multifactorial inflammatory disease of skin characterized by pruritus, chronic recurrent process and age-related features of localization and morphology of lesions. This is one of most spread disease of skin up to 40%, meeting in all countries, in both sexes, in different age groups. The aim. Prevention of severe forms of AD and complications. Methods. To estimate the degree of atopic dermatitis was used international scale SCORAD (Scoring of Atopic Dermatitis). Results and discussion. At present time the pathogenesis of atopic dermatitis is discussed in terms of heredity resulting in disturbance of skin barrier, deficiency of immune system. The later means the stimulation of Th2-cells resulting in hyperproduction of IgE, hypersensitivity to allergens and nonspecific stimulants, colonization by pathogenic microorganism such as Staphylococcus aureus, Malassezia furfur and so on. The imbalance of autonomous nerve system with increased production of inflammatory mediators is strongly considered in the pathogenesis of atopic dermatitis too. Conclusion. Considering the multifactoriality of atopic dermatitis the maintenance pharmacotherapy is of particular importance. (For citation: Petrova IV, Omarov NN, Sargsyan МS, et al. Maintenance pharmacotherapy of atopic dermatitis. Reviews on Clinical Pharmacology and Drug Therapy. 2018;16(1):60-63. doi: 10.17816/RCF16160-63).

Induction of Kanizsa contours requires awareness of the inducing context

It remains unknown to what extent the human visual system interprets information about complex scenes without conscious analysis. Here we used visual masking techniques to assess whether illusory contours (Kanizsa shapes) are perceived when the inducing context creating this illusion does not reach awareness. In the first experiment we tested perception directly by having participants discriminate the orientation of an illusory contour. In the second experiment, we exploited the fact that the presence of an illusory contour enhances performance on a spatial localization task. Moreover, in the latter experiment we also used a different masking method to rule out the effect of stimulus duration. Our results suggest that participants do not perceive illusory contours when they are unaware of the inducing context. This is consistent with theories of a multistage, recurrent process of perceptual integration. Our findings thus challenge some reports, including those from neurophysiological experiments in anaesthetized animals. Furthermore, we discuss the importance to test the presence of the phenomenal percept directly with appropriate methods.