Acute effect of high‑definition and conventional tDCS on exercise performance and psychophysiological responses in endurance athletes: a randomized controlled trial

Transcranial direct current stimulation (tDCS) has been used aiming to boost exercise performance and inconsistent findings have been reported. One possible explanation is related to the limitations of the so-called “conventional” tDCS, which uses large rectangular electrodes, resulting in a diffuse electric field. A new tDCS technique called high-definition tDCS (HD-tDCS) has been recently developed. HD-tDCS uses small ring electrodes and produces improved focality and greater magnitude of its aftereffects. This study tested whether HD-tDCS would improve exercise performance to a greater extent than conventional tDCS. Twelve endurance athletes (29.4 ± 7.3 years; 60.15 ± 5.09 ml kg− 1 min− 1) were enrolled in this single-center, randomized, crossover, and sham-controlled trial. To test reliability, participants performed two time to exhaustion (TTE) tests (control conditions) on a cycle simulator with 80% of peak power until volitional exhaustion. Next, they randomly received HD-tDCS (2.4 mA), conventional (2.0 mA), or active sham tDCS (2.0 mA) over the motor cortex for 20-min before performing the TTE test. TTE, heart rate (HR), associative thoughts, peripheral (lower limbs), and whole-body ratings of perceived exertion (RPE) were recorded every minute. Outcome measures were reliable. There was no difference in TTE between HD-tDCS (853.1 ± 288.6 s), simulated conventional (827.8 ± 278.7 s), sham (794.3 ± 271.2 s), or control conditions (TTE1 = 751.1 ± 261.6 s or TTE2 = 770.8 ± 250.6 s) [ F(1.95; 21.4) = 1.537; P = 0.24; η2p = 0.123]. There was no effect on peripheral or whole-body RPE and associative thoughts (P \u3e 0.05). No serious adverse effect was reported. A single session of neither HD-tDCS nor conventional tDCS changed exercise performance and psychophysiological responses in athletes, suggesting that a ceiling effect may exist

A cellular defense memory imprinted by early life toxic stress

Stress exposure early in life is implicated in various behavioural and somatic diseases. Experiences during the critical perinatal period form permanent, imprinted memories promoting adult survival. Although imprinting is widely recognized to dictate behaviour, whether it actuates specific transcriptional responses at the cellular level is unknown. Here we report that in response to early life stresses, Caenorhabditis elegans nematodes form an imprinted cellular defense memory. We show that exposing newly-born worms to toxic antimycin A and paraquat, respectively, stimulates the expression of toxin-specific cytoprotective reporters. Toxin exposure also induces avoidance of the toxin-containing bacterial lawn. In contrast, adult worms do not exhibit aversive behaviour towards stress-associated bacterial sensory cues. However, the mere re-encounter with the same cues reactivates the previously induced cytoprotective reporters. Learned adult defenses require memory formation during the L1 larval stage and do not appear to confer increased protection against the toxin. Thus, exposure of C. elegans to toxic stresses in the critical period elicits adaptive behavioural and cytoprotective responses, which do not form imprinted aversive behaviour, but imprint a cytoprotective memory. Our findings identify a novel form of imprinting and suggest that imprinted molecular defenses might underlie various pathophysiological alterations related to early life stress. © 2019, The Author(s)

Comparative genomics of proteins involved in RNA nucleocytoplasmic export

Background: The establishment of the nuclear membrane resulted in the physical separation of transcription and translation, and presented early eukaryotes with a formidable challenge: how to shuttle RNA from the nucleus to the locus of protein synthesis. In prokaryotes, mRNA is translated as it is being synthesized, whereas in eukaryotes mRNA is synthesized and processed in the nucleus, and it is then exported to the cytoplasm. In metazoa and fungi, the different RNA species are exported from the nucleus by specialized pathways. For example, tRNA is exported by exportin-t in a RanGTP-dependent fashion. By contrast, mRNAs are associated to ribonucleoproteins (RNPs) and exported by an essential shuttling complex (TAP-p15 in human, Mex67-mtr2 in yeast) that transports them through the nuclear pore. The different RNA export pathways appear to be well conserved among members of Opisthokonta, the eukaryotic supergroup that includes Fungi and Metazoa. However, it is not known whether RNA export in the other eukaryotic supergroups follows the same export routes as in opisthokonts. Methods: Our objective was to reconstruct the evolutionary history of the different RNA export pathways across eukaryotes. To do so, we screened an array of eukaryotic genomes for the presence of homologs of the proteins involved in RNA export in Metazoa and Fungi, using human and yeast proteins as queries. Results: Our genomic comparisons indicate that the basic components of the RanGTP-dependent RNA pathways are conserved across eukaryotes, and thus we infer that these are traceable to the last eukaryotic common ancestor (LECA). On the other hand, several of the proteins involved in RanGTP-independent mRNA export pathways are less conserved, which would suggest that they represent innovations that appeared later in the evolution of eukaryotes. Conclusions: Our analyses suggest that the LECA possessed the basic components of the different RNA export mechanisms found today in opisthokonts, and that these mechanisms became more specialized throughout eukaryotic evolution

Ontology Mapping Validation: Dealing With An Np-complete Problem

The use of ontologies and ontology mappings is increasing in companies. Often the s me context is modeled in different ontologies. Mapping is necessary to integrate these ontologies; however, in many cases these mappings are incorrect, i.e., they incorrectly link semantic concepts with different meanings. Tools that validate these mappings are necessary to ensure reliable communication between heterogeneous systems. This validation cannot be done in a completely automatic way, because the mappings are based on human interpretation. This work describes a semi-automatic tool that supports this activity, based on graphs that generate instances validated in a semi-automatic process that aims to ensure mapping robustness. This algorithm deals with an NP-Complete problem in order to generate all the instances. This paper presents a first prototype of the tool and the methodology used to validate the instances automatically generated by the tool. © 2011, IGI Global.33111Babic, D., Hu, A.H., Calysto: Scalable and precise extended static checking (2008) Proceedings of the 30th International Conference on Software Engineering, pp. 211-220Beizer, B., (1990) Software Testing Techniques, , (1st ed.). London, UK: International Thomson Computer PressBerg, T., Raffelt, H., Model checking (2005) Proceedings of the Advanced Lectures on Model-Based Testing of Reactive Systems (LNCS 3472), pp. 557-603. , M. Broy, B. Jonsson, J.-P. Katoen, M. Leucker, & A. Pretschner (Eds.)Bertolino, A., Software testing research: Achievements, challenges, dreams (2007) FoSE 2007: Future of Software Engineering, pp. 85-103. , DOI 10.1109/FOSE.2007.25, 4221614, FoSE 2007: Future of Software EngineeringBoccaletti, S., Latora, V., Moreno, Y., Chavez, M., Hwang, D.-U., Complex networks: Structure and dynamics (2006) Physics Reports, 424 (4-5), pp. 175-308. , DOI 10.1016/j.physrep.2005.10.009, PII S037015730500462XCardoso, J., The semantic web vision: Where are we? (2007) IEEE Intelligent Systems, 22 (5), pp. 84-88. , DOI 10.1109/MIS.2007.4338499Ehrig, M., Sure, Y., Ontology mapping - An integrated approach (2004) Proceedings of the First European Semantic Web Symposium: Research and Applications (LNCS 3053), pp. 76-91. , C. J. Bussler, J. Davies, D. Fensel, & R. Studer (Eds.)Euzenat, J., First results of the ontology alignment evaluation initiative (2010) Proceedings of the Workshop on Ontology MatchingFraser, G., Wotawa, F., Ammann, P.E., Testing with model checkers: A survey (2007) Software Testing, Verification and Reliability, 19, p. 3Jacob, E.K., Ontologies and semantic web (2003) Bulletin of the American Society for Information Science and TechnologyKalfoglou, Y., Schorlemmer, M., Ontology mapping: The state of the art (2003) Knowledge Engineering Review Journal, 18, pp. 1-31. , doi:10.1017/S0269888903000651Kropp, N.P., Koopman, P.J., Siewiorek, D.P., Automated robustness testing of off-the-shelf software components (1998) Proceedings of the 28th Annual International Symposium on Fault Tolerant Computing Symposium, , Munich, GermanyMyers, G., (1979) The Art of Software Testing, , New York, NY: John Wiley SonsPerez, I.R.D.C., Martins, E., Automação em projeto de testes usando modelos UML (2007) Proceedings of the 1st Brazilian Workshop on Systematic and Automated Software Testing, junto ao XXI Simpósio de Engenharia de SoftwareSerpeloni, F., Moraes, R., Bonacin, R., A semi-automated approach to validate ontology mappings (2010) Proceedings of the 10th Annual International Conference on New Technologies of Distributed System

Grandmaternal stress during pregnancy and DNA methylation of the third generation: an epigenome-wide association study

Stress during pregnancy may impact subsequent generations, which is demonstrated by an increased susceptibility to childhood and adulthood health problems in the children and grandchildren. Although the importance of the prenatal environment is well reported with regards to future physical and emotional outcomes, little is known about the molecular mechanisms that mediate the long-term consequences of early stress across generations. Recent studies have identified DNA methylation as a possible mediator of the impact of prenatal stress in the offspring. Whether psychosocial stress during pregnancy also affects DNA methylation of the grandchildren is still not known. In the present study we examined the multigenerational hypothesis, that is, grandmaternal exposure to psychosocial stress during pregnancy affecting DNA methylation of the grandchildren. We determined the genome-wide DNA methylation profile in 121 children (65 females and 56 males) and tested for associations with exposure to grandmaternal interpersonal violence during pregnancy. We observed methylation variations of five CpG sites significantly (FDR amp;lt; 0.05) associated with the grandmothers report of exposure to violence while pregnant with the mothers of the children. The results revealed differential methylation of genes previously shown to be involved in circulatory system processes (FDRo0.05). This study provides support for DNA methylation as a biological mechanism involved in the transmission of stress across generations and motivates further investigations to examine prenatal-dependent DNA methylation as a potential biomarker for health problems.Funding Agencies|European Research Council (ERC) through ERC advanced grant [323977]; CAPES/DAAD [18354/12-2]</p

Evaluation of Antigenotoxic Effects of Plant Flavonoids Quercetin and Rutin on HepG2 Cells

The flavonoid quercetin and its derivative rutin were investigated for genotoxicity/antigenotoxicity activity in human hepatoma HepG2 cells using the comet assay. The extract cytotoxicity was evaluated using the trypan blue exclusion dye method with quercetin and rutin concentrations ranging from 0.1 to 200.0 mu g/mL of culture medium. Three minor non-cytotoxic concentrations were chosen to evaluate the genotoxicity and antigenotoxicity of the flavonoids (0.1, 1.0 and 5.0 mu g/mL) through comet assay. The cultures were treated with three different concentrations of rutin or quercetin (genotoxicity) or their association with Aflatoxin B1 (AFB1), methyl methanesulfonate (MMS) or doxorubicin (DXR) (antigenotoxicity test) in three protocols: pretreatment, simultaneous treatment and post-treatment. The cell cultures were also treated with 1% DMSO (control group), AFB1, MMS and DXR (positive-control). Statistical analyses were performed using ANOVA and Dunnett`s test (p <= 0.05). Quercetin at concentrations higher than 10.0 mu g/mL or rutin higher than 50.0 mu g/mL exhibited a cytotoxic effect on the cells, showing that quercetin is more cytotoxic than rutin. Furthermore, neither compound was able to induce genotoxicity in the concentrations evaluated. On the other hand, both flavonoids reduced DNA damage induced by AFB1, MMS and DXR in all treatment protocols. Copyright (C) 2011 John Wiley & Sons, Ltd.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Conselho Nacional para o Desenvolvimento Cientifico e Tecnologico (CNPq)Coordenacao de Aperfeicoamento de Pessoal de Ensino Superior (CAPES/DS