Evolutionary Dynamics of Multigene Families in Triportheus (Characiformes, Triportheidae): A Transposon Mediated Mechanism?

Triportheus (Characiformes, Triportheidae) is a freshwater fish genus with 18 valid species. These fishes are widely distributed in the major river drainages of South America, having commercial importance in the fishing market, mainly in the Amazon basin. This genus has diverged recently in a complex process of speciation carried out in different river basins. The use of repetitive sequences is suitable to trace the genomic reorganizations occured along the speciation process. In this work, the 5S rDNA multigene family has been characterized at molecular and phylogenetic level. The results showed that other multigene family has been found within the non-transcribed spacer (NTS): the U1 snRNA gene. Double-FISH with 5S and U1 probes were also performed, confirming the close linkage between these two multigene families. Moreover, evidences of different transposable elements (TE) were detected within the spacer, thus suggesting a transposon-mediated mechanism of 5S-U1 evolutionary pathway in this genus. Phylogenetic analysis demonstrated a species-specific grouping, except for Triportheus pantanensis, Triportheus aff. rotundatus and Triportheus trifurcatus. The evolutionary model of the 5S rDNA in Triportheus species has been discussed. In addition, the results suggest new clues for the speciation and evolutionary trend in these species, which could be suitable to use in other Characiformes species

Avaliação da Harmonia Facial em Relação às Proporções Divinas de Fibonacci

ResumoDe acordo com alguns autores, as faces consideradas belas apresentam-se em Proporção Divina, ou seja, na relação de 1:0,618. Esta pesquisa investiga se essa proporção manifesta-se nas faces de pessoas selecionadas por avaliadores, utilizando, para tal, o critério de beleza. A amostra inicial foi composta por 104 pessoas, previamente selecionadas e separadas em grupos M (masculino) e F (feminino), sendo realizados, de cada participante, dois registros fotográficos (A e B). A partir do registro fotográfico A, obtiveram-se fotografias (frontal e lateral), que foram submetidas ao exame por um grupo de avaliadores. De posse dos valores atribuídos, foram identificados os sujeitos que comporiam a amostra final, assim constituída: subgrupos M1 e F1 (10 pessoas com valor numérico maior) e M2 e F2 (10 pessoas com valor numérico menor), totalizando uma amostra final de 80 fotografias (frontais e laterais) a partir do registro fotográfico B. Prosseguiuse com a análise facial propriamente dita. Os dados obtidos foram comparados com a Proporção Divina, observando-a em apenas duas das proporções avaliadas. Assim, pode-se afirmar que a Proporção Divina não está associada à percepção da beleza no contexto desta pesquisa.AbstractIn agreement with some researched authors the beautiful faces are in divine proportion or 1:0,618. The present study was developed with the intention of investigating if the people selected by appraisers using the criterion of facial beauty shows the divine proportion. The initial sample was obtained starting from 104 people selected previously and separate in groups M (male) and F (female) being accomplished two photographic registrations of each participant (A and B). Starting from the photographic registration A was obtained pictures (frontal and lateral) which underwent the evaluation for a group of appraisers. With the rates attributed by the appraisers was identified the subjects that would compose the final sample constituted like this: subgroups M1 and F1 (10 people with larger numeric rate) and M2 and F2 (10 people with smaller numeric rate) totaling a final sample of 80 pictures (frontal and lateral) starting from the photographic registration B. Proceeding with the facial analyses. The obtained data were compared with the divine proportion and only in two proportions happened identification with these rates. Like this would be affirmed that the divine proportion is not associated to the perception of the beauty in the context of this research

Cross-species chromosome painting tracks the independent origin of multiple sex chromosomes in two cofamiliar Erythrinidae fishes

<p>Abstract</p> <p>Background</p> <p>The Erythrinidae fish family is characterized by a large variation with respect to diploid chromosome numbers and sex-determining systems among its species, including two multiple X₁X₂Y sex systems in <it>Hoplias malabaricus </it>and <it>Erythrinus erythrinus</it>. At first, the occurrence of a same sex chromosome system within a family suggests that the sex chromosomes are correlated and originated from ancestral XY chromosomes that were either homomorphic or at an early stage of differentiation. To identify the origin and evolution of these X₁X₂Y sex chromosomes, we performed reciprocal cross-species FISH experiments with two sex-chromosome-specific probes designed from microdissected X₁and Y chromosomes of <it>H. malabaricus </it>and <it>E. erythrinus</it>, respectively.</p> <p>Results</p> <p>Our results yield valuable information regarding the origin and evolution of these sex chromosome systems. Our data indicate that these sex chromosomes evolved independently in these two closed related Erythrinidae species. Different autosomes were first converted into a poorly differentiated XY sex pair in each species, and additional chromosomal rearrangements produced both X₁X₂Y sex systems that are currently present.</p> <p>Conclusions</p> <p>Our data provide new insights into the origin and evolution of sex chromosomes, which increases our knowledge about fish sex chromosome evolution.</p

Recovery and performance in sport: Consensus statement

© 2018 Human Kinetics, Inc. The relationship between recovery and fatigue and its impact on performance has attracted the interest of sport science for many years. An adequate balance between stress (training and competition load, other life demands) and recovery is essential for athletes to achieve continuous high-level performance. Research has focused on the examination of physiological and psychological recovery strategies to compensate external and internal training and competition loads. A systematic monitoring of recovery and the subsequent implementation of recovery routines aims at maximizing performance and preventing negative developments such as underrecovery, nonfunctional overreaching, the overtraining syndrome, injuries, or illnesses. Due to the inter- and intraindividual variability of responses to training, competition, and recovery strategies, a diverse set of expertise is required to address the multifaceted phenomena of recovery, performance, and their interactions to transfer knowledge from sport science to sport practice. For this purpose, a symposium on Recovery and Performance was organized at the Technical University Munich Science and Study Center Raitenhaslach (Germany) in September 2016. Various international experts from many disciplines and research areas gathered to discuss and share their knowledge of recovery for performance enhancement in a variety of settings. The results of this meeting are outlined in this consensus statement that provides central definitions, theoretical frameworks, and practical implications as a synopsis of the current knowledge of recovery and performance. While our understanding of the complex relationship between recovery and performance has significantly increased through research, some important issues for future investigations are also elaborated

Athletic Performance and Recovery-Stress Factors in Cycling: An Ever Changing Balance

We sought to examine whether the relationship between recovery-stress factors and performance would differ at the beginning (Stage 1) and the end (Final Stage) of a multi-stage cycling competition. Sixty-seven cyclists with a mean age of 21.90 years (SD = 1.60) and extensive international experience participated in the study. The cyclists responded to the Recovery-Stress Questionnaire for Athletes (RESTQ-Sport) and rated their performance (1 = extremely poor to 10 = excellent) in respect to the first and last stage. Two step-down multiple regression models were used to estimate the relationship among recovery (nine factors; e.g., Physical Recovery, Sleep Quality) and stress factors (10 factors; e.g., Lack of Energy, Physical Complaints), as assessed by the RESTQ and in relation to performance. Model-1 pertained to Stage 1, whereas Model-2 used data from the Final Stage. The final Model-1 revealed that Physical Recovery (β = .46, p = .01), Injury (β = -.31, p = .01) and General Well-being (β = -.26, p = .04) predicted performance in Stage 1 (R2 = .21). The final Model-2 revealed a different relationship between recovery-stress factors and performance. Specifically, being a climber (β = .28, p = .01), Conflicts/Pressure (β = .33, p = .01), and Lack of Energy (β = -.37, p = .01) were associated with performance at the Final Stage (R2 = .19). Collectively, these results suggest that the relationship among recovery and stress factors changes greatly over a relatively short period of time, and dynamically influences performance in multi-stage competitions