83 research outputs found

    Resgatando a história demográfica e evolutiva dos primatas platyrrhini através de dados do sistema oxitocinérgico

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    A presente Tese apresenta um panorama sobre a história evolutiva e demografica de primatas Platyrrhini através da investigação do sistema oxitocinérgico. Primatas dessa parvorder formam um grupo monofilético que divergiram a aproximadamente 40Ma, ocupando uma diversidade de nichos ecologicos e comportamentais, apresentando uma alta taxa de comportamentos sociais complexos que não são comuns em primatas ou mamíferos em geral, como monogamia social ou cuidado paterno da prole. O presente estudo ampliou o conhecimento sobre genes do sistema oxitocinérgico (OXT, AVPR1b, AVPR2 e LNPEP) nas três famílias de primatas Platyrrhini: Cebidae, Pitheciidae e Atelide, aumentando a representativade em espécies sem informações genômicas em bancos de dados. A partir desta abordagem de análises coevolutivas e genômica comparativas podemos inferir sobre como a variabilidade do sistema nestas espécies de primatas influenciou nos diferentes padrões de comportamentos sociais encontrados. A presente Tese traz ainda manuscritos adicionais envolvendo temas relevantes como a evolução gene-cultura e outras abordagens evolutivas em co-autoria como a corrida armamentista entre patógenos e hospedeiros.This Thesis presents an overview of the evolutionary and demographic history of Platyrrhini primates through the investigation of the oxytocinergic system. Primates of this parvorder form a monophyletic group that diverged at approximately 40 Ma, occupying a diversity of ecological and behavioral niches, presenting a high rate of complex social behaviors that are not common in primates or mammals in general, such as social monogamy or paternal care of offspring. The present study expanded the knowledge about genes involved with the oxytocinergic system (OXT, AVPR1b, AVPR2 and LNPEP) in the three families of Platyrrhini primates: Cebidae, Pitheciidae and Atelide, increasing the representativeness in species without genomic information in databases. From comparative genomic and coevolutionary analyzes we can infer about how the variability of the oxytocinergic system of these primate species influenced their different patterns of social behavior. This Thesis also brings additional manuscripts involving relevant topics like gene-culture evolution and other evolutionary approaches in co-authorship such as pathogen and host arms race

    ACE2 diversity in placental mammals reveals the evolutionary strategy of SARS-CoV-2

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    The recent emergence of SARS-CoV-2 is responsible for the current pandemic of COVID-19, which uses the human membrane protein ACE2 as a gateway to host-cell infection. We performed a comparative genomic analysis of 70 ACE2 placental mammal orthologues to identify variations and contribute to the understanding of evolutionary dynamics behind this successful adaptation to infect humans. Our results reveal that 4% of the ACE2 sites are under positive selection, all located in the catalytic domain, suggesting possibly taxon-specific adaptations related to the ACE2 function, such as cardiovascular physiology. Considering all variable sites, we selected 30 of them located at the critical ACE2 binding sites to the SARS-CoV-like viruses for analysis in more detail. Our results reveal a relatively high diversity of ACE2 between placental mammal species, while showing no polymorphism within human populations, at least considering the 30 inter-species variable sites. A perfect scenario for natural selection favored this opportunistic new coronavirus in its trajectory of infecting humans. We suggest that SARS-CoV-2 became a specialist coronavirus for human hosts. Differences in the rate of infection and mortality could be related to the innate immune responses, other unknown genetic factors, as well as non-biological factors

    ACE2 diversity in placental mammals reveals the evolutionary strategy of SARS-CoV-2

    Get PDF
    The recent emergence of SARS-CoV-2 is responsible for the current pandemic of COVID-19, which uses the human membrane protein ACE2 as a gateway to the host-cell infection. We perform comparative genomic analysis of 70 ACE2 placental mammal orthologues to identify variations and contribute to the understanding of evolutionary dynamics behind this successful adaptation to infect humans. Our results reveal that 4% of the ACE2 sites are under positive selection, all located in the catalytic domain, suggesting possibly taxon-specific adaptations related to the ACE2 function, such as cardiovascular physiology. Considering all variable sites, we selected 30 of them located at the critical ACE2 binding sites to the SARS-CoV-like viruses to analyze in more detail. Our results reveal a relatively high diversity of ACE2 between placental mammal species while showing no polymorphism within human populations, at least considering the 30 inter-species variable sites. A perfect scenario for natural selection favored this opportunistic new coronavirus in its trajectory of infecting humans. We suggest that SARS-CoV-2 became a specialist coronavirus for human hosts. Differences in the rate of infection and mortality could be related to the innate immune responses, other unknown genetic factors, as well as non-biological factors

    A Docência universitária sob a ótica do pensamento complexo: Desafios de uma formação em desconstrução

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    Pautado em uma abordagem qualitativa, o presente ensaio é um estudo bibliográfico com base na filosofia de Edgar Morin em diálogo com estudos sobre a docência universitária. Pensar a formação humana em suas diferentes esferas a partir de uma estratégia de pensamento que não seja redutora nem totalizante, mas reflexiva, a qual se opõe à racionalidade técnica, é um desafio posto no campo da Educação que nos faz repensar tanto os nossos pressupostos epistemológicos, como os nossos propósitos formativos. Buscar um novo modelo de ser humano, além das ambições mercadológicas, são objetivos traçados pelo presente estudo. Assim, um novo modelo de docência universitária que conceba um profissional integral, com consciência de suas atitudes e sua condição humana no mundo, são atributos a serem discutidos e elencados para se desconstruir velhos paradigmas formativos e desenhar possíveis caminhos dentro das universidades para uma docência inovadora

    Modeling of soil water retention based on 3D micro-tomographic image analysis

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    858-863This paper proposes the use of an algorithm based on the mercury intrusion porosimetry (MIP) method to obtain the water retention characteristic curve (pF curve) of a soil under different treatments. 3D X-ray micro-tomographic images were used to quantify pore size distribution, which was employed for the evaluation of the water retention in different matric potentials. The results showed very good agreement between the traditional method (obtained by suction tables) and that one based on the MIP algorithm. It means that the use of simulation procedures can be an interesting alternative for the measurement of soil water retention properties

    Evolutionary history of the SARS-CoV-2 Gamma variant of concern (P.1): a perfect storm

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    Our goal was to describe in more detail the evolutionary history of Gamma and two derived lineages (P.1.1 and P.1.2), which are part of the arms race that SARS-CoV-2 wages with its host. A total of 4,977 sequences of the Gamma strain of SARS-CoV-2 from Brazil were analyzed. We detected 194 sites under positive selection in 12 genes/ORFs: Spike, N, M, E, ORF1a, ORF1b, ORF3, ORF6, ORF7a, ORF7b, ORF8, and ORF10. Some diagnostic sites for Gamma lacked a signature of positive selection in our study, but these were not fixed, apparently escaping the action of purifying selection. Our network analyses revealed branches leading to expanding haplotypes with sites under selection only detected when P.1.1 and P.1.2 were considered. The P.1.2 exclusive haplotype H_5 originated from a non-synonymous mutational step (H3509Y) in H_1 of ORF1a. The selected allele, 3509Y, represents an adaptive novelty involving ORF1a of P.1. Finally, we discuss how phenomena such as epistasis and antagonistic pleiotropy could limit the emergence of new alleles (and combinations thereof) in SARS-COV-2 lineages, maintaining infectivity in humans, while providing rapid response capabilities to face the arms race triggered by host immuneresponses

    Estudo anatomico do ligamento popliteo obliquo

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    OBJECTIVE:To study the anatomy of the oblique popliteal ligament, as regards its dimensions, expansion and anatomical relationships.METHODS:Eleven cadaver knees were dissected in order to study the anatomy and take mea-surements of anatomical structures and relationships of the oblique popliteal ligament. The dissection was for posterior access to the proper exposure of the oblique popliteal ligament, the semimembranosus muscle and its expansions. For measurement of dimensions, 40 × 12 needles were used for marking the specific points and a caliper. The angles were calculated using the software ImagePro Plus(r) .RESULTS:The distance from the origin of the oblique popliteal ligament to the tibial plateau was 7.4 mm, the thickness at its origin was 7.3 mm, length was 33.6 mm and the tibial plateau angle 34.8°. The length of the expansion of the proximal oblique popliteal ligament was 39.2 mm, thickness 7.8 mm and angle of the oblique popliteal ligament with its expansion 32.2°.CONCLUSION:The oblique popliteal ligament is thick, rises in the semimembranosus and protrudes proximally forming an acute angle with the joint interline, crossing the popliteal fossa. In some cases it has a proximal expansion.OBJETIVO:Estudar a anatomia do ligamento poplíteo oblíquo no que se refere às suas dimensões, expansões e relações anatômicas.MÉTODOS:Onze joelhos de cadáveres foram dissecados com o intuito de se estudar a anatomia e fazer medições das estruturas e das relações anatômicas do ligamento poplíteo oblíquo. A dissecção foi por acesso posterior até a exposição adequada do ligamento poplíteo oblíquo, do músculo semimembranoso e de suas expansões. Para aferição das medidas, foram usados agulhas 40x12 na marcação dos pontos específicos e um paquímetro. Os ângulos foram calculados com o auxílio do software ImagePro Plus(r).RESULTADOS:A distância da origem do ligamento poplíteo oblíquo ao platô tibial foi de 7,4 mm, a espessura na sua origem foi de 7,3 mm, o comprimento foi de 33,6 mm e o ângulo com o platô tibial foi de 34,8°. O comprimento da expansão proximal do ligamento poplíteo oblíquo foi de 39,2 mm, a espessura foi de 7,8 mm e o ângulo do ligamento poplíteo oblíquo com sua expansão foi de 32,2°.CONCLUSÃO:O ligamento poplíteo oblíquo é espesso, nasce no músculo semimembranoso, projeta-se proximalmente, forma um ângulo agudo com a interlinha articular e cruza a fossa poplítea. Em alguns casos apresenta uma expansão proximal.Universidade Federal do ParanaUniversidade Federal de São Paulo (UNIFESP)Universidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaPontificia Universidade Catolica do ParanaUNIFESP, EPMSciEL

    Genetic parameters for faecal egg count, packed-cell volume and body-weight in Santa Inês lambs

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    Worm infection is one of the main factors responsible for economic losses in sheep breeding in Brazil. Random regression analysis was used to estimate genetic parameters for the factors faecal egg-count (FEC), packed-cell volume (PCV) and body weight (BW) in Santa Inês lambs. Data from 119 female, offspring of nine rams, were collected between December, 2005 and December, 2006, from the experimental flock of Embrapa Tabuleiros Costeiros, the Brazilian Agricultural Research Corporation located in Frei Paulo, SE, Brazil. After weaning, females were drenched until the faecal egg count had dropped to zero. Two natural challenges were undertaken. FEC heritability was extremely variable, this increasing from 0.04 to 0.27 in the first challenge and from 0.01 to 0.52 during the second. PCV heritability peaks were 0.31 and 0.12 in the first and second challenges, respectively. In the second challenge, BW heritability was close to 0.90. The genetic correlations among these traits did not differ from zero. There is the possibility of increasing parasite resistance in Santa Inês by selecting those animals with lower FEC. Selection to increase resistance will not adversely affect lamb-growth, although lambs with a slow growth-rate may be more susceptible to infection
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