Parasitism by Amblyomma rotundatum on Teiidae lizards in the eastern part of the state of Acre, Brazil.

The aim of the present study was to report on the occurrence of parasitism by Amblyomma rotundatum ticks on two species of Teiidae lizards and test the presence of rickettsiae in the collected ticks, in the western Brazilian Amazon region. Ticks were collected in July 2019, from a fragment of terra firme forest in the municipality of Senador Guiomard, Acre, Brazil. Two lizards that were infested by immature stages of ticks were caught using mist net and Tomahawk traps. Ectoparasites were collected manually, and the lizard specimens were identified and released at the same location where they had been caught. Three nymphs and 49 larvae were collected from Ameiva ameiva, while 25 nymphs and nine larvae were collected from Tupinambis cuzcoensis, which are both in the family Teiidae. The ticks were identified morphologically as belonging to the genus Amblyomma. Nymphs were identified at species level through molecular analysis, resulting in the tick species Amblyomma rotundatum. This is the first record of parasitism by the tick A. rotundatum on T. cuzcoensis lizard, and the first report of an association between A. rotundatum and the lizard species A. ameiva and T. cuzcoensis in Acre, in the western part of the Amazon region.

Detection of Rickettsia tamurae-like and other spotted fever group rickettsiae in ticks (Acari: Ixodidae) associated with wild birds in the Western Amazon, Brazil.

Ticks are vectors for several pathogens, including bacteria belonging to the Rickettsia genus, such as Rickettsia rickettsii and Rickettsia parkeri, the causative agents of spotted fever. The aim of the present study was to investigate the tick species richness and rickettsial agents associated with wild birds captured in the Humaita Forest Reserve, Acre, in the Western Amazon region. Wild birds were captured with ornithological nets for visual inspection with the purpose of collecting ticks, which were identified through morphological analyses and molecular tests for several genes (12S rDNA, 16S rDNA, gltA, ompA, and sca4). A total of 607 wild birds were captured, 12% of which were parasitized by 268 ticks of the Amblyomma genus, with new host-parasite associations reported for Amblyomma calcaratum, Amblyomma geayi, Amblyomma longirostre, Amblyomma naponense, Amblyomma nodosum, and Amblyomma varium. Of the total ticks collected, 113 were tested for the presence of rickettsial DNA fragments, with 19 testing positive for R. parkeri in A. geayi, Rickettsia tamurae-like in Amblyomma sp., and Rickettsia amblyommatis in A. geayi, A. longirostre, and Amblyomma sp. We detected R. tamurae-like in Amblyomma larvae for the first time in the Western Brazilian Amazon biome, and registered spotted fever group rickettsiae, although the relevance of the detected species in a public health context should be further explored in South America, as well as new host-parasite interactions in this underexplored region.

Interaction models between peptide substrate and Alphavirus Protease nsP2 of Chikungunya and Mayaro and implications to the mechanism of action.

The Arbovirus (Arthropod-borne virus) is a group which comprises viruses whose transmission is carried out by arthropod vectors infecting vertebrates. Some arboviruses related to human diseases have been given considerable relevance as Chikungunya and Mayaro of the family Togaviridae, genus Alphavirus. The lack of proper specific treatment has prompted the requirement for deeper structural studies that could unveil leads to new drugs. Among possible targets, viral proteases are recognized as proteins with big potential. These proteins, termed nsP2 in Alphavirus, have the function of cleaving certain regions of the viral polyprotein, being vital to the viral cycle. In this research, we used docking and molecular dynamics to analyze the contact between the protease nsP2 of Alphavirus Chikungunya and Mayaro and substrates formed by peptides with ten amino acid residues. A model of the Mayaro nsP2 was constructed based on homologous proteases. Our study suggests that the glycine specificity motif, a region where a highly conserved glycine residue in position P2 of the protease substrate is positioned, facilitates the nucleophilic attack by assisting in placing the P1 carbonyl group carbon. Stabilization of different substrate regions maybe explained by relevant contacts with the enzyme. Besides that, the phi and psi angles in the outlier region of the Ramachandran plot found for the P2 glycine of the Chikungunya substrate seems to indicate the necessity of this residue that can accommodate angles not allowed to other residues.Communicated by Ramaswamy H. Sarma.

Breeding records of Leptotila rufaxilla (Aves: Columbidae) in southwestern Brazilian Amazon with notes on nesting in some regions of occurrence

We present new aspects of breeding biology of Gray-fronted Dove Leptotila rufaxilla, from five nests found between 2012 and 2014 in a lowland forest fragment in southwestern Brazil. The nests simple/platform shape were built at a mean height of 1.90 m above ground. The clutch size was two eggs white and elliptic, incubated for 15 days (based on three nests). We recorded predation in two nests still in incubation phase. Minimum hatch weight of nestlings was 10 g and young fledged with a mean mass of 56 g. The constant growth rate (K) of nestlings was 0.40 with a growth asymptote of 60.7 g. Daily survival rate, Mayfield and apparent nesting success in the incubation period was 90, 20 and 56%, respectively, while in the nestling period were all 100%. Our data and the contribution of citizen science showed that L. rufaxilla breeds over the year, mainly in the rainy season, both in southwestern Amazonia and in other regions of occurrence.

Presentamos nuevos aspectos de la biología reproductiva de la Yerutí Colorada Leptotila rufaxilla, de cinco nidos encontrados entre 2012 y 2014 en un fragmento de bosque de tierras bajas en el suroeste de Brasil. Los nidos con forma simple / plataforma se construyeron a una altura media de 1.90 m sobre el suelo. El tamaño de la puesta fue de dos huevos blancos y elípticos, incubados durante 15 días (basado en tres nidos). Registramos depredación en dos nidos aún en fase de incubación. El peso mínimo al nacer de los pichones fue de 10 g y los polluelos dejaron el nido con una masa media de 56 g. La tasa de crecimiento constante (K) de los pichones fue de 0.40 con una asíntota de crecimiento de 60.7 g. La tasa de supervivencia diaria, Mayfield y el éxito aparente de anidación en el período de incubación fue de 90, 20 y 56%, respectivamente, mientras que en el período de cría fueron todos de 100%. Nuestros datos y el aporte de la ciencia ciudadana mostraron que L. rufaxilla se reproduce durante el año, principalmente en la época de lluvias, tanto en el suroeste de la Amazonia como en otras regiones de ocurrencia.

Breeding biology and biometrics of Myiozetetes c. cayanensis (Aves: Tyrannidae) in southwest Brazilian Amazonia with breeding season in Brazil

Our study provides information on the breeding and biometrics of Rusty-Margined Flycatcher Myiozetetes cayanensis in southwest Brazilian Amazonia. M. cayanensis is distributed from Central America until north of South America. We made observations on reproduction and captures of this species in a terra firme forest fragment in the state of Acre, between 1999 and 2020 and we evaluated the breeding season in Brazil through citizen science data. We monitored nine nests between 2012 and 2020, built at a mean height of 1.8 m above ground. Clutch size was two, three or four eggs, incubated for 15 days. We monitored the development of six nestlings: minimum hatch weight was 2 g and young fledged with a mean mass of ca. 25.5 g. The constant growth rate (K) of nestlings was 0.18 with a growth asymptote of 22.8 g. Daily survival rate was 90% and 100% during the incubation and nestling periods, respectively. The Mayfield success in the incubation and nestling periods was 20 and 100%, respectively. Apparent nesting success in the incubation and nestling periods was 46 and 100%, respectively. We recorded a minimum longevity of 2 years, nine months and 26 days. The subspecies M. c. cayanensis start to nest mainly between the dry and rainy season in Brazil, overlapping with the molt period in southwest Amazonia.

Nuestro estudio proporciona información sobre la reproducción y la biometría del bienteveo alicastaño Myiozetetes cayanensis en el suroeste de la Amazonia brasileña. M. cayanensis se distribuye desde América Central hasta el norte de América del Sur. Realizamos observaciones sobre la reproducción y captura de esta especie en un fragmento de bosque de tierra firme en el estado de Acre, entre 1999 y 2020 y evaluamos la época de reproducción en Brasil mediante datos de ciencia ciudadana. Monitoreamos nueve nidos entre 2012 y 2020, construidos a una altura promedio de 1.8 m sobre el suelo. El tamaño de la puesta fue de dos, tres o cuatro huevos, incubados durante 15 días. Monitoreamos el desarrollo de seis polluelos: el peso mínimo al nacer fue de 2 g y los polluelos con una masa media de ca. 25.5 g. La tasa de crecimiento constante (K) de los polluelos fue de 0.18 con una asíntota de crecimiento de 22.8 g. La tasa de supervivencia diaria fue del 90% y 100% durante los períodos de incubación y cría, respectivamente. El éxito de Mayfield en los períodos de incubación y cría fue de 20 y 100%, respectivamente. El éxito aparente de anidación en los períodos de incubación y polluelo fue de 46 y 100%, respectivamente. Registramos una longevidad mínima de 2 años, nueve meses y 26 días. La subespecie M. c. cayanensis comienzan a anidar principalmente entre la estación seca y lluviosa en Brasil, superponiéndose con el período de muda en el suroeste de la Amazonia.

First nest records, nestling growth and morphometrics of Dendroplex picus peruvianus (Aves: Dendrocolaptidae) in southwestern Brazilian Amazon

We reported the first data on the breeding and growth in Dendroplex picus peru-vianus from a forest fragment in southwestern Amazonia. We observed and netted this species between 1999 and 2019. We found two active nests in 2012 and 2013, but we monitored only one. Clutch size was two eggs, incubated for 16 days. Theconstant growth rate (K) of nestlings was 0.31 with a growth asymptote of 46.3 g. We recorded a longest minimum longevity of eight years. Our records showed that D. p. peruvianus breeds mainly in the rainy season (September-March) overlapping with the molt period.

Reportamos los primeros datos sobre la anidación y desarrollo de Dendroplex picus peruvianus en un fragmento de bosque en el suroeste de la Amazonia. Observamos y capturamos esta especie entre 1999 y 2019. Encontramos dos nidos activos en 2012 y 2013, pero monitoreamos solo uno. El tamaño de la camada fue de dos huevos incubados durante 16 días. La tasa de crecimiento constante (K) de los polluelos fue de 0.31 con una asíntota de crecimiento de 46.3 g. Registramos una longevidad mínima de ocho años. Nuestros datos mostraron que D. p. peruvianus se reproduce principalmente en la temporada de lluvias (septiembre-marzo) superponiéndose con el periodo de cambio de pluma.

Aceitação entre estudantes do ensino básico do desenho animado O X na Xistose para construção de conhecimentos sobre esquistossomose / Acceptance of the cartoon O X na Xistose for the knowledge construction about schistosomiasis among middle school students / Aceptación entre estudiantes del ciclo básico de lo dibujo animado O X na Xistose para el desarrollo del conocimiento sobre la esquistosomiasis

O trabalho dos educadores pode ser enriquecido com o uso de recursos pedagógicos importantes no processo de ensino e aprendizagem. Considerando este aspecto, uma animação baseada no livro O feitiço da lagoa, de Virginia Schall, que trata do tema esquistossomose foi construída para estimular o conhecimento sobre a doença entre escolares e exibida para alunos do ensino básico em quatro municípios endêmicos: Jaboticatubas, Malacacheta e Santa Luzia, em Minas Gerais; e João Pessoa, na Paraíba. Após sua exibição, um questionário foi aplicado com a finalidade de verificar a aceitação e o entendimento do material. De acordo com as respostas, o desenho animado apresentou boa aceitação. Todos identificaram a esquistossomose como a doença retratada e o caramujo como o transmissor do esquistossomo. Os resultados apontaram que o desenho pode ser um importante recurso pedagógico no processo educativo, auxiliando os programas de controle da endemia, especialmente quando desenvolvidos no espaço escolar.

The educators' work can be enriched with the use of pedagogical resources which are important in the teaching and learning process. With this aspect in mind, a cartoon with the theme schistosomiasis was created, so as to promote knowledge about the disease among middle school students, and exhibited in four endemic municipalities - Jaboticatubas, Malacacheta and Santa Luzia in the state of Minas Gerais; and João Pessoa in the state of Paraíba. The animation was based on the book O feitiço da lagoa by Virginia Schall and it was shown to students in those four towns. A questionnaire was answered by them after the respective exhibitions in order to verify the acceptance and understanding of the material that was shown. According to the responses, the cartoon presented good acceptance. Everyone identified schistosomiasis as the disease displayed, and the snail that transmits the schistosome. The results showed that the cartoon can be an important pedagogical resource in the educational process, helping endemic control programs, especially when these programs are developed in the school environment.

El trabajo de los educadores puede ser enriquecido con el uso de recursos pedagógicos importantes en el proceso de enseñanza y aprendizaje. Considerando este aspecto, un dibujo animado sobre el tema esquistosomiasis fue realizado para estimular el conocimiento, entre estudiantes del ciclo básico, acerca de la enfermedad y exhibido en cuatro municipios endémicos: Jaboticatubas, Malacacheta y Santa Luzia en Minas Gerais; y João Pessoa en Paraíba. La animación fue basada en el libro O feitiço da lagoa de Virginia Schall y fue mostrada a alumnos en las cuatro localidades. Un cuestionario fue aplicado, después de cada proyección, con la finalidad de verificar la aceptación y el entendimiento del material exhibido. De acuerdo con las respuestas, el dibujo tuvo buena aceptación. Todos identificaron la esquistosomiasis como la enfermedad retratada y el caracol como el transmisor del esquistosoma. Los resultados indicaran que el dibujo animado puede ser un importante recurso pedagógico en el proceso educativo, auxiliando a los programas de control de la endemia, especialmente cuando desarrollados en el espacio escolar.

Aves associadas a clareiras naturais em uma floresta de terras baixas no sudoeste da Amazônia brasileira / Birds associated with treefall gaps in a lowland forest in southwestern Brazilian Amazonia

As comunidades naturais são sistemas dinâmicos no tempo e no espaço. A distribuição espacial de plantas e animais coincide com a disponibilidade dos recursos necessários para a sobrevivência e reprodução de cada espécie. Clareiras naturais oferecem vários recursos que influenciam a distribuição de aves na floresta. Comparamos a assembleia de aves de sub-bosque de clareiras naturais (15 clareiras) com a encontrada na floresta adjacente (15 pontos) na Reserva Florestal Humaitá, no sudoeste da Amazônia brasileira. Amostramos aves com redes de neblina e contabilizamos 700 capturas de 105 espécies. A riqueza de espécies, o número de indivíduos e a composição de espécies foram semelhantes entre clareiras e floresta, mas seis espécies foram mais associadas com as clareiras e nove com a floresta. Os nectarívoros preferiram significativamente clareiras à floresta, enquanto os insetívoros e frugívoros se distribuíram igualmente entre clareiras e floresta. A altura e a densidade da vegetação variaram significativamente entre clareiras e floresta e influenciaram a distribuição das espécies nos dois ambientes. A disponibilidade de frutos foi correlacionada positivamente com a abundância de frugívoros nas clareiras. Em geral, 33,3% das aves associadas às clareiras são espécies de sub-dossel e as demais de sub-bosque. Mostramos que o uso de clareiras pelas aves em uma paisagem fragmentada da Amazônia contribui para a heterogeneidade ambiental e a dinâmica de sucessão após eventos naturais de perturbação do habitat. (AU)

Self-homodimerization of an actinoporin by disulfide bridging reveals implications for their structure and pore formation.

The Trp111 to Cys mutant of sticholysin I, an actinoporin from Stichodactyla helianthus sea anemone, forms a homodimer via a disulfide bridge. The purified dimer is 193 times less hemolytic than the monomer. Ultracentrifugation, dynamic light scattering and size-exclusion chromatography demonstrate that monomers and dimers are the only independent oligomeric states encountered. Indeed, circular dichroism and fluorescence spectroscopies showed that Trp/Tyr residues participate in homodimerization and that the dimer is less thermostable than the monomer. A homodimer three-dimensional model was constructed and indicates that Trp147/Tyr137 are at the homodimer interface. Spectroscopy results validated the 3D-model and assigned 85° to the disulfide bridge dihedral angle responsible for dimerization. The homodimer model suggests that alterations in the membrane/carbohydrate-binding sites in one of the monomers, as result of dimerization, could explain the decrease in the homodimer ability to form pores.