Sobre escravos e genes: “origens” e “processos” nos estudos da genética sobre a população brasileira / On slaves and genes: “origins” and “processes” in genetic studies of the Brazilian population

Neste artigo examino como geneticistas contemporâneos que pesquisam a história e a configuração da população brasileira interagem com outras disciplinas. Para tanto, tomei como estudo de caso artigos publicados por geneticistas que investigam a presença de variantes da hemoglobina S no Brasil, os quais pretendem claramente contribuir para a análise de questões como escravidão ou identidade étnica no país. Contrastando esses estudos com trabalhos contemporâneos da história e das ciências sociais, problematizo a centralidade explanatória da “origem” nos estudos genéticos analisados, bem como a falta de interação com questões epistemológicas de outras áreas do saber.

In this article I examine how contemporary geneticists investigating the history and configuration of the Brazilian population engage with other academic disciplines. To do so I use as a case study some articles published by geneticists researching the presence of hemoglobin S variants in Brazil, in which there is a clear pretension to contribute to the analysis of issues such as slavery or Brazil’s ethnic identity. By contrasting these studies with contemporary works from history and the social science, the explanatory centrality of “origin” in the genetic studies analyzed is problematized, as is the lack of interaction with the epistemological characteristics of other areas of knowledge.

Genetic characterization of Toxoplasma gondii isolates from eared doves (Zenaida auriculata) in Brazil / Caracterização genética de isolados de Toxoplasma gondii de pombos (Zenaida auriculata) no Brasil

Eared doves (Zenaida auriculata), which are common in urban, rural and wild areas in many regions of Brazil, are frequently prey for domestic cats. Therefore Toxoplasma gondii isolates obtained from doves may reflect greater environmental diversity than those from other hosts. The aim of the present study was to evaluate T. gondii seroprevalence, isolate and genotype strains from Z. auriculata. Serum and tissue samples were collected from 206 doves for use in the modified agglutination test (MAT) and mouse bioassay. The prevalence of T. gondii antibodies in the doves was 22.3% (46/206), with titers ranging from 16 to 4096, and T. gondii strains were isolated from 12 of these doves. Five genotypes were detected by means of PCR-RFLP, including ToxoDB genotypes #1, #6, #17 and #65, and one genotype that had not previously been described (ToxoDB#182). This was the first report on isolation of T. gondii from Z. auriculata. This study confirmed the genetic diversity of T. gondii isolates and the existence of clonal type II (ToxoDB genotype #1) in Brazil.

Pombos silvestres (Zenaida auriculata), comuns em áreas urbanas, rurais e selvagens em muitas regiões do Brasil, são frequentemente predados por gatos domésticos. Sendo assim, os isolados de T. gondii obtidos de pombos podem refletir uma maior diversidade ambiental do que os outros hospedeiros. O objetivo do presente estudo foi avaliar a soroprevalência, isolar e genotipar T. gondii de Z. auriculata. Amostras de soro e tecido foram coletadas de 206 pombos para o teste de aglutinação modificado (MAT) e o bioensaio em camundongos. A prevalência de anticorpos contra T. gondii em pombos foi 22,3% (46/206), com títulos variando de 16 a 4096, e T. gondii foi isolado de 12 pombos. Cinco genótipos foram detectados por PCR-RFLP, incluindo os genótipos ToxoDB #1, #6, #17, #65 e um genótipo não descrito anteriormente (ToxoDB#182). Esse é o primeiro relato de isolamento de T. gondii de Z. auriculata. Este estudo também confirmou a diversidade dos isolados de T. gondii e a presença de tipo clonal II (ToxoDB #1) no Brasil.

Exposure of free-living jaguars to Toxoplasma gondii, Neospora caninum and Sarcocystis neurona in the Brazilian Pantanal / Exposição de onças-pintadas a Toxoplasma gondii, Neospora caninum e Sarcocystis neurona no Pantanal brasileiro

Toxoplasma gondii, Neospora caninum and Sarcocystis neurona are related apicomplexan parasites that cause reproductive and neurological disorders in a wide range of domestic and wild animals. In the present study, the immunofluorescence antibody test (IFAT) was used to investigate the presence of antibodies against T. gondii, N. caninum and S. neurona in the sera of 11 free-living jaguars (Panthera onca) in two protected areas in the Pantanal region of Mato Grosso state, Brazil. Ten jaguars (90.9%) showed seropositivity for T. gondii, eight (72.7%) for S. neurona, and seven (63.6%) for N. caninum antigens. Our findings reveal exposure of jaguars to these related coccidian parasites and circulation of these pathogens in this wild ecosystem. To the best of our knowledge, this is the first serological detection of N. caninum and S. neurona in free-living jaguars.

Toxoplasma gondii, Neospora caninum e Sarcocystis neurona são coccídios relacionados responsáveis por causar desordens reprodutivas e neurológicas em uma ampla variedade de animais domésticos e selvagens. No presente estudo, a Reação de Imunofluorescência Indireta (RIFI) foi utilizada para investigar a presença de anticorpos contra T. gondii, N. caninum e S.neurona em soros de 11 onças-pintadas de vida livre (Panthera onca), provenientes de duas áreas protegidas na região do Pantanal do Estado de Mato Grosso, Brasil. Dez (90,9%), sete (63,6%) e oito (72,7%) onças amostradas foram soropositivas para T. gondii, N. caninum e S. neurona, respectivamente. Os resultados indicam a exposição a esses coccídios relacionados entre as onças-pintadas e a circulação ambiental desses patógenos nesse ecossistema selvagem. Este é o primeiro relato da detecção sorológica de N. caninum e S. neurona em onças-pintadas de vida livre.

Autonomia do graduando em enfermagem na (re)construção do conhecimento mediado pela aprendizagem baseada em problemas / Autonomy of nursing undergraduate student in the (re)construction of knowledge mediated by problem-based learning / La autonomía del estudiante de enfermería en la (re)construcción del conocimiento mediada por el aprendizaje basado en problemas

Estudo qualitativo, método Bricolagem, que objetivou analisar como a Aprendizagem Baseada em Problemas (ABP) promove o desenvolvimento da autonomia do aluno no processo de aprender a aprender. Os sujeitos foram 16 alunos e dois tutores envolvidos na disciplina. A coleta dos dados combinou entrevista semiestruturada, observação participante, registro em portfólios, fichas de avaliação, e gravação em áudio das tutorias. A análise dos dados seguiu estratégias de interpretação definidas pelas autoras: leituras iniciais e aprofundada; construção e reunião de mapas de significados; elaboração, descrição e análise de categorias empíricas, à luz do referencial teórico. A ABP favorece a (re)construção de conhecimentos pela utilização de saberes e experiências prévias, que são compartilhados no pequeno grupo; pelo processo de teorização; e pela via do conhecimento pertinente - aquele passível de aplicação à prática. Concluímos que a ABP estimula o aprendizado contínuo, desenvolvendo no aluno autonomia no processo de aprender a aprender.

This is a qualitative study, using the ‘Do it yourself’ method, which aimed to analyze how Problem-Based Learning (PBL) promotes the development of learner’s autonomy in the process of learning to learn. The subjects were 16 students and two tutors involved in the discipline. Data collection techniques combined semi-structured interviews, participant observation, log in portfolios, evaluation forms, and audio recording of the tutorials. Data analysis followed interpretation strategies defined by the authors: initial and in depth readings; construction and assembly of meanings’ maps; development, description and analysis of empirical categories, in the light of the theoretical framework. The PBL favors the (re)construction of knowledge by the use of prior knowledge and experiences that are shared in small group; through the process of theorization; and by means of relevant knowledge - one that can be applied to practice. We conclude that PBL encourages continuous learning, developing in the student the autonomy in the process of learning to learn.

Estudio cualitativo, con método Bricolage, que tuvo como objetivo analizar cómo el Aprendizaje Basado en Problemas (ABP) promueve el desarrollo de la autonomía del alumno en el proceso de aprender a aprender. Los sujetos fueron 16 alumnos y dos tutores que participan en la disciplina. Para recolección de datos se combinaran entrevistas estructuradas, observación participante, registro en portfolios, formularios de evaluación y grabación de audio de los tutoriales. El análisis de los datos siguió las estrategias de interpretación definidos por los autores: lecturas iniciales y profundadas; construcción y montaje de mapas de significados; el desarrollo, descripción y análisis de categorías empíricas, a la luz de lo referencial teórico. El ABP favorece la construcción de conocimientos mediante el uso de saberes y experiencias que se comparten en grupos pequeños, a través del proceso de teorización, y por medio de los conocimientos pertinentes - uno que se puede aplicar a la práctica. Llegamos a la conclusión que el ABP promueve el aprendizaje continuo, el desarrollo de los estudiantes, la autonomía en el proceso de aprender a aprender.

Handling of ferric iron by branchial and intestinal epithelia of climbing perch (Anabas testudineus Bloch).

With a view to test how the branchial and intestinal tissues of fish, the two sites of metal acquisition, utilize the water-borne ferric [Fe(III)] iron and whether the accumulation of this form of iron influences cellular Na/K gradient in these tissues, the gills and intestines of climbing perch adapted to freshwater (FW) and acclimated to dilute seawater (20 ppt; SW) were analyzed for ouabain-sensitive Na+, K+-ATPase activity, Fe and electrolyte contents after loading a low (8.95 microM) or high dose (89.5 microM) of Fe(III) iron in the water. The SW gills showed higher levels of total Fe after treating with 8.95 microM of Fe(III) iron which was not seen in the FW gills. Na+, K+-ATPase activity, reflecting Na/K pump activity, showed an increase in the FW gills and not in the SW gills. Substantial increase in the branchial Na and K content was observed in the SW gills, but the FW gills failed to show such effects after Fe(III) loading. The total Fe content was declined in the FW intestine but not in the SW intestine. Water-borne Fe(III) iron decreased the activity of Na+, K+-ATPase in the SW intestine while not changing its activity in the FW intestine. The Na and K content in the FW intestine did not respond to Fe(III) iron exposure but showed a reduction in its Na levels in the SW intestine. The moisture content in the gills and intestines of both the FW and SW perch remained unaffected after Fe(III) loading. In FW fish, the plasma Na levels were decreased by a low dose of Fe(III) iron, though a high dose of Fe(III) iron was required in the SW fish for such an effect. Overall, the results for the first time provide evidence that gills act as a major site for Fe(III) iron absorption and accumulation during salinity acclimation which depends on a high cellular Na/K gradient.

Use of PEI-coated magnetic iron oxide nanoparticles as gene vectors / 华中科技大学学报（医学）（英德文版）

To evaluate the feasibility of using polyethyleneimine (PEI) coated magnetic iron.oxide nanoparticles (polyMAG-1000) as gene vectors. The surface characteristics of the nanoparticles were observed with scanning electron microscopy. The ability of the nanoparticles to combine with and protect DNA was investigated at different PH values after polyMAG-1000 and DNA were combined in different ratios. The nanoparticles were tested as gene vectors with in vitro transfection models. Under the scanning electron microscope the nanoparticles were about 100 nm in diameter. The nanoparticles could bind and condense DNA under acid, neutral and alkaline conditions, and they could transfer genes into cells and express green fluorescent proteins (GFP). The transfection efficiency was highest (51%) when the ratio of nanoparticles to DNA was 1:1 (v:w). In that ratio, the difference in transfection efficiency was marked depending on whether a magnetic field was present or not: about 10% when it was absent but 51% when it was present. The magnetic iron oxide nanoparticles coated with PEI may potentially be used as gene vectors.