--- title: "5th International Conference on Biological Physics • CBPF Index" description: "O CBPF INDEX é o sistema de acompanhamento da produção científica e tecnológica do CBPF. Nele é possível obter a lista de publicações de artigos, livros, relatórios técnicos, etc de toda a comunidade do CBPF." canonical_url: "https://index.cbpf.br/eventos/6ad2a76c639f62b11adbdc3b" locale: pt meta: "og:description": "O CBPF INDEX é o sistema de acompanhamento da produção científica e tecnológica do CBPF. Nele é possível obter a lista de publicações de artigos, livros, relatórios técnicos, etc de toda a comunidade do CBPF." "og:image": "https://index.cbpf.br/_og/d/c_Item%2Ctitulo_5th%2BInternational%2BConference%2Bon%2BBiological%2BPhysics%2Ctipo_Congresso%2Ccor_~I2Q3MDAxNQ%2Cautores_D.%2BM.%2BS.%2BEsquivel%2Cdetalhe_2004%2Csecao_Eventos%2Cp_Ii9ldmVudG9zLzZhZDJhNzZjNjM5ZjYyYjExYWRiZGMzYiI%2Cs_aV-XSSWWLa49JFQ_.png" "og:image:height": "600" "og:image:type": image/png "og:image:width": "1200" "og:title": "5th International Conference on Biological Physics • CBPF Index" "twitter:image": "https://index.cbpf.br/_og/d/c_Item%2Ctitulo_5th%2BInternational%2BConference%2Bon%2BBiological%2BPhysics%2Ctipo_Congresso%2Ccor_~I2Q3MDAxNQ%2Cautores_D.%2BM.%2BS.%2BEsquivel%2Cdetalhe_2004%2Csecao_Eventos%2Cp_Ii9ldmVudG9zLzZhZDJhNzZjNjM5ZjYyYjExYWRiZGMzYiI%2Cs_aV-XSSWWLa49JFQ_.png" --- > Index of every page on this site: [llms.txt](https://index.cbpf.br/llms.txt) **Congresso** # **5th International Conference on Biological Physics** **D. M. S. Esquivel** 2004 ## **Resumo** A magnetic resonance study of the Neocapritermes opacus termites E. Wajnberga#, J.F. de Oliveiraa, D.M.S. Esquivela, P. S. Oliveirab and O. C. Alvesc, The Neocapritermes opacus termite (N.o.) is the only prey of the migratory ant Pachycondyla marginata (P.m.). The ant migration is significantly oriented at an angle of 13o relative to the magnetic North-South axis \[1]. The geomagnetic field is a possible cue to yield this migratory information based on the magnetic iron oxides found in this ant \[2]. More recently room temperature hysteresis curves were obtained for both N.o. and P.m.\[3] showing that the magnetization saturation and coercive field are higher for the termite than for the ant. The magnetic parameters fall in the range of magnetite pseudo single or multi-domain particle values. Three heads and one oriented body (abdomen + thorax) of worker termites were cooled in a 3.4 kOe magnetic field to study orientation effects by Magnetic Resonance (MR) with the magnetic field parallel (N.o.//) and perpendicular (N.o.^) to the long body axis. The broad line in the g = 2 region, associated to isolated nanoparticles shows that at least 97% of the magnetic material is in the termite’s body (abdomen + thorax). The spectra temperature behavior is typical of synthetic superparamagnetic nanoparticles and also observed for the high field component of P.m. ant abdomen spectra \[4]. From the temperature dependence of the resonant field and spectral linewidths, the existence of magnetic nanoparticles 18.5 ± 0.3 nm in diameter and an effective magnetic anisotropy constant, Keff between 2.1 and 3.2 x 104 erg/cm3 are estimate. The sudden change in the double integrated spectra at about 100 K for N.o.^ is attributed to the Verwey transition. Since MR spectra of N.o. oriented parallel (N.o.//) or perpendicular (N.o.^) to the magnetic field ought to be due to the same particle system, the differences between these orientation behaviors can be related to the magnetic particles arrangement. An organized film-like particle system could account for this observation. The nanoparticles in the head could only be derived from biomineralization and/or cuticular contamination processes \[2] while in the body they could be due to biomineralization and the accumulation of ingested materials in the digestive apparatus. Although the latter case should not be related to a magnetic orientation process, the magnetic anisotropy changes observed and the suggested geometric arrangement indicate that some of the nanoparticles in N.o. body can involved with the magnetoreception process. Although there is no report on magnetoreception for N.o., it was observed in foraging of another termite species, Trinervitermes geminatus \[5]. These results present a novel application of MR to determine the organization and magnetic parameters of iron oxide particles in termites. \[1] D. Acosta-Avalos et al, Naturwissenchaften 88 (2001) 343-346. \[2] D. Acosta-Avalos et al, J. Exp. Biol. 202 (1999) 2687-2692. \[3]D.M.S. Esquivel et al, J. Mag. Mag.Mat. (2004) in press \[4] E. Wajnberg et al, Biophys. J. 78 (2000) 1018-1023. \[5] M. Rickli, R.H. Leuthold, Ethology 77 (1988) 209-216. ## **Dados do evento**
Tipo de evento
Congresso
Ano
2004
Participação
Não
Apresentação
Pôster
Título do trabalho
A magnetic resonance study of the Neocapritermes opacus termites
Agências de fomento
CNPq
Colaboradores
D. M. S. Esquivel
```json {"@context":"https://schema.org","@graph":[{"@id":"https://index.cbpf.br/#website","@type":"WebSite","description":"O CBPF INDEX é o sistema de acompanhamento da produção científica e tecnológica do CBPF. Nele é possível obter a lista de publicações de artigos, livros, relatórios técnicos, etc de toda a comunidade do CBPF.","inLanguage":"pt-BR","name":"CBPF Index","url":"https://index.cbpf.br/","publisher":{"@id":"https://index.cbpf.br/#identity"},"workTranslation":[{"@id":"https://index.cbpf.br/en#website"},{"@id":"https://index.cbpf.br/es#website"}]},{"@id":"https://index.cbpf.br/eventos/6ad2a76c639f62b11adbdc3b#webpage","@type":"WebPage","description":"O CBPF INDEX é o sistema de acompanhamento da produção científica e tecnológica do CBPF. Nele é possível obter a lista de publicações de artigos, livros, relatórios técnicos, etc de toda a comunidade do CBPF.","name":"5th International Conference on Biological Physics","url":"https://index.cbpf.br/eventos/6ad2a76c639f62b11adbdc3b","isPartOf":{"@id":"https://index.cbpf.br/#website"},"potentialAction":[{"@type":"ReadAction","target":["https://index.cbpf.br/eventos/6ad2a76c639f62b11adbdc3b"]}],"primaryImageOfPage":{"@id":"https://index.cbpf.br/#logo"}},{"@id":"https://index.cbpf.br/#identity","@type":"Organization","alternateName":"CBPF","description":"Unidade de pesquisa do Ministério da Ciência, Tecnologia e Inovação dedicada à pesquisa básica em Física, suas aplicações e à formação científica.","email":"web@cbpf.br","legalName":"Centro Brasileiro de Pesquisas Físicas/CBPF","name":"Centro Brasileiro de Pesquisas Físicas","taxID":"04.044.443/0001-35","telephone":"+55-21-2141-7100","url":"https://cbpf.br","address":{"@type":"PostalAddress","streetAddress":"Rua Dr. Xavier Sigaud, 150","addressLocality":"Rio de Janeiro","addressRegion":"RJ","postalCode":"22290-180","addressCountry":"BR"},"logo":{"@id":"https://index.cbpf.br/#logo"},"sameAs":["https://twitter.com/cbpf_mcti"]},{"@id":"https://index.cbpf.br/#logo","@type":"ImageObject","caption":"Centro Brasileiro de Pesquisas Físicas","contentUrl":"https://index.cbpf.br/icon-512x512-light.png","inLanguage":"pt-BR","url":"https://index.cbpf.br/icon-512x512-light.png"}]} ``` ## Sitemap See the full [sitemap](https://index.cbpf.br/sitemap.md) for all pages.