Octopus insularis (Cephalopoda: Octopodidae) on the tropical coast of Brazil: where it lives and what it eats

Abstract Octopus insularis is the dominant octopus in the shallow tropical waters of the coast and oceanic islands in the North and Northeast of Brazil. Is the abundance, distribution, habitat and diet of this species on the continent the same as in oceanic islands? These factors were evaluated in seeking these answers at two areas of occurrence of Octopus insularis on the coast of Rio Grande do Norte, Brazil. Three main types of habitats were described where the species is concentrated, being: Deep Reefs (Reefs of Risca) (> 15 m), Flat Biogenic Plateaus (Restingas) (5-15 m) and Shallow Sedimentary Reefs (Pirangi reefs) (< 5 m). An aggregate spatial distribution was verified, along with bathymetric segregation in which small individuals occupied shallow areas. Regarding diet, O. insularis consumed mainly crustaceans (68%) in shallow reef areas, bivalves (86%) in biogenic plateau areas, and gastropods (33%) in deep reef areas. The characterization of new occurring habitats, such as the area of biogenic plateau, and changes in their diet due to habitat function have shown that O. insularis occupies a broader niche than has been described in literature to date, expanding our knowledge on the ecology and biology of this octopus species of economic interest

Specific heat amplitude ratios for anisotropic Lifshitz critical behaviors

We determine the specific heat amplitude ratio near a $m$-axial Lifshitz point and show its universal character. Using a recent renormalization group picture along with new field-theoretical $\epsilon_{L}$-expansion techniques, we established this amplitude ratio at one-loop order. We estimate the numerical value of this amplitude ratio for $m=1$ and $d=3$. The result is in very good agreement with its experimental measurement on the magnetic material $MnP$. It is shown that in the limit $m \to 0$ it trivially reduces to the Ising-like amplitude ratio.Comment: 8 pages, RevTex, accepted as a Brief Report in Physical Review

Aplicação de celulases imobilizadas nahidrólise de Brachiaria brizantha.

O objetivo deste trabalho foi desenvolver um biocatalisador para aplicação na hidrólise de holocelulose de braquiária

Geographic variability of Octopus insularis diet: from oceanic island to continental populations

A predator’s choice of prey can be affected by many factors. We evaluated various influences on population dietary composition, individual specialization and size of prey in Octopus insularis populations from 2 continental and 4 insular locations. We expected that habitat diversity would lead to diet heterogeneity. Furthermore, in keeping with MacArthur & Wilson’s (1967) theory of island biogeography, we expected that diet diversity would be lower around islands than on the coast of the mainland. Both predictions were confirmed when prey remains from octopus middens were examined. The 2 continental areas exhibited a richer habitat diversity and a wider variety of prey. Niche widths in the continental areas were 2.42 and 2.03, with the lowest niche widths exhibited by the population from the most distant oceanic islands (1.30, 0.85). We found variation in the proportion of specialist relative to generalist individuals across areas based on the proportional similarity index. The correlation between habitat diversity and niche width (R2 = 0.84) was highly significant, as was distance from the continental shelf and niche width (R2 = 0.89). This study reaffirms the central position of octopuses in the nearshore benthic ecosystem, and supports MacArthur & Wilson’s (1967) prediction of a lower diversity of species on islands—which applies not only to the species themselves, but also indirectly for the diet of their predators

Mitigation of Mombasa Grass (Megathyrsus maximus) dependence on nitrogen fertilization as a function of inoculation with Azospirillum brasilense.

ABSTRACT Using biological inputs to improve the efficiency of nitrogen fertilizers represents an alternative for the cultivation of grasses in tropical regions. Azospirillum brasilense is a species of plant growth promoting bacteria widely studied and used in inoculants. Thus, this study aimed to evaluate the performance of Mombasa grass ( Megathyrsus maximus ) in association with A. brasilense and nitrogen (N) fertilization. The study was conducted under field conditions in Araguaína-Tocantins State, between December 2017 and May 2018. The treatments were arranged in randomized blocks, in a 5 × 2 factorial arrangement, with five doses of N fertilization (0, 25, 50, 75, and 100 kg ha-1) combined with two inoculation treatments (inoculated and non inoculated), in four replicates. For the number of tillers and root production, the inoculation efficiency varied as a function of the supplied N doses. However, the percentage of leaf N was higher for inoculated plants regardless of the application of nitrogen. In the absence of nitrogen fertilization, it was possible to increase forage production by up to 36 % with inoculation

The irreducible unitary representations of the extended Poincare group in (1+1) dimensions

We prove that the extended Poincare group in (1+1) dimensions is non-nilpotent solvable exponential, and therefore that it belongs to type I. We determine its first and second cohomology groups in order to work out a classification of the two-dimensional relativistic elementary systems. Moreover, all irreducible unitary representations of the extended Poincare group are constructed by the orbit method. The most physically interesting class of irreducible representations corresponds to the anomaly-free relativistic particle in (1+1) dimensions, which cannot be fully quantized. However, we show that the corresponding coadjoint orbit of the extended Poincare group determines a covariant maximal polynomial quantization by unbounded operators, which is enough to ensure that the associated quantum dynamical problem can be consistently solved, thus providing a physical interpretation for this particular class of representations.Comment: 12 pages, Revtex 4, letter paper; Revised version of paper published in J. Math. Phys. 45, 1156 (2004

Avaliação de variáveis comportamentais como metodologia para estudo de organismos não alvo em milho Bt.

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Estrutura familiar e geração de renda em assentamentos rurais que desenvolvem atividade pecuária em Tomé-Açu e Paragominas no nordeste e sudeste paraense.

O estudo avaliou os produtores rurais envolvidos com a produção pecuária em assentamentos rurais localizados em Tomé-Açu e Paragominas no Nordeste e Sudeste paraense, respectivamente. Noventa e cinco produtores foram entrevistados quanto à liderança administrativa das propriedades, estado civil, migração, profissões anteriores antes da aquisição da propriedade, escolaridade, idade e renda. A liderança das propriedades é caracterizada por homens casados, ou em regime de união estável, imigrante da Região Norte e Nordeste. Em Paragominas os produtores são mais velhos, com maior índice de analfabetismo e pouco auxílio governamental. Em Tomé-Açu as famílias são mais numerosas e 20% delas recebem auxílio do governo. Os produtores de Tomé-Açu receberam mais subsídios governamentais pelo fato das famílias serem mais numerosas

Avaliação de práticas alternativas para manejo de hortas comunitárias.

Visando racionalizar a utilização de insumo s na prática de hortas comunitárias e viabilizar o aproveitamento de adubos orgânicos, bem como do uso de extratos vegetais no controle de problemas fitossanitários e oferecer alimentos saudáveis, gerados com tecnologias para o pequeno produtor, avaliou-se algumas práticas alternativas realizadas em uma horta comunitária localizada no município de Petrolina-PE. As espécies cultivadas foram quiabo, beterraba, rabanete, coentro, alface, couve-flor, cebolinha, berinjela e cenoura. As técnicas avaliadas foram: 1- consorcio com até quatro espécies, 2- compostagem com 70% de terra vegetal e 25% de esterco caprino, 3- irrigação por regadores com água tratada (COMPESA) em tanques de alvenaria, e 4- manejo fitossanitário com extrato vegetal, composto de 50 g de fumo 10 g de pimenta malagueta, triturados, 1 Kg de folha de angico inteira, 5 L de água, 10 L de álcool e 20 g de sabão comum em barra, cortado em pedaços pequenos. No seu uso, o extrato foi diluído em 10 L de água. Os resultados são de elevados índices de produtividade com 6 a 13 Kg/m2 entre as espécies trabalhadas, sem problemas fitossanitário, oferecendo alimento para 30 família.Suplemento. Edição de Resumos expandidos e palestras do 43. Congresso Brasileiro de Olericultura, jul. 2003