5 resultados para Scott, Walter, 1771-1832

em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo


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The genus Lamprosoma Kirby, 1818 includes 128 neotropical species and 54 of them are recorded from Brazil (Monros, 1960). The first species with a described larva was L. seraphinum Lacordaire. After that, larvae and pupae of three species were described: L. bicolor Kirby, 1818, L. chorisiae Monros, 1948 and L. azureum Germar, 1824. Fiebrig (1910) described the larva of L. seraphinum Lacordaire, collected on Teminalia hassleriana Chod. (Combretaceae) of Paraguay. Moreira (1913) described L. bicolor collected on Terminalia catappa L., in Rio de Janeiro. According to him, this tree was introduced from Molucas Islands, in Oceania. He also considered it probable that L. bicolor lived on one native species of Terminalia or on another species of Combretaceae and adaptated itself to live on Terminalia catappa. Monros (1949) described L. chorisiae collected on Chorisia speciosa and Ch. insignis [ Ceiba speciosa (A. St.-Hil., A. Juss. & Cambess.) Ravenna and Ceiba insignis (Kunth) P. E. Gibbs & J. Semir] (Bombacaceae) ("" palos borrachos"") in Tucuman. Caxambu and Almeida (1999) described L. azureum collected on Psidium cattleianum Sabine (Myrtaceae)(""araca""), in Parana state. Herein, the larva and pupa of L. amethystinum collected on Terminalia catappa amendoeira-da-praia"", "" chapeu-de-sol"") in Campinas, Sao Paulo state, are described and illustrated.

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This study documents one of the slowest feeding behaviors ever recorded for a muricid gastropod in one of the most biotically rigorous regions on the planet. In Pacific Panama, Vitularia salebrosa attacks mollusks by drilling through their shells. The duration of attacks estimated by isotope sclerochronology of oyster shells collected during attacks in progress range from 90 to 230 days, while experimental observation of interactions documented one attack greater than 103 days. The prolonged nature of attacks suggests that V. salebrosa is best characterized as an ectoparasite than as a predator, which is the ancestral condition in the Muricidae. An ectoparasitic lifestyle is also evident in the unusual interaction traces of this species, which include foot scars, feeding tunnels and feeding tubes, specialized soft anatomy, and in the formation of male-female Pairs, which is consistent with protandrous hermaphroditism, as is typical in sedentary gastropods. To delay death of its host, V. salebrosa targets renewable resources when feeding, such as blood and digestive glands. A congener, Vitularia miliaris from the Indo-Pacific, has an identical feeding biology The origin and persistence of extremely slow feeding in the tropics challenges our present understanding of selective pressures influencing the evolution of muricid feeding behaviors and morphological adaptations. Previously, it has been suggested that faster feeding is advantageous because it permits predators to spend a greater proportion of time hiding in enemy-free refugia or to take additional prey, the energetic benefits of which could be translated into increased fecundity or defenses. The benefits of exceptionally slow feeding have received little consideration. In the microhabitat preferred by V. salebrosa (beneath boulders), it is possible that prolonged interactions with hosts decrease vulnerability to enemies by reducing the frequency of risky foraging events between feedings . Ectoparasitic feeding through tunnels by V. salebrosa may also reduce competitive interactions with kleptoparasites (e.g., crabs, snails) that steal food through the gaped valves of dead or dying hosts.

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The morphology and anatomy of Vitularia salebrosa, a muricid ectoparasitic on other mollusks, are investigated based on study of specimens from western Panama. Distinctive characters of this species include the small size of the buccal mass and radular apparatus, simplification of the odontophore muscles and diminished lateral teeth of the radula; all elongated, narrow proboscis; narrow digestive tract and a differentiable glandular region at the beginning of the posterior esophagus. These traits are consistent with adaptive specialization for an ectoparasitic life history.

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We present measurements of Underlying Event observables in pp collisions at root s = 0 : 9 and 7 TeV. The analysis is performed as a function of the highest charged-particle transverse momentum p(T),L-T in the event. Different regions are defined with respect to the azimuthal direction of the leading (highest transverse momentum) track: Toward, Transverse and Away. The Toward and Away regions collect the fragmentation products of the hardest partonic interaction. The Transverse region is expected to be most sensitive to the Underlying Event activity. The study is performed with charged particles above three different p(T) thresholds: 0.15, 0.5 and 1.0 GeV/c. In the Transverse region we observe an increase in the multiplicity of a factor 2-3 between the lower and higher collision energies, depending on the track p(T) threshold considered. Data are compared to PYTHIA 6.4, PYTHIA 8.1 and PHOJET. On average, all models considered underestimate the multiplicity and summed p(T) in the Transverse region by about 10-30%.

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The ALICE experiment at the LHC has studied J/psi production at mid-rapidity in pp collisions at root s = 7 TeV through its electron pair decay on a data sample corresponding to an integrated luminosity L-int = 5.6 nb(-1). The fraction of J/psi from the decay of long-lived beauty hadrons was determined for J/psi candidates with transverse momentum p(t) > 1,3 GeV/c and rapidity vertical bar y vertical bar < 0.9. The cross section for prompt J/psi mesons, i.e. directly produced J/psi and prompt decays of heavier charmonium states such as the psi(2S) and chi(c) resonances, is sigma(prompt J/psi) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 8.3 +/- 0.8(stat.) +/- 1.1 (syst.)(-1.4)(+1.5) (syst. pol.) mu b. The cross section for the production of b-hadrons decaying to J/psi with p(t) > 1.3 GeV/c and vertical bar y vertical bar < 0.9 is a sigma(J/psi <- hB) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 1.46 +/- 0.38 (stat.)(-0.32)(+0.26) (syst.) mu b. The results are compared to QCD model predictions. The shape of the p(t) and y distributions of b-quarks predicted by perturbative QCD model calculations are used to extrapolate the measured cross section to derive the b (b) over bar pair total cross section and d sigma/dy at mid-rapidity.