Infestação e danos de Cinara atlantica relacionados com o estado nutricional e hídrico em mudas de Pinus taeda.

Foi avaliada a resposta de populações de Cinara atlantica ao estado nutricional de mudas de Pinus taeda L., em condições de campo no município de Três Barras (SC), e ao estresse hídrico, em casa de vegetação em Colombo (PR). Em casa de vegetação, foram avaliados 4 tratamentos com 30 mudas cada: plantas não-estressadas (com 60% da capacidade de campo) e estressadas (com 30% da capacidade de campo), ambos com e sem insetos. Cada planta foi infestada com 10 ninfas de 3º e 4º instar. Semanalmente, era contado o número de afídeos, medidos a altura e o diâmetro de todas as plantas e acrescentado o volume de água correspondente. Em campo, foram plantadas 60 plantas, das quais, quinzenalmente, 15 plantas eram arrancadas ao acaso, contando-se o número de afídeos por planta e analisando-se o estado nutricional, durante dois meses. Constatou-se que o aumento do teor de nitrogênio nas mudas de P. taeda correlaciona-se diretamente com o aumento no número de insetos. As mudas com estresse hídrico apresentaram maiores teores de nitrogênio e incidência de pulgões. Em casa de vegetação, as plantas apresentaram menor crescimento em altura na presença de insetos, com ou sem estresse hídrico. As mudas infestadas apresentaram maior crescimento em diâmetro, independentemente do estresse hídrico, no tempo observado e condições do estudo

Primeiro relato do pulgão cerataphis brasiliensis (Hempel) (Hemiptera: Aphididae) atacando mudas de duas espécies de tucumanzeiro (Astrocaryum spp.): descrição e controle.

bitstream/item/31738/1/Com-tec-223.pdfVersão eletrônica disponível em papel

Modern meson--exchange potential and superfluid neutron star crust matter

In this work we study properties of neutron star crusts, where matter is expected to consist of nuclei surrounded by superfluid neutrons and a homogeneous background of relativistic electrons. The nuclei are disposed in a Coulomb lattice, and it is believed that the structure of the lattice influences considerably the specific heat of the neutronic matter inside the crust of a neutron star. Using a modern meson--exchange potential in the framework of a local--density approximation we calculate the neutronic specific heat accounting for various shapes of the Coulomb lattice, from spherical to non--spherical nuclear shapes. We find that a realistic nucleon--nucleon potential leads to a significant increase in the neutronic specific heat with respect to that obtained assuming a uniform neutron distribution. The increase is largest for the non--spherical phase of the crust. These results may have consequences for the thermal history of young neutron stars.Comment: Revtex, 5 pages, 4 figures included as uuencoded p

Role of ventricular tachycardia ablation in arrhythmogenic right ventricular cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is characterized by progressive fibro-fatty replacement of the myocardium that represents the substrate for recurrent sustained ventricular tachycardia (VT). These arrhythmias characterize the clinical course of a sizeable proportion of patients and have significant implications for their quality of life and long-term prognosis. Antiarrhythmic drugs are often poorly tolerated and usually provide incomplete control of arrhythmia relapses. Catheter ablation is a potentially effective strategy to treat frequent VT episodes and ICD shocks in ARVC patients. The aims of this review are to discuss the electrophysiological and electroanatomic substrates of ventricular tachycardia in patients with ARVC and to analyze the role of catheter ablation in their management with particular reference to selection of patients, technical issues, potential complications and outcomes

Dinoflagellate cysts production in the north-western Adriatic Sea

A sediment trap study was conducted in the Gulf of Venice, north-western Adriatic Sea, from April to December 2005 to assess relationships between planktonic dinoflagellates and cyst production. Every month, CTD profiles and discrete samplings for phytoplankton, nutrients and particulate matter were conducted. Cyst fluxes spanned from 90 to 127,600 cysts m-2 d-1 and major peaks were due to a small cyst attributed to cf. Biecheleria and to calcareous cysts of Scrippsiella trochoidea. A good correspondence between cyst fluxes in sediment traps and the presence of the corresponding vegetative cells in the water column was detected for Lingulodinium polyedrum, and species of the genera Spiniferites,Gonyaulax and Protoperidinium. A PCR method applied to surface sediment samples allowed the identification of a number of potentially harmful dinoflagellate cysts (Alexandrium minutum, A. tamutum, A. taylorii, Lingulodinium polyedrum and Protoceratium reticulatum)

TabVida: sistema computacional para cálculo de parâmetros biológicos e de crescimento populacional de afídeos.

bitstream/item/24483/1/Doc203.pd

Muons and emissivities of neutrinos in neutron star cores

In this work we consider the role of muons in various URCA processes relevant for neutrino emissions in the core region of neutron stars. The calculations are done for $\beta$--stable nuclear matter with and without muons. We find muons to appear at densities $\rho = 0.15$ fm$^{-3}$, slightly around the saturation density for nuclear matter $\rho_0 =0.16$ fm$^{-3}$. The direct URCA processes for nucleons are forbidden for densities below $\rho = 0.5$ fm$^{-3}$, however the modified URCA processes with muons $(n+N\rightarrow p+N +\mu +\overline{\nu}_{\mu}, p+N+\mu \rightarrow n+N+\nu_{\mu}$), where $N$ is a nucleon, result in neutrino emissivities comparable to those from $(n+N\rightarrow p+N +e +\overline{\nu}_e, p+N+e \rightarrow n+N+\nu_e$). This opens up for further possibilities to explain the rapid cooling of neutrons stars. Superconducting protons reduce however these emissivities at densities below $0.4$ fm$^{-3}$.Comment: 14 pages, Revtex style, 3 uuencoded figs include