Anatomia comparada de duas especies nativas de Manihot Mill. (Euphorbiaceae)

Orientador : Hermogenes de Freitas Leitão FilhoDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de BiologiaResumo: Este trabalho consiste num estudo anatômico comparativo dos órgãos vegetativos de duas espécies nativas de Mani - hot. Uma delas, M. caerulescens, ocorre em vegetação de cerrado, enquanto a outra, M. pilosa é uma espécie de mata. Coletou-se material de plantas in situ afim de evitar quaisquer das alterações estruturais produzidas pelo cultivo. Notaram-se diferenças anatômicas importantes na folha. M. caerulescens apresenta uma cutícula espessa ao passo que na M. pilosa, a cutícula é muito delgada. Depressões ou aberturas na epiderme são comuns na espécie do cerrado e raras na espécie de mata. O número de estômatos na epiderme abaxial e o número de células com alto conteúdo tanóide são elevados na espécie M. caerulescens. Esta espécie também apresentou esclerênquima mais desenvolvido. A estrutura anatômica do caule é semelhante em ambas as espécies. As únicas diferenças relevantes são a cutícula mais espessa e o número elevado de células ricas em taninos na M. caerulescens. A região nodal de ambas as espécies é semelhante. A estrutura primária da raiz foi estudada somente na M. pilosa e é muito semelhante àquela já descrita na literatura referente à M. esculenta. Quanto a estrutura secundária, as duas espécies são semelhantes. Células ricas em taninos são mais comuns na M, caerulescens. A anatomia da região de transição foi estudada somente na M. pilosa, tendo-se verificado ser ela semelhante à da M. esculentaAbstract: A comparative anatomical study of the vegetative organs of two native species of Manihot, has been carried out. One of the species, M. caerulescens, occurs in "cerrado" vegetation while the other, M. pilosa is a forest species. Material was collected from plants in situ in order to avoid any of the structural alterations produced by cultivation. Important anatomical differences have been noticed on the leaf. M. caerulescens has a thick cuticle while in M. pilosa, the cuticle is much thinner. Depressions or openings in the epidermis were common in the "cerrado" species and rare in the forest species. The number of stomata on the abaxial epidermis and the number of cells with a high tannin content are both higher in M. caerulescens. This species also has more abundant sclerenchyma. The anatomical structure of the stem is similar in both species. The only diferences worth mentioning are the thicker cuticle and larger number of tannin-rich cells in M. caerulescens. The nodal region of both species is similar. The primary structure of the root has been studied only in M. pilosa and is very similar to that already described in literature for M. esculenta. The two species are similar as far as secundary structure is concerned. Tannins-rich cells are more common in M. caerulescens. The anatomy of the transition region has been studied only in M. pilosa and was found to limilar to that described for M. esculentaMestradoMestre em Biologia Vegeta

Morfologia e anatomia foliar de Bauhinia curvulha Benth. (Leguminosae-Caesalpinioideae)

Foi realizado o estudo morfológico e anatômico da folha de Bauhinia cumula Benth., espécie de cerrado. As observações foram feitas em folhas adultas, tratadas segundo a metodologia usual utilizada em anatomia vegetal. Foi observado que a espécie apresenta as seguintes características: folhas bilobadas cuja incisão foliar chega próximo à região motora; um par de estipulas membranáceas; um par de nectários extraflorais, localizadaos na base do pulvino proximal; a venação possui padrão acródomo; o pecíolo, que possui dois pulvinos, um proximal e um distai, apresenta epiderme contendo grande quantidade de tricomas tecto res simples e glândulas; a lâmina foliar é anfiestomática com predomínio de estômatos dos tipos anomocítico e paracítico; a epiderme adaxial é monoestratificada, subpapilosa, desprovida de tricomas tectores simples e glândulas; a epiderme abaxial é subpapilosa, apresentando numerosos tricomas tectores simples e glândulas; e o mesofilo é formado predominantemente por parênquima paliçádico.<br>A morphological and anatomical study of Bauhinia curvula Benth. leaf, a cerrado spe-cies, was perfomed. The observations, in grown up leaves, prepared according to the costumary methodology used in plant anatomy, showed the following characteristics of the species: bilobed leaves with foliar incision close to the motor region; one pair of membranaceous stipules; one pair of extrafloral nectaries located on the basis of the proximal pulvinus; acrodromous patterns of leaf venetion; the petiole, which has two pulvinus, one proximal and one distal, has an epidermis containing large quantities of simple tector trichomes and glands; the leaf blade, amphiestomatic, with predominance of anomocytic and paracytic stomata; the adaxial epidermis uniserial, sub papillose, without tector trichomes and glands; the abaxial epiderms, sub-papillose, presents a high number of simple trichomes and glands; and the mesophyll with a basic composition of palisadic parenchyma

Where Brain, Body and World Collide

The production cross section of electrons from semileptonic decays of beauty hadrons was measured at mid-rapidity (|y| &lt; 0.8) in the transverse momentum range 1 &lt; pt &lt; 8 Gev/c with the ALICE experiment at the CERN LHC in pp collisions at a center of mass energy sqrt{s} = 7 TeV using an integrated luminosity of 2.2 nb^{-1}. Electrons from beauty hadron decays were selected based on the displacement of the decay vertex from the collision vertex. A perturbative QCD calculation agrees with the measurement within uncertainties. The data were extrapolated to the full phase space to determine the total cross section for the production of beauty quark-antiquark pairs

Charge correlations using the balance function in Pb?Pb collisions at ?sNN = 2.76 TeV

In high-energy heavy-ion collisions, the correlations between the emitted particles can be used as a probe to gain insight into the charge creation mechanisms. In this article, we report the first results of such studies using the electric charge balance function in the relative pseudorapidity \Delta\eta and azimuthal angle \Delta\phi in Pb-Pb collisions at sqrt{s_{NN}} = 2.76 TeV with the ALICE detector at the Large Hadron Collider. The width of the balance function decreases with growing centrality (i.e. for more central collisions) in both projections. This centrality dependence is not reproduced by HIJING, while AMPT, a model which incorporates strings and parton rescattering, exhibits qualitative agreement with the measured correlations in \Delta\phi but fails to describe the correlations in \Delta\eta. A thermal blast wave model incorporating local charge conservation and tuned to describe the p_T spectra and v_2 measurements reported by ALICE, is used to fit the centrality dependence of the width of the balance function and to extract the average separation of balancing charges at freeze-out. The comparison of our results with measurements at lower energies reveals an ordering with sqrt{s_{NN}}: the balance functions become narrower with increasing energy for all centralities. This is consistent with the effect of larger radial flow at the LHC energies but also with the late stage creation scenario of balancing charges. However, the relative decrease of the balance function widths in \Delta\eta and \Delta\phi with centrality from the highest SPS to the LHC energy exhibits only small differences. This observation cannot be interpreted solely within the framework where the majority of the charge is produced at a later stage in the evolution of the heavy-ion collision