RESUMO

Abstract The native stands of 'candeia' (Eremanthus erythropappus) have been explored through management plans due to the economic potential of essential oil. The rescue of adult trees, as well as the application of silvicultural techniques that favor the restoration of the stand, can contribute to the genetic conservation of this species. This study's objective was to assess the efficiency of propagation techniques for the rescue of 26 matrices of 'candeia' in a natural managed stand and discussion about the rhizogenesis. In August 2017, trees were induced to regrowth by coppice, followed by exposure and scarification of roots. The emergence of shoots and morphology were evaluated according to the origin (i.e., stump or root). After that period, 19 matrices had their sprouts collected for the preparation of apical cuttings. Indole-3-butyric acid (IBA) was applied at the base of the cuttings. Cutting survival at greenhouse exit (GE), rooting at shade house exit (SHE), morphology and root anatomy were evaluated. In 189 days, the scarification of roots promoted 76.92% of budding. The percentage of sprouted matrices, number of shoots per matrice, length, diameter, and shoot length/diameter ratio increased over time. Only 12.2% of the cuttings survived in GE, and of these, 7.9% rooted in SHE. The cutting resulted in the formation of a clonal mini-garden of 'candeia', with seven of the 19 matrices submitted to propagation. The anatomical analyses showed that bud formation occurs from cell redifferentiation in the phloem parenchyma, and presence of crystals on the walls of the vessel elements of the secondary xylem. The shoots induction from scarification of roots could be used as a silvicultural practice for the reestablishment of the native fragments handle.

Resumo Os povoamentos nativos de candeia (Eremanthus erythropappus) vêm sendo explorados por planos de manejo devido ao potencial econômico do óleo essencial. O resgate de árvores adultas, bem como a aplicação de técnicas silviculturais que favoreçam o restabelecimento do povoamento podem contribuir para a conservação genética dessa espécie. O objetivo desse trabalho foi avaliar a eficiência de técnicas de propagação para o resgate de 26 matrizes de candeia em um povoamento natural manejado e discutir sobre a rizogênese. Em agosto de 2017, as árvores foram induzidas à rebrota por meio da decepa, seguida da exposição e escarificação das raízes. A emissão brotações e morfologia foram avaliadas de acordo com a origem (toco ou raiz). Após esse período, 19 matrizes tiveram as brotações recolhidas para o preparo de estacas apicais, que foram tratadas com ácido indolbutírico (AIB). A sobrevivência das estacas na saída da casa de vegetação (SCV), o enraizamento na saída da casa de sombra (SCS), a morfologia e a anatomia da raiz foram avaliados. Aos 189 dias, a escarificação das raízes resultou em 76,92% de emissão de brotos. O percentual de matrizes brotadas, número de brotos por matriz, comprimento, diâmetro e relação comprimento/diâmetro dos brotos aumentaram ao longo do período avaliado. Somente 12,2% das estacas sobreviveram na SCV e 7,9% enraizaram na SCS. A estaquia resultou na formação de um minijardim clonal de candeia com sete das dezenove matrizes submetidas à propagação. As análises anatômicas mostraram a diferenciação das células na região do parênquima floemático e a presença de cristais de inulina nas paredes dos elementos de vaso do xilema secundário. A indução de brotos radiculares pode ser usada como prática silvicultural visando o restabelecimento de fragmentos nativos manejados.

Assuntos

RESUMO

The native stands of candeia (Eremanthus erythropappus) have been explored through management plans due to the economic potential of essential oil. The rescue of adult trees, as well as the application of silvicultural techniques that favor the restoration of the stand, can contribute to the genetic conservation of this species. This studys objective was to assess the efficiency of propagation techniques for the rescue of 26 matrices of candeia in a natural managed stand and discussion about the rhizogenesis. In August 2017, trees were induced to regrowth by coppice, followed by exposure and scarification of roots. The emergence of shoots and morphology were evaluated according to the origin (i.e., stump or root). After that period, 19 matrices had their sprouts collected for the preparation of apical cuttings. Indole-3-butyric acid (IBA) was applied at the base of the cuttings. Cutting survival at greenhouse exit (GE), rooting at shade house exit (SHE), morphology and root anatomy were evaluated. In 189 days, the scarification of roots promoted 76.92% of budding. The percentage of sprouted matrices, number of shoots per matrice, length, diameter, and shoot length/diameter ratio increased over time. Only 12.2% of the cuttings survived in GE, and of these, 7.9% rooted in SHE. The cutting resulted in the formation of a clonal mini-garden of candeia, with seven of the 19 matrices submitted to propagation. The anatomical analyses showed that bud formation occurs from cell redifferentiation in the phloem parenchyma, and presence of crystals on the walls of the vessel elements of the secondary xylem. The shoots induction from scarification of roots could be used as a silvicultural practice for the reestablishment of the native fragments handle.(AU)

Os povoamentos nativos de candeia (Eremanthus erythropappus) vêm sendo explorados por planos de manejo devido ao potencial econômico do óleo essencial. O resgate de árvores adultas, bem como a aplicação de técnicas silviculturais que favoreçam o restabelecimento do povoamento podem contribuir para a conservação genética dessa espécie. O objetivo desse trabalho foi avaliar a eficiência de técnicas de propagação para o resgate de 26 matrizes de candeia em um povoamento natural manejado e discutir sobre a rizogênese. Em agosto de 2017, as árvores foram induzidas à rebrota por meio da decepa, seguida da exposição e escarificação das raízes. A emissão brotações e morfologia foram avaliadas de acordo com a origem (toco ou raiz). Após esse período, 19 matrizes tiveram as brotações recolhidas para o preparo de estacas apicais, que foram tratadas com ácido indolbutírico (AIB). A sobrevivência das estacas na saída da casa de vegetação (SCV), o enraizamento na saída da casa de sombra (SCS), a morfologia e a anatomia da raiz foram avaliados. Aos 189 dias, a escarificação das raízes resultou em 76,92% de emissão de brotos. O percentual de matrizes brotadas, número de brotos por matriz, comprimento, diâmetro e relação comprimento/diâmetro dos brotos aumentaram ao longo do período avaliado. Somente 12,2% das estacas sobreviveram na SCV e 7,9% enraizaram na SCS. A estaquia resultou na formação de um minijardim clonal de candeia com sete das dezenove matrizes submetidas à propagação. As análises anatômicas mostraram a diferenciação das células na região do parênquima floemático e a presença de cristais de inulina nas paredes dos elementos de vaso do xilema secundário. A indução de brotos radiculares pode ser usada como prática silvicultural visando o restabelecimento de fragmentos nativos manejados.(AU)

Assuntos

RESUMO

A nodal-line semimetal (NLSM) is suppressed in the presence of spin-orbit coupling unless it is protected by a nonsymmorphic symmetry. We show that two-dimensional (2D) materials can realize robust NLSMs when vacancies are introduced on the lattice. As a case study we investigate borophene, a boron honeycomb-like sheet. While the Dirac cones of pristine borophene are shown to be gapped out by spin-orbit coupling and by magnetic exchange, robust nodal lines (NLs) emerge in the spectrum when selected atoms are removed. We propose an effective 2D model and a symmetry analysis to demonstrate that these NLs are topological and protected by a nonsymmorphic glide plane. Our findings offer a paradigm shift to the design of NLSMs: instead of searching for nonsymmorphic materials, robust NLSMs may be realized simply by removing atoms from ordinary symmorphic crystals.

RESUMO

In this paper, we report structural, electronic and optical properties of cubane (C8H8) and cubanoids (cubane-like molecules) using Density Functional Theory (DFT). The cubanoids are cubanes for which Carbon atoms have been substituted by Nitrogen (N), Phosphorus (P), Boron (B), Silicon (Si), Arsenic (As), Antimony (Sb) or Bismuth (Bi) atoms. These molecules presented exceptional stability with several different symmetry point groups, being the majority Td. All calculated vibrational frequencies are positive for any studied molecules indicating that all these structures are in a stable state. The HOMO-LUMO gaps and DOS were calculated converged towards to values between 1.87 eV and 5.61 eV, actually showing promising electronic properties (Just for comparison, the cubane energy gap is 7.50 eV). The optical absorptions were also calculated for the cubanoid structure using the Time-Dependent Density Functional Theory (TD-DFT). Their dependence on the wavelength is analyzed, where five of theses structures absorb on the visible region. Finally, the extrapolation of thermodynamic properties indicates that these cubanoid could be potentially synthesized spontaneously, where four structures, the synthesis would occur for temperatures below 400 K, while for Si4Bi4H4 structure, the synthesis would occur at room temperature.

Assuntos

RESUMO

The native stands of 'candeia' (Eremanthus erythropappus) have been explored through management plans due to the economic potential of essential oil. The rescue of adult trees, as well as the application of silvicultural techniques that favor the restoration of the stand, can contribute to the genetic conservation of this species. This study's objective was to assess the efficiency of propagation techniques for the rescue of 26 matrices of 'candeia' in a natural managed stand and discussion about the rhizogenesis. In August 2017, trees were induced to regrowth by coppice, followed by exposure and scarification of roots. The emergence of shoots and morphology were evaluated according to the origin (i.e., stump or root). After that period, 19 matrices had their sprouts collected for the preparation of apical cuttings. Indole-3-butyric acid (IBA) was applied at the base of the cuttings. Cutting survival at greenhouse exit (GE), rooting at shade house exit (SHE), morphology and root anatomy were evaluated. In 189 days, the scarification of roots promoted 76.92% of budding. The percentage of sprouted matrices, number of shoots per matrice, length, diameter, and shoot length/diameter ratio increased over time. Only 12.2% of the cuttings survived in GE, and of these, 7.9% rooted in SHE. The cutting resulted in the formation of a clonal mini-garden of 'candeia', with seven of the 19 matrices submitted to propagation. The anatomical analyses showed that bud formation occurs from cell redifferentiation in the phloem parenchyma, and presence of crystals on the walls of the vessel elements of the secondary xylem. The shoots induction from scarification of roots could be used as a silvicultural practice for the reestablishment of the native fragments handle.

Assuntos

RESUMO

Abstract The native stands of candeia (Eremanthus erythropappus) have been explored through management plans due to the economic potential of essential oil. The rescue of adult trees, as well as the application of silvicultural techniques that favor the restoration of the stand, can contribute to the genetic conservation of this species. This studys objective was to assess the efficiency of propagation techniques for the rescue of 26 matrices of candeia in a natural managed stand and discussion about the rhizogenesis. In August 2017, trees were induced to regrowth by coppice, followed by exposure and scarification of roots. The emergence of shoots and morphology were evaluated according to the origin (i.e., stump or root). After that period, 19 matrices had their sprouts collected for the preparation of apical cuttings. Indole-3-butyric acid (IBA) was applied at the base of the cuttings. Cutting survival at greenhouse exit (GE), rooting at shade house exit (SHE), morphology and root anatomy were evaluated. In 189 days, the scarification of roots promoted 76.92% of budding. The percentage of sprouted matrices, number of shoots per matrice, length, diameter, and shoot length/diameter ratio increased over time. Only 12.2% of the cuttings survived in GE, and of these, 7.9% rooted in SHE. The cutting resulted in the formation of a clonal mini-garden of candeia, with seven of the 19 matrices submitted to propagation. The anatomical analyses showed that bud formation occurs from cell redifferentiation in the phloem parenchyma, and presence of crystals on the walls of the vessel elements of the secondary xylem. The shoots induction from scarification of roots could be used as a silvicultural practice for the reestablishment of the native fragments handle.

Resumo Os povoamentos nativos de candeia (Eremanthus erythropappus) vêm sendo explorados por planos de manejo devido ao potencial econômico do óleo essencial. O resgate de árvores adultas, bem como a aplicação de técnicas silviculturais que favoreçam o restabelecimento do povoamento podem contribuir para a conservação genética dessa espécie. O objetivo desse trabalho foi avaliar a eficiência de técnicas de propagação para o resgate de 26 matrizes de candeia em um povoamento natural manejado e discutir sobre a rizogênese. Em agosto de 2017, as árvores foram induzidas à rebrota por meio da decepa, seguida da exposição e escarificação das raízes. A emissão brotações e morfologia foram avaliadas de acordo com a origem (toco ou raiz). Após esse período, 19 matrizes tiveram as brotações recolhidas para o preparo de estacas apicais, que foram tratadas com ácido indolbutírico (AIB). A sobrevivência das estacas na saída da casa de vegetação (SCV), o enraizamento na saída da casa de sombra (SCS), a morfologia e a anatomia da raiz foram avaliados. Aos 189 dias, a escarificação das raízes resultou em 76,92% de emissão de brotos. O percentual de matrizes brotadas, número de brotos por matriz, comprimento, diâmetro e relação comprimento/diâmetro dos brotos aumentaram ao longo do período avaliado. Somente 12,2% das estacas sobreviveram na SCV e 7,9% enraizaram na SCS. A estaquia resultou na formação de um minijardim clonal de candeia com sete das dezenove matrizes submetidas à propagação. As análises anatômicas mostraram a diferenciação das células na região do parênquima floemático e a presença de cristais de inulina nas paredes dos elementos de vaso do xilema secundário. A indução de brotos radiculares pode ser usada como prática silvicultural visando o restabelecimento de fragmentos nativos manejados.

Assuntos

RESUMO

The phylum Ciliophora is organized in 14 classes with ~8,000 described species ( Gao et al., 2016 ). Among unicellular microeukaryotes, ciliates are the most specialized, diversified and with the highest complexity in terms of cellular organization ( Puytorac, 1994 ). They typically occupy basal trophic levels and display a wide geographical distribution occurring in almost all environments such as marine, fresh and brackish waters, and also in edaphic systems like soils, mosses and lichens ( Lynn, 2008 ). Their diversity in lotic systems have been extensively studied in the northern hemisphere because of their potential use as water quality bioindicators ( Wiackowski, 1981 ; Primc, 1988 ; Groliére et al., 1990; Madoni, 2005 ). However, scarce information is available in literature about their diversity in aquatic ecosystems in Brazil, even though its privileged hydrological condition. The access to ciliate diversity and biogeography is a challenge tasks because they are diminute organisms, difficult to identify ( Finlay and Fenchel, 1999 ), there is a lack of experienced specialists ( Foissner, 2006 ) and a number of species stay encysted for most of their life cycles ( Foissner, 2004 ). In Brazil, significant works were performed with this emphasis such as conducted in Rio Grande do Sul (Safi et al., 2014), Paraná ( Pauleto et al., 2009 ; Buosi et al., 2011 ; Velho et al., 2005 , 2013 ), São Paulo ( Bagantini et al., 2013 ; Regali-Seleghim et al., 2011 ), Pará ( Castro et al., 2014 ), Minas Gerais ( Dias et al., 2008 , 2010 ) and Rio de Janeiro ( Paiva and Silva-Neto, 2004a , b ) states. Inventory studies constitute the first step for development of applied biotechnological usage of ciliates. Regali-Seleghim et al. (2011) highlight the importance of more works surveying the diversity of ciliates in less studied regions of Brazil given their ecological importance. Moreover, establishment of in vitrocultures will contribute with information to biomonitoring programs ( Madoni and Romeo, 2006 ; Shi et al., 2012 ) and for better evaluation of the biotechnological potential of these organisms ( Mansano et al., 2016 ). This present work aimed to survey the diversity of the species of ciliated protists in a neotropical lotic urban system located in Southern region of Minas Gerais state, Brazil.(AU)

RESUMO

The aim of this study was to jointly show the results of three independent ecotoxicological studies performed to investigate pollutants in three Brazilian tropical reservoirs undergoing accelerated eutrophication. In order to accomplish this goal, the full toxicity identification and evaluation procedure (TIE approach) was performed, at Pampulha (Minas Gerais State) and Salto Grande and Barra Bonita reservoirs (São Paulo State). Acute and chronic toxicity tests were performed using the cladocerans Daphnia similis and Ceriodaphnia dubia (exotic) and Daphnia laevis and Ceriodaphnia silvestrii (native) as test organisms. Results from TIE procedure stage I indicated the existence of nonpolar organic and filterable compounds in the water from Pampulha, probably cyanotoxins, and oxidants as part of the toxic agents. TIE results for sediments identified ammonia (Pampulha and Salto Grande), organic compounds (Pampulha), metals (Pampulha, Barra Bonita, and Salto Grande), and acidity (Salto Grande) as responsible for toxicity. Whole-sediment remediation experiments for Pampulha reservoir confirmed, through reproduction decrease, ammonia and organic compounds as contaminants. Such pollutants represent threats to aquatic biota and must be prevented. Higher temperatures as predicted from global climate change will severely affect tropical shallow reservoirs, accelerating eutrophication, the release of contaminants from sediments, and increasing toxicity.

Assuntos

RESUMO

Abstract The native stands of candeia (Eremanthus erythropappus) have been explored through management plans due to the economic potential of essential oil. The rescue of adult trees, as well as the application of silvicultural techniques that favor the restoration of the stand, can contribute to the genetic conservation of this species. This studys objective was to assess the efficiency of propagation techniques for the rescue of 26 matrices of candeia in a natural managed stand and discussion about the rhizogenesis. In August 2017, trees were induced to regrowth by coppice, followed by exposure and scarification of roots. The emergence of shoots and morphology were evaluated according to the origin (i.e., stump or root). After that period, 19 matrices had their sprouts collected for the preparation of apical cuttings. Indole-3-butyric acid (IBA) was applied at the base of the cuttings. Cutting survival at greenhouse exit (GE), rooting at shade house exit (SHE), morphology and root anatomy were evaluated. In 189 days, the scarification of roots promoted 76.92% of budding. The percentage of sprouted matrices, number of shoots per matrice, length, diameter, and shoot length/diameter ratio increased over time. Only 12.2% of the cuttings survived in GE, and of these, 7.9% rooted in SHE. The cutting resulted in the formation of a clonal mini-garden of candeia, with seven of the 19 matrices submitted to propagation. The anatomical analyses showed that bud formation occurs from cell redifferentiation in the phloem parenchyma, and presence of crystals on the walls of the vessel elements of the secondary xylem. The shoots induction from scarification of roots could be used as a silvicultural practice for the reestablishment of the native fragments handle.

Resumo Os povoamentos nativos de candeia (Eremanthus erythropappus) vêm sendo explorados por planos de manejo devido ao potencial econômico do óleo essencial. O resgate de árvores adultas, bem como a aplicação de técnicas silviculturais que favoreçam o restabelecimento do povoamento podem contribuir para a conservação genética dessa espécie. O objetivo desse trabalho foi avaliar a eficiência de técnicas de propagação para o resgate de 26 matrizes de candeia em um povoamento natural manejado e discutir sobre a rizogênese. Em agosto de 2017, as árvores foram induzidas à rebrota por meio da decepa, seguida da exposição e escarificação das raízes. A emissão brotações e morfologia foram avaliadas de acordo com a origem (toco ou raiz). Após esse período, 19 matrizes tiveram as brotações recolhidas para o preparo de estacas apicais, que foram tratadas com ácido indolbutírico (AIB). A sobrevivência das estacas na saída da casa de vegetação (SCV), o enraizamento na saída da casa de sombra (SCS), a morfologia e a anatomia da raiz foram avaliados. Aos 189 dias, a escarificação das raízes resultou em 76,92% de emissão de brotos. O percentual de matrizes brotadas, número de brotos por matriz, comprimento, diâmetro e relação comprimento/diâmetro dos brotos aumentaram ao longo do período avaliado. Somente 12,2% das estacas sobreviveram na SCV e 7,9% enraizaram na SCS. A estaquia resultou na formação de um minijardim clonal de candeia com sete das dezenove matrizes submetidas à propagação. As análises anatômicas mostraram a diferenciação das células na região do parênquima floemático e a presença de cristais de inulina nas paredes dos elementos de vaso do xilema secundário. A indução de brotos radiculares pode ser usada como prática silvicultural visando o restabelecimento de fragmentos nativos manejados.

RESUMO

Cylindrospermopsis raciborskii is a cyanobacterium distributed worldwide that is known to produce cyanotoxins. Some of the Brazilian strains can produce saxitoxins (STXs), which are classified as neurotoxins and can paralyze cladocerans .Daphnia laevis is a cladoceran with a wide distribution in the Americas and has been studied as a possible test-organism in toxicity bioassays. The present work tested the acute effect on D laevis mobility when fed a saxitoxin-producing (STX and neoSTX) C. raciborskii strain, CYRF-01, and compared the results with the effects of a non-toxic strain (NPCS-1). Neonates (6-24 hours after birth) were exposed to concentrations of C. raciborskii varying from 102 to 106 cells·mL-1 of each strain for up to three hours. The cladocerans were then transferred to a medium without toxic filaments for 24 hours. Only the organisms exposed to the STX-producing strain showed signs of the immobilization of swimming movements, confirming the effects of the toxins. There was a linear correlation between the time required to induce stopping the swimming movement, with a shorter time to needed to induce immobilization at a higher the concentration; this correlation was inverse to the time required to recover the swimming movements (longer at higher concentrations, p < 0.1). D. laevis is a tropical and subtropical species with great potential for use in toxicity tests for the detection of STXs, despite being native to and found in a great array of freshwater bodies. This is the first assay testing STX-producing and non-producing C. raciborskii strains on D. laevis, species that are both found in Brazilian ecosystems.

Assuntos

RESUMO

Cylindrospermopsis raciborskii is a cyanobacterium distributed worldwide that is known to produce cyanotoxins. Some of the Brazilian strains can produce saxitoxins (STXs), which are classified as neurotoxins and can paralyze cladocerans .Daphnia laevis is a cladoceran with a wide distribution in the Americas and has been studied as a possible test-organism in toxicity bioassays. The present work tested the acute effect on D laevis mobility when fed a saxitoxin-producing (STX and neoSTX) C. raciborskii strain, CYRF-01, and compared the results with the effects of a non-toxic strain (NPCS-1). Neonates (6-24 hours after birth) were exposed to concentrations of C. raciborskii varying from 102 to 106 cells·mL–1 of each strain for up to three hours. The cladocerans were then transferred to a medium without toxic filaments for 24 hours. Only the organisms exposed to the STX-producing strain showed signs of the immobilization of swimming movements, confirming the effects of the toxins. There was a linear correlation between the time required to induce stopping the swimming movement, with a shorter time to needed to induce immobilization at a higher the concentration; this correlation was inverse to the time required to recover the swimming movements (longer at higher concentrations, p < 0.1). D. laevis is a tropical and subtropical species with great potential for use in toxicity tests for the detection of STXs, despite being native to and found in a great array of freshwater bodies. This is the first assay testing STX-producing and non-producing C. raciborskii strains on D. laevis, species that are both found in Brazilian ecosystems.(AU)

Cylindrospermopsis raciborskii é uma espécie de cianobactéria, difundida mundialmente, conhecida como produtora de cianotoxinas. Algumas linhagens brasileiras são conhecidas como produtoras de saxitoxinas (STXs), as quais são classificadas como neurotoxinas e podem induzir a paralização dos movimentos natatórios em cladóceros. Daphnia laevis é um cladócero de ampla distribuição nas Américas e tem sido estudado como um organismo teste para uso em ensaios de toxicidade. Neste sentido, o presente trabalho avaliou os efeitos agudos de C. raciborskii, de uma cepa produtora de STXs (STX e neoSTX) - CYRF-01 e outra não produtora de cianotoxinas (NPCS-1) sobre a mobilidade de D. laevis. Para tanto, neonatas entre 6-24 horas de idade foram submetidas a concentrações de C. raciborskii variando de 102 a 106 céls.mL–1 de ambas as cepas, por um período de 3 horas, e transferidos posteriormente para um meio isento de filamentos tóxicos por 24horas. Apenas os organismos expostos à cepa produtora de STXs apresentaram paralisia dos movimentos natatórios, confirmando o efeito da cianotoxina. Houve uma correlação linear entre o tempo de paralização e as concentrações, isto é, nas concentrações mais altas, os organismos paralisaram num curto período de tempo, e conseqüentemente, levaram mais tempo para se recuperar (p < 0,1). D.laevis é uma espécie de região tropical e subtropical com potencial uso em bioensaios para detecção de STXs. Trata-se dos primeiros relatos acerca da resposta de D.laevis quando submetida às cepas de C. raciborskii produtora e não produtora de STXs, ambas isoladas de ecossistemas brasileiros.(AU)

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RESUMO

The potential of Gafanhoto Park as an American cutaneous leishmaniasis (ACL) focus was evaluated by examination of sand fly vectors of the Leishmania parasite. This forest remnant is located in a periurban area of Divin6polis, Brazil, where autochthonous cases of ACL have been reported. Sand fly populations were monitored over a 2-yr period (2006-2008) by using light traps (HP and Shannon). During systematic collections with HP traps, 824 specimens in total (342 males and 482 females) of 21 species were captured. Most prevalent species were as follows: Brumptomyia brumpti (Larrouse), Lutzomyia aragaoi (Costa Lima), Lutzomyia lutziana (Costa Lima), Lutzomyia sordellii (Shannon & Del Ponte), and Lutzomyia whitmani (Antunes & Coutinho). Using Shannon traps, 257 specimens representing 15 species were collected (159 females and 98 males), with a high prevalence of L. whitmani and Lutzomyia neivai (Pinto), both vectors of Leishmania braziliensis (Vianna). To ascertain the level of natural infection, a sample of females captured in Shannon traps was assayed for the presence of Leishmania by using polymerase chain reaction-restriction fragment length polymorphism, where 39% of insects were positive. The most infected species was L. whitmani (29 sand flies; 18.2%), followed by L. neivai (21; 13.2%), Lutzomyia christenseni (Young & Duncan) (five; 3.1%), Lutzomyia pessoai (Coutinho & Barreto) (three; 1.9%), L. aragaoi (one; 0.6%), Lutzomyia fischeri (Pinto) (one; 0.6%), Lutzomyia lenti (Mangabeira) (one; 0.6%), L. lutziana (one; 0.6%), and Lutzomyia monticula (Costa Lima) (one; 0.6%). The finding of potential and incriminated vectors naturally infected with Leishmania reinforces the need of epidemiologic surveillance in the area.

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RESUMO

OBJECTIVE: To analyse clinical and/or laboratorial preoperative hormonal dysfunction, of the nonpituitary intracranial lesions from midline and parasellar area. METHOD: Forty-four patients were evaluated with nonpituitary intracranial lesions, who had images studies (computed tomography or magnetic resonance) and preoperative basal hormonal level; 16 had preoperative hypothalamus-hypophysial function tests (megatests). These patients were divided in two groups. Group I - 34 lesions from midline: 11 craniopharyngiomas, 8 meningiomas, 3 germinomas, 3 tumors of sphenoid sinus, 2 empty sella syndrome, 2 pylocitic astrocytomas, 1 giant aneurysm, 2 mucoceles, 1 III ventricle diverticulum and 1 Rathke's cleft cyst; Group II - 10 lesions from parasellar area: 9 meningiomas and 1 giant aneurysm. RESULTS: In group I, 25/34 (73.5%) patients showed laboratorial hormonal deficit (14 without clinical manifestations) 18/34 (52.9%) hyperprolactinemia (5 with galactorreia) and 8 (53.3%) showed growth hormone deficiency in 15 megatests available in this group; 3 (8.8 %) patients presented central diabetes insipidus (CDI). In group II, 6/10 (60%) patients showed laboratorial hormonal deficit (5 without clinical manifestations), 1 (10%) hyperprolactinemia and 1 growth hormone deficiency (single megatest realized in this group); no patient had preoperative CID. CONCLUSIONS: The presence of nonspecific or poorly valorized clinical manifestations, does not indicate absence of hormonal dysfunction; in this present serie, 19/38 (50%) patients with laboratorial abnormalities, didn't show clinical manifestations. Hormonal dysfunction is frequent in sellar and perisellar nonpituitary lesions, specially involving midline.

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RESUMO

A great amount of heavy metals enter Pampulha Reservoir via it's main tributaries (Sarandi and Ressaca). Although no water quality classification has been carried out for these tributaries, the reservoir is expected to be in class 2 of the CONAMA-86 system. As part of a monitoring scheme of the Pampulha Watershed, heavy metals (Zn, Pb, Cd, Ni, Cu, Cr, Mn and Fe) were investigated in the water at a control site (considered free from direct human influence) and at potential sites of toxicity and contamination during August (dry season) and November (wet season) of 1998. The results for the first sampling period showed relatively high concentrations of zinc (0.22 mg.L-1) in the upper portion of the reservoir. The highest values of nickel and chromium (0.19 and 0.89 mg.L-1, respectively) were found in the initial portion of the Sarandi Stream, while the highest concentrations of lead (0.05 mg.L-1), cadmium (0.014 mg.L-1), manganese (0.43 mg.L-1) and iron (15.25 mg.L-1) were detected in the Ressaca Stream by the landfill dump of Belo Horizonte. A relatively high concentration of cadmium was also detected at the confluence of the two streams. During the second sampling period, there was an increase in the concentrations of zinc at all sampling sites except the control, with values varying from 0.71 mg.L-1 (the Sarandi Stream) to 2.50 mg.L-1 (the Ressaca Stream). Lead, cadmium, nickel and chromium concentrations were also higher in the Ressaca Stream, but not detected at the other sampling sites. Copper values were higher than in the first period: 0.10 mg.L-1 at the control up to 0.38 mg.L-1 at the confluence of the streams. Similar results were found for manganese and iron, with values reaching up to 19.30 and 125 mg.L-1, respectively. Moreover, all values recorded in the second sampling period were much higher than recommended for class 2 waters. These results emphasize the need for such monitoring in relation to better water quality management of this reservoir.

Assuntos

RESUMO

A great amount of heavy metals enter Pampulha Reservoir via it's main tributaries (Sarandi and Ressaca). Although no water quality classification has been carried out for these tributaries, the reservoir is expected to be in class 2 of the CONAMA-86 system. As part of a monitoring scheme of the Pampulha Watershed, heavy metals (Zn, Pb, Cd, Ni, Cu, Cr, Mn and Fe) were investigated in the water at a control site (considered free from direct human influence) and at potential sites of toxicity and contamination during August (dry season) and November (wet season) of 1998. The results for the first sampling period showed relatively high concentrations of zinc (0.22 mg.L-1) in the upper portion of the reservoir. The highest values of nickel and chromium (0.19 and 0.89 mg.L-1, respectively) were found in the initial portion of the Sarandi Stream, while the highest concentrations of lead (0.05 mg.L-1), cadmium (0.014 mg.L-1), manganese (0.43 mg.L-1) and iron (15.25 mg.L-1) were detected in the Ressaca Stream by the landfill dump of Belo Horizonte. A relatively high concentration of cadmium was also detected at the confluence of the two streams. During the second sampling period, there was an increase in the concentrations of zinc at all sampling sites except the control, with values varying from 0.71 mg.L-1 (the Sarandi Stream) to 2.50 mg.L-1 (the Ressaca Stream). Lead, cadmium, nickel and chromium concentrations were also higher in the Ressaca Stream, but not detected at the other sampling sites. Copper values were higher than in the first period: 0.10 mg.L-1 at the control up to 0.38 mg.L-1 at the confluence of the streams. Similar results were found for manganese and iron, with values reaching up to 19.30 and 125 mg.L-1, respectively. Moreover, all values recorded in the second sampling period were much higher than recommended for class 2 waters. These results emphasize the need for such monitoring in relation to better water quality management of this reservoir.

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RESUMO

The induction of protective immunity to Leishmania amazonensis was investigated by injection of parasite clones of low and medium virulence into susceptible mice. To this end, L. amazonensis were cloned by limiting dilution and the clones' virulence was evaluated by the course of infection in susceptible mice. Clones originally derived from the spleen showed virulence variations in comparison with that of the parental population (PP) of parasites. Two low-virulence clones (SP 5 and SP 20) and one medium-virulence clone (SP 11), representative of the spectrum of derived clones, were compared with virulent parasites and with an avirulent strain (Josefa) as to their ability to induce T-cell immune responses and to protect BALB/c mice from infection with the virulent L. amazonensis PP. Clone SP 20 and clone SP 11 induced partial protection when injected by the intravenous and intradermal route, respectively. The avirulent Josefa strain induced neither T-cell responses nor protection. Low-virulence L. amazonensis clones can therefore be additional tools in vaccine investigation.

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