Endemic to the Atlantic Forest of southeastern Brazil, buffy-headed (Callithrix flaviceps Thomas,... more Endemic to the Atlantic Forest of southeastern Brazil, buffy-headed (Callithrix flaviceps Thomas, 1903) and buffy-tufted-ear (Callithrix aurita E. Geoffroy, 1812) marmosets face harsh seasonal extremes of temperature and rainfall, together possibly the most severe ...
Scientific and public attention concerned with natural rubber (Hevea brasiliensis) production in ... more Scientific and public attention concerned with natural rubber (Hevea brasiliensis) production in the Amazon has focused on the high-tech practice of double-grafted, leaf blight resistant and high-yielding rubber clones on the one hand, and the low-tech practice of extractive use of natural rubber stands on the other. The intermediate, traditional practice of enriching slash-and-burn plots with rubber trees and managing them in a secondary forest environment, in association with other timber and non-timber species, has largely been overlooked. We present results from a survey of 51 farmer families conducted on the eastern bank of the Tapajós river in the central Brazilian Amazon, focusing on the population zone of the Tapajós National Forest and its northern vicinity. Actively managed rubber agroforests were most common on the sandy river banks and on humus-and clay-rich and ferralitic soils near the edge of the plateau at a few kilometers from the river. There was a gradient in management intensity between the proximity of the villages at the river, where rubber was often a component of homegardens, and the distant groves on the plateau, which often resembled secondary forests. The spatial separation of access to water at the river and more fertile soils on the plateau, the historical practice of abandoning the rubber groves at times of low rubber prices, and a substantial risk of losing plantations to abiotic and biotic threats, especially fire, are identified as factors that have presumably favored the development of agroforests with low management intensity in the region. Although about half of the interviewed farmers expressed a preference for weeded plantations, almost 90% of them extracted vegetal products other than rubber from the agroforests or used them as hunting grounds, and 80% believed that associated vegetation had no negative influence on rubber yields. The often good health of old rubber trees in Amazonian agroforests is explained with lower pressure from root rots, the periodic abandonment and especially a tapping technique that is well adapted to a moist forest environment.
Environmental monitoring and assessment, Jan 26, 2018
A study was conducted at three sampling regions along the Rio Negro and surrounding Puraquequara ... more A study was conducted at three sampling regions along the Rio Negro and surrounding Puraquequara Lake, Amazonas, Brazil. The aim was to determine the influence of the local effects of climatic and hydrological variables on new malaria cases. Data was gathered on the river level, precipitation, air temperature, and the number of new cases of autochthonous malaria between January 2003 and December 2013. Monthly averages, time series decompositions, cross-correlations, and multiple regressions revealed different relationships at each location. The sampling region in the upper Rio Negro indicated no statistically significant results. However, monthly averages suggest that precipitation and air temperature correlate positively with the occurrence of new cases of malaria. In the mid Rio Negro and Puraquequara Lake, the river level positively correlated, and temperature negatively correlated with new transmissions, while precipitation correlated negatively in the mid Rio Negro and positive...
... of Gagneux et al.(1997). Two microsatellite loci, Cj6 and Cj11, isolated in the common marmos... more ... of Gagneux et al.(1997). Two microsatellite loci, Cj6 and Cj11, isolated in the common marmoset, Callithrix jacchus, by Nievergelt (1998), were amplified using Polymerase Chain Reaction (PCR). The reactions took place in ...
... Photo by Stephen F. Ferrari. ... Abundance (sightings per 10 km surveyed) of while-fronted sp... more ... Photo by Stephen F. Ferrari. ... Abundance (sightings per 10 km surveyed) of while-fronted spider monkeys. Aleles marginatus (unshaded), and white-nosed bearded sakis, Chiropotes atbitiasux (shaded), at the four sites in study nucleus 3 on the Santarc'm-Cuiaba" Highway. ...
Congenital aplasia of the hallux (big toe) was observed in seven adult and infant members of a fr... more Congenital aplasia of the hallux (big toe) was observed in seven adult and infant members of a free-ranging group of silvery marmosets (Mico argentatus) in the Alter do Cha˜o savannah of central Amazonia. Apparently heritable, the condition was more common in males (80%) than females (50%) but was found in no other members of the population. Animals with the condition presented normal behaviour.
Field observations of predation are still relatively rare for most primate species, although a nu... more Field observations of predation are still relatively rare for most primate species, although a number of reports are now available for the marmosets and tamarins (eg MOYNIHAN, 1970; EMMONS, 1987; HEYMANN, 1987), whose principal predators appear to be raptors and ...
Liposomes composed of cationic lipids and neutral phospholipids have been used as vehicles for ce... more Liposomes composed of cationic lipids and neutral phospholipids have been used as vehicles for cellular delivery of DNA and drug delivery. The aim of this study is to get a better understanding of phospholipid-cationic lipid interactions that is essential for the development of this potential. We have studied the interaction between cationic lipid liposomes primarily composed of dioctadecyldimethylammonium bromide (DODAB) with two different phospholipids, dioleoyl phosphatidylethanolamine (DOPE) and soybean phosphatidylcholine (PC), as well as with cholesterol. The effect of these components on the liposome's physical properties (microviscosity and polarity) was accessed by studying, both the steady-state and time-resolved, fluorescence anisotropy of the dye Nile Red. This information combined with analysis of the steady-state emission and fluorescence lifetime of Nile Red using the different lipids and cholesterol provided information concerning the polarity and hydration level changes in these vesicle systems along with organisational information.
DESCRIPTION Contribution to the 3rd International Research universities Network (IRUN). Symposium... more DESCRIPTION Contribution to the 3rd International Research universities Network (IRUN). Symposium on Nanotechnology October 14-15 Barcelona 2010
DESCRIPTION Ni NPs were obtained by wet chemical solution method and their size was controlled us... more DESCRIPTION Ni NPs were obtained by wet chemical solution method and their size was controlled using a non-ionic surfactant. Combining high-angle annular dark field (HAADF) and electron energy loss spectroscopy (EELS), the nickel oxide layer was identified as not continuous and with non homogenous thickness.
Nickel ferrite nanoparticles with superparamagnetic behavior at room temperature were synthesized... more Nickel ferrite nanoparticles with superparamagnetic behavior at room temperature were synthesized using a coprecipitation method. These magnetic nanoparticles were either covered with a lipid bilayer, forming dry magnetic liposomes (DMLs), or entrapped in liposomes, originating aqueous magnetoliposomes (AMLs). A new and promising method for the synthesis of DMLs is described. The presence of the lipid bilayer in DMLs was confirmed by FRET (Förster Resonance Energy Transfer) measurements between the fluorescent-labeled lipids NBD-C12-HPC (NBD acting as a donor) included in the second lipid layer and rhodamine B-DOPE (acceptor) in the first lipid layer. An average donor-acceptor distance of 3 nm was estimated. Assays of the non-specific interactions of magnetoliposomes with biological membranes (modeled using giant unilamellar vesicles, GUVs) were performed. Membrane fusion between both aqueous and dry magnetoliposomes and GUVs was confirmed by FRET, which is an important result regarding applications of these systems both as hyperthermia agents and antitumor drug nanocarriers.
This research describes the processing using GIS with the data of the National Hidrometereologic ... more This research describes the processing using GIS with the data of the National Hidrometereologic Net managed by Brazilian Electricity Regulatory Agency - Aneel. The manipulation refers to an attempt, in a first step, of modeling the suspending solid discharges dynamics in the main Brazilian rivers with geo-statistical contour method TIN (Triangules Irregular Net of Delaunay).
Dioctadecyldimethylammonium bromide (DODAB):1-monooleoyl-rac-glycerol (MO) cationic liposomes wer... more Dioctadecyldimethylammonium bromide (DODAB):1-monooleoyl-rac-glycerol (MO) cationic liposomes were reported as a promising alternative to common transfection agents, showing superior effectiveness on the transfection of the 293 T mammalian cell line with pSV-β-gal plasmid DNA. The study of DODAB:MO aggregates in the absence of DNA has indicated that their morphology depends on the balance between DODAB's tendency to form bilayer structures and MO's propensity to form inverted non-lamellar structures with cubic organization. Other parameters, such as the temperature have proved to be crucial in the definition of the morphology of the developed nanocarrier. Therefore, in this work, a step forward to the current gene carrier system will be given by studying the effect of the tunable parameters (incubation temperature and MO content) on the structure of pDNA:DODAB:MO lipoplexes. More importantly, the implications that these tunable parameters could have in terms of lipoplex tran...
Neste estudo, fazemos uma caracterização dos fluxos de cargas de exportação e importação dentro d... more Neste estudo, fazemos uma caracterização dos fluxos de cargas de exportação e importação dentro do território Brasileiro em direção ou originários dos portos brasileiros. A partir desses fluxos, é possível levantar indicadores de concorrência entre portos, considerando-se diferentes tipos de carga. Além dos indicadores apresentados, este estudo traz uma discussão sobre escalas mínimas eficientes para as operações portuárias. Essa discussão é importante para a regulação no setor, uma vez que portos atendendo a áreas com baixa produção ou demanda podem comportar apenas um terminal em operação. De maneira geral, observou-se que o fator geográfico é um dos aspectos mais importantes para a escolha dos agentes em relação a que porto utilizar para exportar ou importar os seus produtos. Nas unidades da federação na costa brasileira, os indicadores de concorrência evidenciam uma maior concentração justamente nos portos localizados nesses estados, ou em estados vizinhos. Para exportadores ou importadores localizados em estados no interior do país, os indicadores de concentração sugerem uma maior diversificação dos portos utilizados. Essa importância observada para o aspecto geográfico pode estar relacionada diretamente aos custos de transportes internos e ao seu peso sobre o valor total da logística de exportação ou importação.
Neste estudo, apresentamos modelos para analisar os impactos dos custos logísticos de transporte ... more Neste estudo, apresentamos modelos para analisar os impactos dos custos logísticos de transporte sobre a decisão de que porto utilizar para exportações ou importações de cargas no Brasil. Para isso, emprega-se uma técnica baseada em distribuições de repartição fracional (fractional split-distribution model), para a qual a variável resposta é a participação dos portos nas cargas exportadas ou importadas por uma determinada microrregião. A estimação dos parâmetros do modelo é feita via maximização da função e quasi-verossimilhança, utilizandose informações de comércio exterior brasileiro. Confirmando o que foi observado em outros estudos, o fator geográfico se mostrou muito importante para a escolha dos agentes em relação a que porto utilizar para exportar ou importar os seus produtos. Com base nos modelos estimados, é possível simular potenciais impactos de diferentes cenários de alterações nos custos de transportes sobre a concorrência entre portos, nos mercados geográficos brasileiros. A partir dos resultados das simulações, o estudo traz uma análise qualitativa sobre potenciais impactos de diversos projetos atuais de melhorias nas malhas ferroviárias e rodoviárias, em termos de concorrência no setor portuário brasileiro.
It is reported the fluorescence and absorption spectra of pure cationic and neutral forms of benz... more It is reported the fluorescence and absorption spectra of pure cationic and neutral forms of benzo[a]phenoxazine derivatives containing different functional groups at 5-and 9-positions obtained by shifting the acid-base equilibria with the addition of a strong acid or base. The photophysical behavior of these compounds in AOT/cyclohexane/water w/o microemulsions as a function of water content is also investigated.
The objective of our work has been the microencapsulation of dyes with lecithin from soybean, wit... more The objective of our work has been the microencapsulation of dyes with lecithin from soybean, with the formation of liposomes, as a substitute for synthetic auxiliaries so as to improve the quality of the effluent. Current scenarios promote the disintegration and leakage of the liposomes, such as, changes in temperature, pH, and the use of surfactants. Since dyeing process is a mix of all these parameters, we pretended to study each one separately. Changes in pH at constant temperature induce a release of dye similar with changes in temperature. In acid conditions, we found a very fast initial dye release which doesn't occur in basic conditions. Using carboxyfluorescein, as a pH fluorescence probe, we concluded that the liposome membrane doesn't protect the liposome interior from changes on the external pH.
Endemic to the Atlantic Forest of southeastern Brazil, buffy-headed (Callithrix flaviceps Thomas,... more Endemic to the Atlantic Forest of southeastern Brazil, buffy-headed (Callithrix flaviceps Thomas, 1903) and buffy-tufted-ear (Callithrix aurita E. Geoffroy, 1812) marmosets face harsh seasonal extremes of temperature and rainfall, together possibly the most severe ...
Scientific and public attention concerned with natural rubber (Hevea brasiliensis) production in ... more Scientific and public attention concerned with natural rubber (Hevea brasiliensis) production in the Amazon has focused on the high-tech practice of double-grafted, leaf blight resistant and high-yielding rubber clones on the one hand, and the low-tech practice of extractive use of natural rubber stands on the other. The intermediate, traditional practice of enriching slash-and-burn plots with rubber trees and managing them in a secondary forest environment, in association with other timber and non-timber species, has largely been overlooked. We present results from a survey of 51 farmer families conducted on the eastern bank of the Tapajós river in the central Brazilian Amazon, focusing on the population zone of the Tapajós National Forest and its northern vicinity. Actively managed rubber agroforests were most common on the sandy river banks and on humus-and clay-rich and ferralitic soils near the edge of the plateau at a few kilometers from the river. There was a gradient in management intensity between the proximity of the villages at the river, where rubber was often a component of homegardens, and the distant groves on the plateau, which often resembled secondary forests. The spatial separation of access to water at the river and more fertile soils on the plateau, the historical practice of abandoning the rubber groves at times of low rubber prices, and a substantial risk of losing plantations to abiotic and biotic threats, especially fire, are identified as factors that have presumably favored the development of agroforests with low management intensity in the region. Although about half of the interviewed farmers expressed a preference for weeded plantations, almost 90% of them extracted vegetal products other than rubber from the agroforests or used them as hunting grounds, and 80% believed that associated vegetation had no negative influence on rubber yields. The often good health of old rubber trees in Amazonian agroforests is explained with lower pressure from root rots, the periodic abandonment and especially a tapping technique that is well adapted to a moist forest environment.
Environmental monitoring and assessment, Jan 26, 2018
A study was conducted at three sampling regions along the Rio Negro and surrounding Puraquequara ... more A study was conducted at three sampling regions along the Rio Negro and surrounding Puraquequara Lake, Amazonas, Brazil. The aim was to determine the influence of the local effects of climatic and hydrological variables on new malaria cases. Data was gathered on the river level, precipitation, air temperature, and the number of new cases of autochthonous malaria between January 2003 and December 2013. Monthly averages, time series decompositions, cross-correlations, and multiple regressions revealed different relationships at each location. The sampling region in the upper Rio Negro indicated no statistically significant results. However, monthly averages suggest that precipitation and air temperature correlate positively with the occurrence of new cases of malaria. In the mid Rio Negro and Puraquequara Lake, the river level positively correlated, and temperature negatively correlated with new transmissions, while precipitation correlated negatively in the mid Rio Negro and positive...
... of Gagneux et al.(1997). Two microsatellite loci, Cj6 and Cj11, isolated in the common marmos... more ... of Gagneux et al.(1997). Two microsatellite loci, Cj6 and Cj11, isolated in the common marmoset, Callithrix jacchus, by Nievergelt (1998), were amplified using Polymerase Chain Reaction (PCR). The reactions took place in ...
... Photo by Stephen F. Ferrari. ... Abundance (sightings per 10 km surveyed) of while-fronted sp... more ... Photo by Stephen F. Ferrari. ... Abundance (sightings per 10 km surveyed) of while-fronted spider monkeys. Aleles marginatus (unshaded), and white-nosed bearded sakis, Chiropotes atbitiasux (shaded), at the four sites in study nucleus 3 on the Santarc'm-Cuiaba" Highway. ...
Congenital aplasia of the hallux (big toe) was observed in seven adult and infant members of a fr... more Congenital aplasia of the hallux (big toe) was observed in seven adult and infant members of a free-ranging group of silvery marmosets (Mico argentatus) in the Alter do Cha˜o savannah of central Amazonia. Apparently heritable, the condition was more common in males (80%) than females (50%) but was found in no other members of the population. Animals with the condition presented normal behaviour.
Field observations of predation are still relatively rare for most primate species, although a nu... more Field observations of predation are still relatively rare for most primate species, although a number of reports are now available for the marmosets and tamarins (eg MOYNIHAN, 1970; EMMONS, 1987; HEYMANN, 1987), whose principal predators appear to be raptors and ...
Liposomes composed of cationic lipids and neutral phospholipids have been used as vehicles for ce... more Liposomes composed of cationic lipids and neutral phospholipids have been used as vehicles for cellular delivery of DNA and drug delivery. The aim of this study is to get a better understanding of phospholipid-cationic lipid interactions that is essential for the development of this potential. We have studied the interaction between cationic lipid liposomes primarily composed of dioctadecyldimethylammonium bromide (DODAB) with two different phospholipids, dioleoyl phosphatidylethanolamine (DOPE) and soybean phosphatidylcholine (PC), as well as with cholesterol. The effect of these components on the liposome's physical properties (microviscosity and polarity) was accessed by studying, both the steady-state and time-resolved, fluorescence anisotropy of the dye Nile Red. This information combined with analysis of the steady-state emission and fluorescence lifetime of Nile Red using the different lipids and cholesterol provided information concerning the polarity and hydration level changes in these vesicle systems along with organisational information.
DESCRIPTION Contribution to the 3rd International Research universities Network (IRUN). Symposium... more DESCRIPTION Contribution to the 3rd International Research universities Network (IRUN). Symposium on Nanotechnology October 14-15 Barcelona 2010
DESCRIPTION Ni NPs were obtained by wet chemical solution method and their size was controlled us... more DESCRIPTION Ni NPs were obtained by wet chemical solution method and their size was controlled using a non-ionic surfactant. Combining high-angle annular dark field (HAADF) and electron energy loss spectroscopy (EELS), the nickel oxide layer was identified as not continuous and with non homogenous thickness.
Nickel ferrite nanoparticles with superparamagnetic behavior at room temperature were synthesized... more Nickel ferrite nanoparticles with superparamagnetic behavior at room temperature were synthesized using a coprecipitation method. These magnetic nanoparticles were either covered with a lipid bilayer, forming dry magnetic liposomes (DMLs), or entrapped in liposomes, originating aqueous magnetoliposomes (AMLs). A new and promising method for the synthesis of DMLs is described. The presence of the lipid bilayer in DMLs was confirmed by FRET (Förster Resonance Energy Transfer) measurements between the fluorescent-labeled lipids NBD-C12-HPC (NBD acting as a donor) included in the second lipid layer and rhodamine B-DOPE (acceptor) in the first lipid layer. An average donor-acceptor distance of 3 nm was estimated. Assays of the non-specific interactions of magnetoliposomes with biological membranes (modeled using giant unilamellar vesicles, GUVs) were performed. Membrane fusion between both aqueous and dry magnetoliposomes and GUVs was confirmed by FRET, which is an important result regarding applications of these systems both as hyperthermia agents and antitumor drug nanocarriers.
This research describes the processing using GIS with the data of the National Hidrometereologic ... more This research describes the processing using GIS with the data of the National Hidrometereologic Net managed by Brazilian Electricity Regulatory Agency - Aneel. The manipulation refers to an attempt, in a first step, of modeling the suspending solid discharges dynamics in the main Brazilian rivers with geo-statistical contour method TIN (Triangules Irregular Net of Delaunay).
Dioctadecyldimethylammonium bromide (DODAB):1-monooleoyl-rac-glycerol (MO) cationic liposomes wer... more Dioctadecyldimethylammonium bromide (DODAB):1-monooleoyl-rac-glycerol (MO) cationic liposomes were reported as a promising alternative to common transfection agents, showing superior effectiveness on the transfection of the 293 T mammalian cell line with pSV-β-gal plasmid DNA. The study of DODAB:MO aggregates in the absence of DNA has indicated that their morphology depends on the balance between DODAB's tendency to form bilayer structures and MO's propensity to form inverted non-lamellar structures with cubic organization. Other parameters, such as the temperature have proved to be crucial in the definition of the morphology of the developed nanocarrier. Therefore, in this work, a step forward to the current gene carrier system will be given by studying the effect of the tunable parameters (incubation temperature and MO content) on the structure of pDNA:DODAB:MO lipoplexes. More importantly, the implications that these tunable parameters could have in terms of lipoplex tran...
Neste estudo, fazemos uma caracterização dos fluxos de cargas de exportação e importação dentro d... more Neste estudo, fazemos uma caracterização dos fluxos de cargas de exportação e importação dentro do território Brasileiro em direção ou originários dos portos brasileiros. A partir desses fluxos, é possível levantar indicadores de concorrência entre portos, considerando-se diferentes tipos de carga. Além dos indicadores apresentados, este estudo traz uma discussão sobre escalas mínimas eficientes para as operações portuárias. Essa discussão é importante para a regulação no setor, uma vez que portos atendendo a áreas com baixa produção ou demanda podem comportar apenas um terminal em operação. De maneira geral, observou-se que o fator geográfico é um dos aspectos mais importantes para a escolha dos agentes em relação a que porto utilizar para exportar ou importar os seus produtos. Nas unidades da federação na costa brasileira, os indicadores de concorrência evidenciam uma maior concentração justamente nos portos localizados nesses estados, ou em estados vizinhos. Para exportadores ou importadores localizados em estados no interior do país, os indicadores de concentração sugerem uma maior diversificação dos portos utilizados. Essa importância observada para o aspecto geográfico pode estar relacionada diretamente aos custos de transportes internos e ao seu peso sobre o valor total da logística de exportação ou importação.
Neste estudo, apresentamos modelos para analisar os impactos dos custos logísticos de transporte ... more Neste estudo, apresentamos modelos para analisar os impactos dos custos logísticos de transporte sobre a decisão de que porto utilizar para exportações ou importações de cargas no Brasil. Para isso, emprega-se uma técnica baseada em distribuições de repartição fracional (fractional split-distribution model), para a qual a variável resposta é a participação dos portos nas cargas exportadas ou importadas por uma determinada microrregião. A estimação dos parâmetros do modelo é feita via maximização da função e quasi-verossimilhança, utilizandose informações de comércio exterior brasileiro. Confirmando o que foi observado em outros estudos, o fator geográfico se mostrou muito importante para a escolha dos agentes em relação a que porto utilizar para exportar ou importar os seus produtos. Com base nos modelos estimados, é possível simular potenciais impactos de diferentes cenários de alterações nos custos de transportes sobre a concorrência entre portos, nos mercados geográficos brasileiros. A partir dos resultados das simulações, o estudo traz uma análise qualitativa sobre potenciais impactos de diversos projetos atuais de melhorias nas malhas ferroviárias e rodoviárias, em termos de concorrência no setor portuário brasileiro.
It is reported the fluorescence and absorption spectra of pure cationic and neutral forms of benz... more It is reported the fluorescence and absorption spectra of pure cationic and neutral forms of benzo[a]phenoxazine derivatives containing different functional groups at 5-and 9-positions obtained by shifting the acid-base equilibria with the addition of a strong acid or base. The photophysical behavior of these compounds in AOT/cyclohexane/water w/o microemulsions as a function of water content is also investigated.
The objective of our work has been the microencapsulation of dyes with lecithin from soybean, wit... more The objective of our work has been the microencapsulation of dyes with lecithin from soybean, with the formation of liposomes, as a substitute for synthetic auxiliaries so as to improve the quality of the effluent. Current scenarios promote the disintegration and leakage of the liposomes, such as, changes in temperature, pH, and the use of surfactants. Since dyeing process is a mix of all these parameters, we pretended to study each one separately. Changes in pH at constant temperature induce a release of dye similar with changes in temperature. In acid conditions, we found a very fast initial dye release which doesn't occur in basic conditions. Using carboxyfluorescein, as a pH fluorescence probe, we concluded that the liposome membrane doesn't protect the liposome interior from changes on the external pH.
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