Vitoria da Conquista, Brazil
Vitoria da Conquista, Brazil

Time filter

Source Type

da Silva-Castro M.M.,State University of Southwest Bahia
Phytotaxa | Year: 2017

Jacaranda heterophylla M.M.Silva-Castro, a new species of Jacaranda, is described and illustrated. This species is only known from a restricted area of Caatinga located between Lençóis and Palmeiras, at the Chapada Diamantina (Bahia, Brazil). It resembles J. grandifoliolata by the elliptic to obovate leaflets and J. jasminoides by the leaves that are pinnate at the base and bipinnate at the apex. However, J. heterophylla differs from J. grandifoliolata by the higher number of leaflets (17–19 vs. 3–5) and from J. jasminoides by the longer leaflets (6–15 cm vs. 1–4 cm). Information on its conservation status, distribution, and phenology are provided. © 2017 Magnolia Press.

Lemos V.A.,State University of Southwest Bahia | David G.T.,State University of Southwest Bahia
Microchemical Journal | Year: 2010

The development of an on-line preconcentration system with cloud point extraction for the determination of manganese is described. The system was used to determine manganese levels in food samples using flame atomic absorption spectrometry (FAAS). All steps of the cloud point extraction procedure were performed on-line, from the mixing of reagents to detection. The manganese ions are complexed in a mixture of the reagent 2-[2′-(6-methyl-benzothiazolylazo)]-4-bromophenol (Me-BTABr) and Triton X-114. The components are retained on a minicolumn and then desorbed with eluent acid to subsequent detection of manganese by FAAS. Under the optimized conditions, the method presented a detection limit of 0.7 μg L- 1 and an enrichment factor of 17 to a volume of 3000 μL. The sampling frequency was 30 h- 1. The accuracy of the method was tested by evaluating the amount of Mn in certified reference materials (apple leaves NIST 1515 and spinach leaves NIST 1570a). The proposed procedure was applied to food samples (shrimp powder, flaxseed flour, wheat flour, soy flour and oat), and the results agreed with those obtained by the determination of Mn in foods by atomic absorption spectrometry with electrothermal atomization (ETAAS). © 2009 Elsevier B.V. All rights reserved.

Lemos V.A.,State University of Southwest Bahia | Dos Santos L.O.,State University of Southwest Bahia
Food Chemistry | Year: 2014

The development of a method using solid phase extraction for preconcentration and determination of mercury by cold vapour atomic absorption spectrometry is described. Hg (II) ions are sorbed on a minicolumn packed with Amberlite XAD-4 sorbent functionalised with 2-(2′-benzothiazolylazo)-p- cresol (BTAC). Then, a reducing solution was used for desorption and the transport of the analyte for subsequent detection. The assay presented a limit of detection of 0.011 μg L-1 (0.011 μg g-1, for solid samples), a limit of quantification of 0.038 μg L-1 (0.038 μg g-1, for solid samples), a precision of 0.50% (1.000 μg L-1 Hg solution) and an enrichment factor of 46. The proposed method was applied to the determination of mercury in human saliva (0.055-0.200 μg L-1). The following seafood collected in Todos os Santos Bay, Brazil was also analysed: bass (0.169-0.195 μg g-1), mullet (0.043-0.361 μg g-1), shrimp (0.075-0.374 μg g-1) and mussel (0.206-0.397 μg g-1).© 2013 Elsevier Ltd. All rights reserved.

Cerqueira-Silva C.B.,State University of Southwest Bahia
Genetics and molecular research : GMR | Year: 2012

Little is known about the molecular genetic diversity of most Passiflora species. We used RAPD markers to evaluate the genetic diversity of 24 genotypes of the 'sleep' passion fruit (Passiflora setacea). Twelve primers generated 95 markers, 88% of which were polymorphic. The genetic distance estimated by the complement of the Dice index ranged from 0.29 (among accessions Ps-G1 and Ps-G13) to 0.69 (among accessions Ps-G21 and Ps-G23). Genotype grouping based on the UPGMA algorithm showed considerable variability among genotypes. We conclude that P. setacea has a broad genetic base that could be exploited in breeding programs.

Lemos V.A.,State University of Southwest Bahia | De Carvalho A.L.,State University of Southwest Bahia
Environmental Monitoring and Assessment | Year: 2010

The analysis of human biological samples, such as blood, urine, nails, and hair, is generally used for the verification of human exposure to toxic metals. In this review, various spectrometric methods for the determination of cadmium and lead in biological samples are discussed and compared. Several spectrometric techniques are presented and discussed with respect to various characteristics such as sensitivity, selectivity, and cost. Special attention is drawn to the procedures for digestion prior to the determination of cadmium and lead in hair, nails, blood, and urine. © 2009 Springer Science+Business Media B.V.

Cerqueira-Silva C.B.,State University of Southwest Bahia
Genetics and molecular research : GMR | Year: 2010

The genetic diversity and characteristics of commercial interest of Passiflora species make it useful to characterize wild germplasm, because of their potential use for fruit, ornamental and medicinal purposes. We evaluated genetic diversity, using RAPD markers, of 32 genotypes of Passiflora cincinnata collected from the wild in the region of Vitória da Conquista, Bahia, Brazil. Thirteen primers generated 95 polymorphic markers and only one monomorphic marker. The mean genetic distance between the genotypes estimated by the complement of the Dice index was 0.51 (ranging from 0.20-0.85), and genotype grouping based on the UPGMA algorithm showed wide variability among the genotypes. This type of information contributes to identification and conservation of the biodiversity of this species and for the identification of pairs of divergent individuals for maximum exploitation of existing variability.

Lima M.M.,State University of Southwest Bahia | Mariano-Neto E.,Federal University of Bahia
Forest Ecology and Management | Year: 2014

Despite the advances in scientific knowledge about causes and consequences of biodiversity loss, we still lack effective ways to incorporate this knowledge in the development of conservation policies. For example, several studies suggest a nonlinear decrease of species diversity in response to habitat loss at a landscape scale, predicting a threshold at which extinction rates increase dramatically. If this is true and we can find the threshold value with a safety margin, habitat cover is easily measured using GIS technics and can be incorporated into landscape occupation planning. This is particularly true in Neotropics where much of the occupation is founded or licensed by governmental agencies. This study aimed to investigate the thresholds in the relationship between the species richness of a particular plant family in the landscape and the percentage of forest cover on that landscape. Biological material was collected in 11 surveyed landscapes of 6. ×. 6. km randomly sampled from a large region of Brazilian Atlantic Forest from 11°80'S to 18°49'S and 40°08'W to 21°24'W in Bahia, Brazil. The landscape forest cover ranged from 5% to 60%, and in each landscape, eight 25. ×. 10. m plots were randomly established, the landscape's surveyed richness considered the entire set of eight plots. In each landscape we sampled trees with a circumference at breast height (CBH) above 8. cm belonging to Sapotaceae, a tree family that is severely threatened by human activities and generally composed of large, long-lived, animal-dispersed, shade-tolerant trees typical of the interior of forests. Those characteristics make them very representative of mature forest plant species. We evaluated whether a model with a breakpoint or a threshold was best for describing the relationship between richness and forest cover in the landscape using a model selection approach. The data were fitted to a generalized linear model, a piecewise model, and a logistic curve and evaluated using the Akaike information criterion (AIC). In all surveys, a total of 284 individuals belonging to 55 morphospecies were found, and several species are known to be very important in primate diet, which are also dispersers and even pollinators of some species. The best fitted model was the logistic model followed by the piecewise model, which confirms the nonlinearity of the relationship and the existence of a breakpoint. The value of the breakpoint was estimated at near 30% forest cover, and the data set revealed a very sharp decrease in richness and abundance. The value is close to other thresholds obtained in simulated and empirical studies, predicting a threshold between 10% and 30% of habitat in the landscape. Although many studies advocate a species-specific response to habitat loss and fragmentation, Sapotaceae as a whole experienced a dramatic decrease in richness in landscapes with reduced forest cover, most likely due to a common response to deleterious effects triggered by the reduction in habitat, and defaunation. Despite the fact that several processes occur during habitat reduction, such as fragmentation, isolation, increasing edge effects, and loss of key species, we obtained a strong signal of species reduction in response to habitat loss. The extensive sampling conducted and the scale used in this study, with regard to an important and representative group of plant species, reinforces the applicability of this type of study from the standpoint of policy strategies, to promote both species conservation and agricultural activities. © 2013 Elsevier B.V.

Dos Santos L.O.,State University of Southwest Bahia | Lemos V.A.,State University of Southwest Bahia
Water, Air, and Soil Pollution | Year: 2014

An on-line preconcentration system using solid-phase extraction with polytetrafluoroethylene was used for the determination of mercury by cold vapor atomic absorption spectrometry. The system uses electronically controlled valves and operates in two simple steps using sorption and elution. The Hg(II) ammonium pyrrolidinedithiocarbamate complexes are retained in a minicolumn packed with the sorbent. The elution, transportation, and reduction of the analyte ions are promoted by a solution of sodium tetrahydroborate(III). After optimization, the developed method showed the following analytical characteristics: a limit of detection of 0.02 μgL-1, linearity of 0.07 to 2.00 μgL-1, enrichment factor of 35, and sampling frequency of 27 h-1. The accuracy of the method was tested by analyzing the certified reference material BCR-060 Lagarosiphon major (aquatic plant). The proposed method was applied to the determination of mercury in water samples. © Springer International Publishing 2014.

Brito R.O.,State University of Southwest Bahia
Genetics and molecular research : GMR | Year: 2010

The order Thysanoptera is composed of cosmopolitan phytophagous and predaceous insects with diverse life histories, behaviors and habits. This order is currently thought to form a trichotomy with Hemiptera and Psocodea; Hemiptera and Thysanoptera are considered to be sister groups. The interrelationships within Thysanoptera remain unclear and cytotaxonomic studies are scarce in thrips. We report, for the first time, chromosomal data on seven species of thrips collected from a semi-arid region in the States of Bahia and Pernambuco (Northeast Brazil). A distinctive chromosomal pattern was observed in Thysanoptera when compared to other members within the infraclass Paraneoptera. Considerable karyotypic differences were also found within genera and species of Thysanoptera. Based on these data, we suggest that Paraneoptera forms a polyphyletic group and that Terebrantia and Tubulifera should be regarded as sister groups. The high chromosomal variability observed in Thysanoptera indicates that chromosomal rearrangements have played a key role in their speciation pathways.

Lemos V.A.,State University of Southwest Bahia | Vieira U.S.,State University of Southwest Bahia
Microchimica Acta | Year: 2013

We describe a method for single drop microextraction of manganese from fish, mollusk, and from natural waters using the reagent 1-(2-pyridylazo)-2-naphthol as the complexing agent and chloroform as the fluid extractor. After extraction, the analyte was directly submitted to graphite furnace electrothermal atomic absorption spectrometry. Once optimized, the method has a detection limit of 30 ng L-1, a limit of quantification of 100 ng L-1, and an enrichment factor of 16. Its accuracy was verified by applying the procedure to the following certified reference materials: apple leaves, spinach leaves, bovine liver, and mussel tissue. The procedure was also successfully applied to the determination of manganese in seafood and natural waters. © 2013 Springer-Verlag Wien.

Loading State University of Southwest Bahia collaborators
Loading State University of Southwest Bahia collaborators