bluuebunny/crossref_metadata_2025 huggingface dataset:
Ureotelism is inducible in the neotropical freshwater Hoplias malabaricus (Teleostei, Erythrinidae)
Authors: Moraes G. , Polez V. L. P.
Published: April 2005

Increased environmental pH decreases ammonia transport through the gills, impairing nitrogenous waste. The consequent toxicity is usually drastic to most fishes. A few species are able to synthesize urea as a way to detoxify plasma ammonia. We studied three teleosts of the family Erythrinidae living in distinct environments, and assumed the biochemical behaviors would be different in spite of their being closely related species. Adult fish collected in the wild were submitted to alkaline water and the urea excretion rate was determined. The specific activity of urea cycle enzymes was determined in liver samples of fish from neutral waters. The studied species Hoplias lacerdae, Hoplerithrynus unitaeniatus, and Hoplias malabaricus are ureogenic. Urea synthesis is not a metabolic way to detoxify ammonia in H. lacerdae and Hoplerithrynus unitaeniatus exposed to an alkaline environment. The plasma ammonia profile of both species showed two distinct biochemical responses. Urea excretion of H. malabaricus was high in alkaline water, and the transition to ureotelism is proposed. The nitrogen excretion rate of H. malabaricus was among the highest values reported and the high urea excretion leads us to include this species as ureotelic in alkaline water.
Differentiation and genetic variability in natural populations of Anopheles (N.) triannulatus (Neiva& Pinto, 1922) of Brazilian Amazonia
Authors: Santos J. M. M. , Maia J. F. , Tadei W. P.
Published: April 2005

Populations of Anopheles triannulatus from Macapá (AP), Aripuanã (MT), Ji-Paraná (RO), and Manaus-Janauari Lake (AM) were studied using 16 enzymatic loci. The results of the isozyme analysis showed that the population of Macapá presented higher polymorphism (56.3%). The lowest variability was observed in the population of Manaus (p = 25.0; Ho = 0.077 ± 0.046). The results of Wright's F statistics showed unbalance due to excess of homozygotes (Fis > Fst), denoting a certain intrapopulational differentiation. Although the populations are genetically very close (D = 0.003 - 0.052), the dendrogram separates the populations in two groups: Macapá separated from that of Manaus, Ji-Paraná, and Aripuanã. This result may suggest a reduction in the genic flow, which possibly had some influence in the substructuration of the populations.
Seasonality of the activity pattern of Callithrix penicillata (Primates, Callitrichidae) in the cerrado (scrub savanna vegetation)
Authors: Vilela S. L. , Faria D. S. de
Published: April 2005

Two wild groups of Callithrix penicillata, the Black Pincelled Marmoset, were observed from January to September 1998, in two areas, one an area of dense scrub savanna vegetation (cerrado) and the other, a semidecidual woodland (cerradão), both within the boundaries of the Ecological Reserve of IBGE (Brazilian Institute of Geography and Statistics), in an environmentally protected area, the APA (Portuguese abbreviation for "environmental protected area") Gama/Cabeça-de-Veado, Brasília, DF. The behavioral data collected during the rainy (January 15 to April 15) and dry season (June 1 to September 15) were compared. Because of the proximity to the Reserve facilities, the group from the dense scrub savanna vegetation (CD) was submitted to antropic impacts different from the group in the semidecidual woodland (CE), which was using as territory an area that had been suffering from man-made fires every two years as part of a long-term experimental project on fire impacts. The behavioral data was quantified by instantaneous cross-section ("scan sampling") every ten minutes with records of locomotion, rest, foraging for insects, use of exudate, and feeding. During the whole year, the greatest percentage of time spent by CE and CD was in foraging for insects, with 44% and 39%, respectively. It was evident when comparing the data for the two seasons that, for both groups, foraging for insects was more intense during the dry season, possibly to complement the shortage of food, and locomotion increased during the rainy season. The greater the availability and distribution of fruit in the areas, the greater the locomotion of the groups to obtain these resources. None of the other behavioral patterns, including the use of exudates, presented significant differences between the two seasons. Both groups foraged more frequently during the dry season and locomoted more during the rainy one.
Fecundity and fertility of Macrobrachium amazonicum (Crustacea, Palaemonidae)
Authors: da Silva R. R. , Sampaio C. M. S. , Santos J. A.
Published: April 2005

In Brazil, studies with native freshwater prawn species were discontinued due to great importance of Macrobrachium rosenbergii. Therefore, it is necessary to continue investigations about our species, in order to develop technology adequate to our reality and in a future allow prawn farmers to culture other species. The aim of this study was to determine the fecundity and fertility of Macrobrachium amazonicum captured monthly from June 1999 to June 2001 from Jaguaribe River, Itaiçaba, Ceará, Brazil. Prawns were collected using fishing net and transferred at Biological Science Laboratory, Ceará State University (Fortaleza, Ceará, Brazil). Among the ovigerous M. amazonicum females, 60 were randomly selected to determine fecundity. The eggs adhered to the pleopods were taken out and they were then placed in a Gilson solution, and then stored in alcohol 70%. Individual fecundity was determined from the total egg counting, using a stereoscopic microscope. To determine fertility, ovigerous M. amazonicum females were stored in individual 10 L-glass tanks maintained under strong aeration. After the hatching, the larvae were siphoned and counted. The data referring to total length and weight of all the females, storage date, coloration and number of eggs, weight and coloration of gonad and number of hatched larvae were noted. With respect to average fecundity (F) by length classes, the lowest and highest number of eggs observed was 696 and 1,554, respectively. As for fecundity by weight classes, the lowest number of eggs observed was 760 and the highest, 1,690. The highest number of eggs observed individually per hatching was 2,193. Average fecundity/total length (L) and average fecundity/total weight (W) may be expressed by a linear relationship. The adjusted equations are: F = -411.6 + 203.1 L (p < 0.0001) and F = 566.4 + 157.3 W (p < 0.0001), respectively. In the analysis of average fertility (N) per length classes, the lowest and highest number of larvae observed was 374 and 1,301, respectively. With respect to fertility per weight classes, the lowest number of larvae was 581 and the highest, 1,391. In this work, the maximum number of larvae observed per hatching for females kept in laboratory was 2,594. Average fertility/total length and average fertility/total weight may be expressed by a linear relationship. The adjusted equations are: N = -1042.7 + 264.9 L (p < 0.0002); N = 384.1 + 160.3 W (p < 0.003). From these results we can deduced that fecundity and fertility of M. amazonicum are lower than ones commercial species, nevertheless it can be captured during all year long. The number of captured prawns was large in the months whose level of water was low; the inverse was observed in the months that the river was with a high volume of water.
Fish diversity of floodplain lakes on the lower stretch of the Solimões River
Authors: Siqueira-Souza F. K. , Freitas C. E. C.
Published: April 2005

The fish community of the Solimões floodplain lakes was studied by bimonthly samples taken from May 2001 to April 2002. These were carried out at lakes Maracá (03º51'33"S, 62º35'08,6"W), Samaúma (03º50'42,1"S, 61º39'49,3"W), and Sumaúma and Sacambú (03º17'11,6"S and 60º04'31,4"W), located between the town of Coari and the confluence of the Solimões and Negro rivers. Collections were done with 15 gillnets of standardized dimensions with several mesh sizes. We collected 1,313 animals distributed in 77 species, belonging to 55 genera of 20 families and 5 orders. Characiformes was the most abundant Order, with a larger number of representatives in the Serrasalmidae and Curimatidae. The most abundant species in the samplings were Psectrogaster rutiloides (132 individuals), Pigocentrus nattereri (115 individuals), and Serrasalmus elongatus (109 individuals). Lakes Samaúma, Sacambú, and Sumaúma were adjusted to logarithmic and lognormal series. The diversity exhibited an inverse gradient to the river flow, showing the highest diversity at Lake Sumaúma, followed by Samaúma, Sacambú, and Maracá. Species richness estimated through the jackknife technique ranged from 78 to 107 species.
Community ecology of metazoan parasites of the later juvenile common snook Centropomus undecimalis (Osteichthyes: Centropomidae) from the coastal zone of the state of Rio de Janeiro, Brazil
Authors: Tavares L. E. R. , Luque J. L.
Published: April 2005

Between April and December 2000, seventy-nine specimens of Centropomus undecimalis from Angra dos Reis, coastal zone of the State of Rio de Janeiro (23º01'S, 44º19'W), Brazil, were necropsied to study their infracommunities of metazoan parasites. Nine species of metazoan parasites were collected: 1 digenean, 1 monogenean, 1 acantocephalan, 1 nematode, 4 copepods, and 1 isopod, and 96.2% of the fishes were parasitized by one or more metazoan, with mean of 85.3 ± 122.9 parasite/fish. The digenean Acanthocollaritrema umbilicatum Travassos, Freitas & Bührnheim represented the majority of the parasites specimens collected, totaling, 94.7%. This species was the most abundant, prevalent, and dominant, showing positive correlation with the host's total body length and parasite abundance. The copepod species Acantholochus unisagittatus Tavares & Luque presented differences in abundance in relation to sex of host. The mean diversity in the infracommunities of C. undecimalis was H = 0.095 ± 0.116, with no correlation with the host's total body length but correlated with the host's sex. No pair of parasite species showed positive or negative association or covariation. The dominance of digenean A. umbilicatum in the later juvenile common snook parasite community could be related with the predatory food habits of common snook and an apparent feeding transition period which might occasion great exposure to infective forms.
Body size and flight distance in stingless bees (Hymenoptera: Meliponini): inference of flight range and possible ecological implications
Authors: Araújo E. D. , Costa M. , Chaud-Netto J. , Fowler H. G.
Published: April 2005

We examined the spatial implications of maximum flight distance for several species of stingless bees. Data suggested that maximum flight distance in Meliponini is a function of body size, especially generalized wing size, which can be estimated through principal component analysis. For six species of stingless bees, flight distances and generalized wing sizes were highly correlated (r = 0.938). This indicates that species of Meliponini occupy an effectively larger area as body size increases, which has important implications in the spatial dynamics of local populations restricted to forest fragments. We also used the fitted linear regression model to estimate the maximum flight distance for 12 other species of Meliponini. The results of this research may provide insights for future studies of biological conservation.
The larval midgut of Anticarsia gemmatalis (Hübner) (Lepidoptera: Noctuidae): light and electron microscopy studies of the epithelial cells
Authors: Levy S. M. , Falleiros A. M. F. , Gregório E. A. , Arrebola N. R. , Toledo L. A.
Published: April 2005

The morphology of the midgut epithelium cells of Anticarsia gemmatalis (Hübner) larvae is described by light and transmission electron microscopy. The midgut of A. gemmatalis is the largest portion of the digestive tract, with three distinct regions: proximal, media and distal. Its wall is formed by pseudostratified columnar epithelial tissue having four cell types: columnar, goblet, regenerative, and endocrine cells. The columnar cells are numerous and long, with the apical portion showing many lengthy microvilli and the basal portion invaginations forming a basal labyrinth. The goblet cells have a large goblet-shaped central cavity delimited by cytoplasmic projections filled with mitochondria. The regenerative cells present electron-dense cytoplasm and few organelles. The endocrine cells are characterized by electron-dense secretory granules, usually concentrated in the cytoplasm basal region.
Populational genetic structure of free-living maned wolves (Chrysocyon brachyurus) determined by proteic markers
Authors: De Mattos P. S. R. , Del Lama M. A. , Toppa R. H. , Arno Rudi Schwantes A. R.
Published: April 2005

Electrophoretic analysis of presumptive twenty gene loci products was conducted in hemolisates and plasma samples of twenty-eight maned wolves (Chrysocyon brachyurus) from an area in northeastern São Paulo State, Brazil. The area sampled was divided into three sub-areas, with the Mogi-Guaçu and Pardo rivers regarded as barriers to the gene flow. The polymorphism degree and heterozygosity level (intralocus and average) estimated in this study were similar to those detected by other authors for maned wolves and other species of wild free-living canids. The samples of each sub-area and the total sample exhibited genotype frequencies consistent with the genetic equilibrium model. The values of the F-statistics evidenced absence of inbreeding and population subdivision and, consequently, low genetic distances were found among the samples of each area.
Functional groups of forest succession as dissipative structures: an applied study
Authors: Souza G. M. , Ribeiro R. V. , Santos M. G. , Ribeiro H. L. , Oliveira R. F.
Published: April 2005

This study tested the hypothesis that dissipative efficiency of tropical tree species could be an ecological advantage in the forest succession process. Daily leaf gas exchanges of a pioneer species (Guazuma ulmifolia) and a late successional species (Cariniana legalis) were evaluated under well-irrigated conditions and by withholding irrigation. Analyses of network connectance (Cg) and plant autonomy (At) were carried out in order to assess metabolic network changes in response to environmental perturbation. As a global estimation of latent heat dissipation, the capacity to both maintain and cool leaf temperature in response to air temperature changes (deltaT = TºCair - TºCleaf) was evaluated. The changes observed in both the systemic parameters (Cg and At) and the physiological ones brought about by water deficit, associated with discrepant growth rates between both species, suggested that the initial formation of gap canopies composed by pioneer species could simply be a result of the higher photosynthetic rates of these species, and not necessarily because late successional species cannot cope with such a heterogeneous environment as that of a gap. Our results indicate that, in the absence of water constraints, the highest CO2 assimilation rates of pioneer species are supported by the efficiency of the whole dissipative structure, involving both degradation and dissipative processes. As a practical result, our study suggests the deltaT analysis in order to evaluate the efficiency of dissipative structures and as a aid in characterizing functional groups.
Electroantennography in the study of two stingless bee species (Hymenoptera: meliponini)
Authors: Patricio E. F. L. R. A. , Cruz-López L. , Morgan E. D.
Published: April 2005

The first recorded electroantennographic preliminary studies on stingless bees have been performed using two species of Frieseomelitta from Brazil. Experiments with F. silvestrii and F. varia showed that antennae respond to hexane extracts of heads and abdomens of both species and posterior tibia of F. silvestrii (which carry plant resin), as well as to the pure compounds 2-heptanol and 2-nonanol, which occur in the mandibular glands of both species, and to the terpenes alpha-cubebene, humulene, and beta-caryophyllene found on their tibia and in the cerumen of their nests.
Age and growth of the porthole shovelnose catfish (Hemisorubim platyrhynchos) in the Pantanal
Authors: Penha J. M. F. , Mateus L. A. F. , Barbieri G.
Published: April 2005

The Porthole Shovelnose Catfish, Hemisorubim platyrhynchos, is the sixth largest pimelodidae of the Pantanal. Its age and growth were studied using pectoral fin-spines from fish collected in the Cuiabá river basin, Pantanal. The fish, which came from commercial and experimental fisheries, were all caught with hook and line. Growth-ring formation time could not be defined through the Kruskal-Wallis test on marginal increment (H = 4.142; p = 0.247). Nevertheless, decrease in the marginal increment index occurring as waters recede suggests this as the probable time when growth rings form. Estimation of the parameters of von Bertalanffy growth curve, adjusted through nonlinear regression to observed fork lengths, with L¥ fixed at 64 cm, were: k = 0.222 year-1; t o = -2.149 years. Individual life span was estimated at 11.4 years. The results suggest that fork length is a good predictor of age for individuals of this species.
Empirical diversity indices applied to forest communities in different successional stages
Authors: Petrere Jr M. , Giordano L. C. , De Marco Jr. P.
Published: April 2005

In this paper we examine the precision of six diversity indices, four of them empirical when including in their formulae climax adaptation numbers. These numbers define the succession position of the plant species in five forest areas in São Paulo State. We simulated hypothetical forests and compared the results with a list of species in the five areas. Low agreement was found among the indices in succession stages. Including the climax adaptation numbers increased precision for only some indices.
Flooded native pastures of the northern region of the Pantanal of Mato Grosso: biomass and primary productivity variations
Authors: Pozer C. G. , Nogueira F.
Published: April 2005

The Pantanal comprises a number of landscape units, submitted to a flood pulse with variable intensity or regularity. One of these units, the flooded plains, is important in cattle raising. This study was carried out in the northern portion of the Pantanal and presents data related to the productive dynamics of the flooded native pastures both protected from and exposed to cattle. The greatest total biomass values were for the protected pasture due to accumulated dead biomass. Net primary production presented smaller values at the flood-season start and increasing gradually beginning in the subsequent rainy season. However, consumption by cattle was also more intense during the months of greater precipitation. The effect of cattle in pastures is of fundamental importance to management since it prevents the dead biomass excess that increases fire risks.
Birds of a habitat spectrum in the Itirapina Savanna, São Paulo, Brazil (1982-2003)
Authors: Willis E. O.
Published: April 2005

Some 231 birds were recorded on a sandy plateau in central São Paulo, in an area forming a natural "habitat spectrum", from dry or wet grasslands to bushy ones (campo-cerrado) plus gallery scrub, marshes, and low woods. Subtracting 12 species that mostly flew over, and 56 species that seemed to be vagrants or accidental visitors, 163 species were regular (including 14 that center in nearby anthropogenically-modified zones). The 69 in gallery areas are mostly regionally common woodland species, but one southeastern species has disappeared over the years and three northwestern dry-forest species have entered. The 81 grassland species include several rare birds, and hence are important despite exhibiting lower biodiversity than in regional forest areas. Seven rare species disappeared over the years, some due to lack of fires, others because of either recent "greenhouse" dry years or protected vegetation growing to taller campo-cerrado. Several other species are becoming rare. Low vegetation forms a spectrum of temporally unstable habitats that change rapidly; one needs actively managed large areas and corridors even though many open-area birds can fly long distances to varying habitat patches.
Pollen treatment in high osmotic potential: a simple tool for in vitro preservation and manipulation of viability in gametophytic populations
Authors: Loguercio Leandro Lopes
Published: April 2005

A method for in vitro preservation and manipulation of pollen viability based on simple changes in osmotic potential (sucrose concentrations) in culture media was developed using tobacco pollen as the experimental model. High osmotic potentials were capable of reversibly inhibiting pollen germination, preserving its viability at room temperature for long periods, as assessed by subsequent incubation in germination medium. When pollen was pre-germinated for different periods and subsequently incubated in 80 % sucrose medium (inhibiting medium) there was a progressive decrease in its viability, which was a trend best described by a quadratic regression line. Nevertheless, very small variations in pollen-tube lengths and viable pollen grains more resistant to the pre-germination step were detected by this procedure. Consequences and potential applications of these findings were discussed for use in analyses of variability, selection in gametophytic populations and pollen storage.
The effect of chilling on the photosynthetic activity in coffee (Coffea arabica L.) seedlings: The protective action of chloroplastid pigments
Authors: Oliveira Jurandi Gonçalves de , Alves Pedro Luis C.A. , Magalhães Antonio Celso
Published: April 2005

Coffea arabica is considered to be sensitive to low temperatures, being affected throughout its entire life cycle. Injury caused by chilling (low temperatures above zero degree centigrade) is characterized primarily by inhibition of the photosynthetic process. The objective of this work was to evaluate the role of photosynthetic pigments in the tolerance of coffee (C. arabica L.) seedlings to chilling. The evaluation the photosynthetic activity was made by emission of Chl a fluorescence at room temperature (25 ºC) in vivo and in situ, using a portable fluorometer. The pigment content was obtained by extraction with 80 % acetone, while estimation of membrane lipid peroxidation was determined by measuring the MDA content in leaf tissue extracts. The results indicated a generalized reduction in the quantum yield of PSII when the seedlings were maintained in the dark. The reduction occurred in the seedlings submitted to chilling treatment as well as in the control ones. This demonstrates that not only chilling acts to cause an alteration in PSII. It is possible that the tissue storage reserves had been totally exhausted, with the respiratory rate exceeding the photosynthetic rate; the later was nil, since the seedlings were kept in the dark. The efficiency in the capture, transfer and utilization of light energy in PS II photochemical reactions requires a sequence of photochemical, biochemical and biophysical events which depend on the structural integrity of the photosynthetic apparatus. However, this efficiency was found to be related to the protective action of chloroplastid pigments, rather than to the concentration of these pigments.
Photochemical efficiency in bean plants (Phaseolus vulgaris L. and Vigna unguiculata L. Walp) during recovery from high temperature stress
Authors: Costa Ernany Santos , Bressan-Smith Ricardo , Oliveira Jurandi Gonçalves de , Campostrini Eliemar , Pimentel Carlos
Published: April 2005

Bean (Phaseolus vulgaris L., cv. Carioca and cv. Negro Huasteco) and cowpea plants (Vigna unguiculata L. Walp cv. Epace 10) were grown in a growth chamber with PPF at leaf level of 200 mumol.m-2.s-1 and air temperature 25 + 1 ºC. The first fully expanded pair of leaves of 12-day-old plants was submitted to high temperature stress (25, 30, 35, 40, 45 and 48 ºC) for 1.5 h. The photochemical efficiency of PSII during recovery was monitored by means of chlorophyll a fluorescence at six different times (0.5, 1, 2, 4, 24, and 48 h) after stress, at 25 ºC, using a modulated fluorimeter. Increasing temperature promoted an increase in Fphi at 45 ºC, possibly associated with dissociation of the light harvesting complex from the reaction centre of PSII, but a decrease was observed at 48 ºC in all cultivars. Fmax decreased at 48 ºC in Carioca and Negro Huasteco, but not in Epace 10, showing a possible correlation between heat tolerance and Fmax for this cultivar. The low values of Fmax in Carioca and Negro Huasteco indicated a loss of PSII activity followed by death of these plants. Fv/Fmax did not vary in Epace 10 but varied in Carioca and Negro Huasteco with increasing temperatures.
Sensibilidade estomática ao ABA em função do pH e de níveis de Ca2+, NO3- e PO4(3-) na seiva do xilema
Authors: Oliveira Maria Neudes Sousa de , Oliva Marco Antonio , Martínez Carlos Alberto , Mercier Helenice , Silva Marco Aurélio Pedron e
Published: April 2005

A hipótese de que a sensibilidade estomática ao ácido abscísico (ABA) possa ser influenciada pelas características da seiva xilemática, como pH e concentração de Ca2+, NO3- e PO4(3-), foi testada em plantas de Lycopersicon esculentum L. var. Santa Clara submetidas a estresse hídrico induzido pela adição de PEG 6000 à solução nutritiva. Estimou-se a sensibilidade estomática ao ABA pela relação transpiração/ABA xilemático. Plantas intactas foram submetidas a estresse hídrico rápido e lento e determinaram-se as variações de pH e as concentrações de Ca2+, NO3- e PO4(3-) na seiva do xilema Também se estudaram os efeitos de diversas concentrações de Ca2+, NO3- e PO4(3-) sobre a transpiração em folhas destacadas imersas em seiva artificial contendo ABA exógeno. Nas plantas intactas submetidas a estresse rápido, o aumento nas concentrações de Ca2+, NO3- e PO4(3-) levou a um gradativo acréscimo da sensibilidade estomática ao ABA contido no xilema. Com estresse lento, o Ca2+ não influenciou a sensibilidade estomática ao ABA. Em folhas destacadas, a concentração de ABA exógeno necessário para promover redução na taxa transpiratória foi de 2,5 miM. A presença de Ca2+ na seiva xilemática estimulou o efeito inibitório sobre a taxa transpiratória, promovido pelo ABA. O aumento nas concentrações de Ca2+ e NO3- na seiva artificial intensificou o fechamento estomático induzido por ABA.
Possible involvement of proteasome activity in ethylene-induced germination of dormant sunflower embryos
Authors: Borghetti Fabian , Noda Fabio Nakamura , Sá Cezar Martins de
Published: April 2005

Freshly harvested sunflower seeds (Helianthus annuus L., Asteraceae) present physiological dormancy localized at the embrionary axis which prevents germination at low temperatures. However, dormant embryos reach about 100 % germination when incubated with the phytohormone ethylene during imbibition. To examine whether proteinase activities are implicated in the breaking of dormancy by ethylene, dormant embryos were treated with the proteinase inhibitors leupeptin, E64 and the proteasome specific inhibitor clasto-lactacystin ß-lactone (lactacystin). A few embryos (< 10 %) germinated at 10 ºC in absence of ethylene but ethylene-treated embryos reached high germinability (~90 %) in the presence of leupeptin, E64, water and DMSO. On the other hand, incubation in lactacystin strongly reduced (< 20 %) the ethylene-induced germination in a dose-dependent manner. Lactacystin did not affect the germinability at 25 ºC (temperature in which the embryos are no longer dormant) but increased the average germination time. The results suggest that proteasome activity may be involved in the removal of dormancy by ethylene and in the progression of the germination of sunflower embryos.
Primary metabolism components of seeds from Brazilian Amazon tree species
Authors: Gonçalves José Francisco de C. , Fernandes Andreia V. , Oliveira Antonio Fernando M. , Rodrigues Lílian F. , Marenco Ricardo A.
Published: April 2005

The contents of the main components of the primary metabolism (soluble sugars, starch, proteins, oils, fatty acids) and minerals (P, Ca, Mg, K, Fe, Zn, Mn, Cu) were characterized in seeds of five Brazilian Amazon tree species (Andira parviflora, Bertholletia excelsa, Helicostylis tomentosa, Hymenaea parviflora, and Parkia pendula). Soluble sugar contents were high in P. pendula seeds (14 %), whereas starch predominated in A. parviflora seeds (58.7 %). A. parviflora and H. parviflora seeds were rich in proteins (35.1 % and 32.4 %, respectively). The oil contents ranged from 1.4 % in A. parviflora to 70.7 % in B. excelsa. Only B. excelsa and P. pendula seeds may be considered oilseeds, with 70.7 % and 28.4 % oil, respectively. The fatty acid compositions showed high proportions of unsaturated fatty acids, mainly oleic and linoleic acids, regardless of the species. B. excelsa and P. pendula also showed high amounts of P, Mg, K and Zn.
High temperature effects on the response of photosynthesis to light in sweet orange plants infected with Xylella fastidiosa
Authors: Ribeiro Rafael Vasconcelos , Machado Eduardo Caruso , Oliveira Ricardo Ferraz de , Pimentel Carlos
Published: April 2005

The objective of this study was to evaluate the high temperature effects on the response of photosynthesis to light in sweet orange plants infected with Xylella fastidiosa. This vascular bacterium is the causal agent of the citrus variegated chlorosis that causes severe economical losses to the Brazilian citrus industry. The responses of the photosynthetic oxygen evolution and the parameters related to chlorophyll a fluorescence to the increase in light intensity were evaluated at 35ºC and 45ºC in both healthy and infected leaf discs. The increase in temperature affected the photosynthetic apparatus of both healthy and infected plants, although infected plants showed higher photochemical sensitivity at the higher temperature (e.g. in the potential quantum efficiency of photosystem II, maximum and basal fluorescence yield, and in the relation between variable and basal fluorescence yield). This higher sensitivity of infected plants was not reflected in the overall photosynthetic reaction, since photosynthetic oxygen evolution values did not vary at 45ºC. Healthy and infected plants showed differences in photosynthetic oxygen evolution but displayed similar effective quantum efficiency of photosystem II as well as apparent electron transport rates at 35ºC. These results suggest that the limitations in photosynthesis observed on the infected plants might arise through impaired biochemical reactions.
Physiological responses of NaCl stressed cowpea plants grown in nutrient solution supplemented with CaCl2
Authors: Silva José Vieira , Lacerda Claudivan Feitosa de , Costa Paulo Henrique Alves da , Enéas Filho Joaquim , Gomes Filho Enéas , Prisco José Tarquínio
Published: April 2005

Pitiuba cowpea (Vigna unguiculata (L.) Walp.) plants were grown in nutrient solution and kept in a greenhouse up to pre-flowering stage. They were subjected to four different treatments: nutrient solution; nutrient solution containing 75 mmol.L-1 NaCl; nutrient solution containing 75 mmol.L-1 NaCl and 5 mmol.L-1 CaCl2; and nutrient solution containing 75 mmol.L-1 NaCl and 10 mmol.L-1 CaCl2. Salt stress strongly inhibited plant growth, caused a disturbance in plant-water balance, and increased the total content of inorganic solutes in the different plant parts, due mainly to accumulation of Na+ and Cl-. It also increased leaf and root soluble carbohydrates, reduced soluble amino nitrogen both in root tips and in the youngest trifoliate leaves, and reduced proline levels in root tips. Although the addition of CaCl2 to the root environment of salt stressed plants caused a reduction in Na+ content, specially in roots, it did not ameliorate the salt stress effects on plant-water relations and growth. Therefore, the results obtained do not support the hypothesis that supplemental calcium would ameliorate the inhibitory effects of NaCl-stress.
Purification and molecular mass determination of a lipid transfer protein exuded from Vigna unguiculata seeds
Authors: Diz Mariângela S. S. , Carvalho André O. , Gomes Valdirene M.
Published: April 2005

Plants exude a variety of substances through their surface especially of roots and germinating seeds. Some of these released compounds seem to have an inhibitory action against certain pathogens. Lipid transfer proteins (LTPs) are 9 kDa cysteine-rich cationic peptides and are thought to play a role in the protection of plants against microbial infections. The aim of this work was to isolate and determine the molecular mass of a LTP present in the exudates of imbibed cowpea seeds. For exudation induction, 50 seeds were submerged in 50 mL sterile 100 mmol.L-1 Na-acetate buffer, pH 4.5 and shaken at 30 ºC for 24 h. The resulting exudate was subjected to ammonium sulphate fractionation and the pellet formed between 0 and 70 % saturation was dialysed and recovered by freeze drying. Further purification steps were carried out using chromatographic methods and the molecular mass of the LTP determined. All of these steps were monitored by SDS-Tricine gel electrophoresis and Western blotting using an anti-LTP serum. The purified LTP showed a relative molecular mass of 9 kDa.
Exploring drought tolerance in coffee: a physiological approach with some insights for plant breeding
Authors: DaMatta Fábio Murilo
Published: April 2005

This paper briefly reviews some selected traits (leaf area, crown architecture, water-use efficiency and carbon isotope discrimination, water relations and root characteristics), which may be explored in breeding programmes to tolerance to drought stress in arabica and robusta coffee.
Comparative stomatal conductance and chlorophyll a fluorescence in leaves vs. fruits of the cerrado legume tree, Dalbergia miscolobium
Authors: Lemos Filho José Pires de , Isaias Rosy Mary dos Santos
Published: April 2005

The aim of this study was to compare water vapor conductance and chlorophyll a fluorescence between leaflets and fruits of Dalbergia miscolobium, the Jacaranda tree. The frequency of stomata on the leaflets was 20 times higher than that observed on the fruits, and this was related with the lower conductance of the fruits in comparison with the leaflets. The potential quantum yield of PSII (Fv /Fmax) was significantly lower in fruits than in leaflets. The Fv /Fmax values for leaflets increased to over 0.8 during the afternoon, indicating the occurrence of dynamic photoinhibition. In contrast, Fv /Fmax values for fruits remained low even at early morning, indicating the occurrence of chronic photoinhibition. The maximum values of effective quantum yield (deltaF/F'm), and of the apparent electron transport rate (ETRmax) were higher in leaflets than in fruits. It was concluded that, like other green tissues, the pericarp of D. miscolobium was photosynthetically active, and therefore can contribute to the maintenance of the fruits and/or to the development of the seeds.
EgLFY, the Eucalyptus grandis homolog of the Arabidopsis gene LEAFY is expressed in reproductive and vegetative tissues
Authors: Dornelas Marcelo Carnier , Amaral Weber A. Neves do , Rodriguez Adriana Pinheiro Martinelli
Published: April 2005

The EgLFY gene cloned from Eucalyptus grandis has sequence homology to the floral meristem identity gene LEAFY (LFY) from Arabidopsis and FLORICAULA (FLO) from Antirrhinum. EgLFY is preferentially expressed in the developing eucalypt floral organs in a pattern similar to that described previously for the Arabidopsis LFY. In situ hybridization experiments have shown that EgLFY is strongly expressed in the early floral meristem and then successively in the primordia of sepals, petals, stamens and carpels. It is also expressed in the leaf primordia of adult trees. The expression of the EgLFY coding region under control of the Arabidopsis LFY promoter could complement strong lfy mutations in transgenic Arabidopsis plants. These data suggest that EgLFY plays a similar role to LFY in flower development and that the basic mechanisms involved in flower initiation and development in Eucalyptus may be similar to those occurring in Arabidopsis.
Changes in growth and superoxide dismutase activity in Hydrilla verticillata L. under abiotic stress
Authors: Panda Sanjib Kumar , Khan Mohammad Hussain
Published: April 2005

A study was made of the role of various heavy metals (chromium, zinc, copper and cadmium) together with the effects of NaCl-salinity, PEG-mediated water stress and temperature on growth and superoxide dismutase (SOD) activity in hydrilla (Hydrilla verticillata L.). Almost all metals studied reduced growth but presented a modulatory effect at lower concentrations. NaCl-salinity, water stress and temperature treatments also reduced growth. SOD activity was inhibited by both chromium and zinc but increased by copper and cadmium. NaCl-salinity increased SOD activity while water stress decreased it. SOD showed thermostability with a higher activity being recorded at 45ºC.
Interactions between leaf water potential, stomatal conductance and abscisic acid content of orange trees submitted to drought stress
Authors: Gomes Mara de Menezes de Assis , Lagôa Ana Maria Magalhães Andrade , Medina Camilo Lázaro , Machado Eduardo Caruso , Machado Marcos Antônio
Published: April 2005

Thirty-month-old 'Pêra' orange trees grafted on 'Rangpur' lemon trees grown in 100 L pots were submitted to water stress by the suspension of irrigation. CO2 assimilation (A), transpiration (E) and stomatal conductance (g s) values declined from the seventh day of stress, although the leaf water potential at 6:00 a.m. (psipd) and at 2:00 p.m. (psi2) began to decline from the fifth day of water deficiency. The CO2 intercellular concentration (Ci) of water-stressed plants increased from the seventh day, reaching a maximum concentration on the day of most severe stress. The carboxylation efficiency, as revealed by the ratio A/Ci was low on this day and did not show the same values of non-stressed plants even after ten days of rewatering. After five days of rewatering only psi pd and psi2 were similar to control plants while A, E and g s were still different. When psi2 decreases, there was a trend for increasing abscisic acid (ABA) concentration in the leaves. Similarly, stomatal conductance was found to decrease as a function of decreasing psi2. ABA accumulation and stomatal closure occurred when psi2 was lower than -1.0 MPa. Water stress in 'Pera´ orange trees increased abscisic acid content with consequent stomatal closure and decreased psi2 values.
Pediatric HIV-related oral manifestations: a five-year retrospective study
Authors: Soares Lívia Ferreira , Castro Glória Fernanda Barbosa de Araújo , Souza Ivete Pomarico Ribeiro de , Pinheiro Melissa
Published: April 2005

The purpose of this study was to carry out a five-year retrospective descriptive follow-up of the oral manifestation frequency, systemic condition and type of medication used in HIV-infected children and adolescents after the introduction of combined antiretroviral therapy. Fifty-eight patients were examined in 2001/2002, and their previous medical and dental records (1997 to 2000) were researched from files. There was an occurrence of 7 new cases of AIDS in a sample of 19 children, while 46.5% of the entire sample (n = 58) progressed as to classification of HIV infection. No difference was noted among the frequencies of oral manifestations, categories of the immunosuppression and viral load categories. The oral manifestations in the group of children and adolescents followed up in this study remained stable, even after treatment with combined antiretroviral therapy. However, a downward trend in the frequency of oral candidiasis and parotid enlargement was noted.
Diffusion of calcitonin through the wall of the root canal
Authors: Camargo Selma Cristina Cury , Gavini Giulio , Aun Carlos Eduardo , Waterfield Douglas , Coil Jeffrey M.
Published: April 2005

The aim of this study was to evaluate the in vitro diffusion of synthetic salmon calcitonin (CT), used as an intracanal medication, to the external root surface, with or without the presence of intact root cementum. Fifty-four human central incisors were used in the experiment, and were divided into two groups of 21 (test groups) and two groups of 6 teeth (control groups). After root canal preparation, 10 ml of calcitonin was inserted within the root canal chamber. The root was sealed and made externally impermeable. Specimens were then placed in tubes with saline solution buffered with phosphates and stored at 37°C. The diffusion of calcitonin was measured after 1, 4 and 7 days. To count calcitonin present at the external media (PBS), ELISA test (an antigen-antibody reaction) was used. Results showed that there was calcitonin diffusion through dentin in all of the test samples. The absence of cementum increased the diffusion of calcitonin (p=0.05). The highest counts of CT were obtained on day 7 for groups with or without cementum - showing a direct relation between time and diffusion of the medication.
In vitro antifungal susceptibility of Candida spp. isolates from patients with chronic periodontitis and from control patients
Authors: Ito Cristiane Yumi Koga , Martins Clélia Aparecida de Paiva , Loberto Jussara Cia Sanches , Santos Silvana Soléo Ferreira dos , Jorge Antonio Olavo Cardoso
Published: April 2005

Superinfection by Candida can be refractory to conventional periodontal treatments in specific situations, such as in immunocompromised patients. In these cases, the systemic therapy with antifungal drugs could be indicated. The aim of this study was to analyse antifungal susceptibility of Candida spp. strains isolated from chronic periodontitis patients and from control individuals. A total of 39 C. albicans isolates, 9 C. tropicalis, 2 C. glabrata and 5 Candida spp. from control individuals and 30 C. albicans, 3 C. tropicalis and 2 C. glabrata from periodontitis patients were tested. In the control group, 1 isolate of C. glabrata was resistant to ketoconazole and 1 Candida spp. was resistant to amphotericin B, ketoconazole and miconazole. Among the isolates of periodontitis group, 1 (3.33%) C. albicans isolate was resistant to flucytosine and ketoconazole. According to the obtained results, it could be concluded that fluconazole was the most effective drug against the several Candida species studied. There were not expressive differences in the susceptibility of isolates from periodontitis patients or from control individuals.
Impact of oral health on quality of life among the elderly population of Joaçaba, Santa Catarina, Brazil
Authors: Biazevic Maria Gabriela Haye , Michel-Crosato Edgard , Iagher Fabíola , Pooter Cleiton Eduardo , Correa Silvia Letícia , Grasel Cláudia Elisa
Published: April 2005

The objective of this study was to investigate the impact of oral health conditions on the quality of life of elderly people in Joaçaba - SC, in Southern Brazil. A survey based on systematic sampling of clusters was carried out with 183 elderly people that belong to old age groups. The survey was conducted in order to assess the oral conditions of the participants (use of and need for prosthesis) based on the criteria from the World Health Organization publication "Oral Health Surveys, Basic Methods", 4th edition. The oral health impact profile (OHIP) was used to evaluate the impact of oral condition in the quality of life. ABIPEME (Brazilian Association of Market Research Institutes) criterion was used, together with the level of education and the number of people in the household to determine social inequalities. The participants were mostly women (82%) and the OHIP mean was 10.35. No correlation was observed between the OHIP level and formal education or between OHIP and number of residents per household. There was a correlation of 0.240 (p = 0.001) between ABIPEME and OHIP. The OHIP mean for those not using maxillary prosthesis was 12.48 and the mean for those using it was 9.81 (p = 0.399). The mean OHIP for those in need of maxillary prosthesis for those who did not need it was 13.00 and 8.88, respectively (p = 0.014). The same trend was found for the use and need for mandibular prosthesis. The conclusion was that the need for maxillary and mandibular prosthesis impacted the quality of life among the elderly population of Joaçaba.
Current data on the characterization of oral clefts in Brazil
Authors: Freitas José Alberto de Souza , Dalben Gisele da Silva , Santamaria Júnior Milton , Freitas Patrícia Zambonato
Published: April 2005

This study aimed at investigating the current distribution of the several types of clefts among the patients receiving treatment at the Hospital for Rehabilitation of Craniofacial Anomalies (HRAC-USP), Bauru, Brazil, for the first time during the year 2000. A total of 803 unoperated patients with cleft lip and/or palate, with or without additional malformations, with no recognizable syndromes, who came to the HRAC-USP for enrollment for treatment during the year 2000. A predominance of complete cleft lip and palate, either unilateral or bilateral, was observed (37.1%), followed by isolated cleft palate (31.7%) and isolated cleft lip (28.4%). A discrete relationship between cleft palate and the female gender was noticed (53%), and males were more affected by the other types of clefts (around 60%). The findings revealed a predominance of complete clefts of the primary and secondary palate, the treatment of which is more complex, and whose frequency is greater in males.
Effect of alteration in organic material of the occlusal caries on DIAGNOdent readings
Authors: Mendes Fausto Medeiros , Pinheiro Sérgio Luiz , Bengtson Antonio Lucindo
Published: April 2005

DIAGNOdent is a laser fluorescence device used for dental caries diagnosis in occlusal and smooth surfaces. Despite the promising preliminary results, the molecules involved in the increase of fluorescence in carious lesions remain unclear. The aim of this study was to compare the laser fluorescence readings before and after changes in the organic material of occlusal carious lesions in primary teeth. Twenty-four primary molars stored in saline solution with at least one site with occlusal caries were divided into two groups. The control group had 17 sites with caries and the experimental one had 16 sites. The carious lesions were measured with laser fluorescence. The experimental samples were then removed from the storage solution and immersed in a 2% sodium hypochlorite solution for 24 hours. After washing with water, the teeth were measured again with the laser fluorescence device. The teeth of the control group were submitted to the same procedures, but saline solution was used instead of the sodium hypochlorite solution. A statistically significant reduction in the mean of the readings after immersion in the two tested solutions compared with the initial readings was observed in both groups, but the decrease was statistically higher in the experimental group (p < 0.0001). In this study, the data indicate that changes in the fluorescence of carious lesions measured by the laser fluorescence are mainly due to the organic content alterations rather than to the mineral loss.
Correlation between visual and radiographic examinations of non-cavitated occlusal caries lesions: an in vivo study
Authors: Wolwacz Victor Ferrás , Chapper Ana , Busato Adair Luiz Stefanello , Barbosa Alcebíades Nunes
Published: April 2005

The aim of this study was to conduct an in vivo investigation of the correlation between the visual and radiographic scoring systems by Ekstrand et al.7 (1997) for the diagnosis of occlusal caries lesions. The study sample comprised 147 occlusal sites from 23 patients. Two trained and experienced examiners performed the clinical visual examinations. A third examiner, which was also trained, experienced and blind to the results of the visual clinical examination, performed the analysis of the bitewing radiographs. The correlation between visual and radiographic scores was assessed by Goodman & Kruskal's gamma correlation coefficient. Results showed a strong correlation between the scores for occlusal caries found in the visual and radiographic diagnosis systems used in this study.