bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative effect of glucagon and isoproterenol on hepatic glycogenolysis and glycolysis in isolated perfused liver
Authors: Vardanega-Peicher Márcia , Galletto Ricardo , Pagliarini e Silva Sarah , Bazotte Roberto Barbosa
Published: December 2006

The effect of glucagon and isoproterenol (beta-adrenergic agonist) on hepatic glycogenolysis and glycolysis in isolated perfused liver was compared. The levels of isoproterenol and glucagon which promoted the maximal activation of glycogenolysis were 20 muM and 1nM respectively. However, glucagon (1 nM) not only increased glycogenolysis but also inhibited glycolysis. Because adenosine-3'-5'-cyclic monophosphate (cAMP) is a common second messenger to glucagon and isoproterenol, the level of cAMP that simulates the effect of these substances were investigated. The concentration of cAMP that inhibited glycolysis was five times higher (15 muM) than that which stimulated glycogenolysis (3 muM). Similar inhibition of glycolysis was obtained with cAMP agonists resistant to phosphodiesterases, i.e., 8-Br-cAMP and N6-monobutyryl-cAMP (6-MB-cAMP) at the concentration of 3 muM. Thus, apparently glucagon could produce higher cellular levels of cAMP than that obtained with the activation of beta-adrenergic receptors. The higher amount of cAMP could be enough to overcome the action of phosphodiesterases and penetrate in the cytosol creating a favourable gradient to inhibit the enzymes of glycolysis.
Profile of the alcohols produced in fermentations with malt contaminated with trichothecenes
Authors: Reinehr Christian Oliveira , Furlong Eliana Badiale
Published: December 2006

In order to study the influence of mycotoxins on the production of alcohols, a fermentative process on a laboratorial scale was simulated. Malt was contaminated with deoxynivalenol and T-2 in different ratios (up to 500 ppb), according to a 3² factorial design, and the alcohols obtained after the fermentation were determined through gas chromatography. The results showed that trichothecenes influenced the profile of the alcohols produced by Saccharomyces cerevisiae during the fermentative process of malt, especially the profile of methyl and isoamyl alcohols.
Longissimus dorsi fatty acids composition of Bos indicus and Bos indicus x Bos taurus crossbred steers finished in pasture
Authors: Prado Ivanor Nunes do , Moreira Fernanda Barros , Matsushita Makoto , Souza Nilson Evelázio de
Published: December 2006

Studies were carried out to evaluate the fatty acids composition of Longissimus dorsi muscle, with or without fat thickness, of Bos indicus and Bos indicus x Bos taurus crossbred steers finished in millet (Pennisetum americanum L.) or star grass (Cynodon plectostachyus Pilger) pasture systems with mineral or mineral protein supplementation. Neither the treatment nor the genetic group had effect on meat fatty acids composition. The cut had effect on meat fatty acid composition. The meat without fat thickness had 11% of PUFA, 43% of MUFA and 45% of SFA. The meat with fat thickness had 5% of PUFA, 44% of MUFA and 50% of SFA. PUFA/SFA ratio was 0.10 and 0.25 and n-6/n-3 ratio was 0.80 and 1.27 for cuts with and without fat thickness.
The influence of light intensity on anatomical structure and pigment contents of Tradescantia pallida (Rose) Hunt. cv. purpurea Boom (Commelinaceae) leaves
Authors: Paiva Élder Antonio Sousa , Isaias Rosy Mary dos Santos , Vale Fernando Henrique Aguiar , Queiroz Cristina Generosa de Senna
Published: December 2006

The aim of this work was to study the effects of five different light intensities on the anatomical structure and on the pigment contents in leaves of Tradescantia pallida cv. purpurea. Once light intensity became lower, the thickness of leaf lamina and mesophyll were reduced. Adjustments in light-harvesting antenna size were observed: an increase in chlorophyll a + b/carotenoids ratio at low-light growth conditions. There was a strong positive linear correlation between the light intensity values and anthocyanin contents. Hence, T. pallida cv. purpurea acclimation to distinct environmental conditions might be related to its capacity of altering structurally and physiologically its phenotype.
Potencial for natural forest regeneration from seed bank in an upper Paraná river floodplain, Brazil
Authors: Campos João Batista , Souza Maria Conceição de
Published: December 2006

The historical process of deforestation was analyzed to evaluate the regeneration potential of forests from soil seed bank of Porto Rico island (53° 15'W and 22° 45'S) in the upper Paraná river floodplain. Remnant forest fragments were identified and measured and the structure of arboreous vegetation and the composition of the seed bank of the forests and grassland of the island were evaluated. Results showed a fast process of deforestation with critical levels of forest: the remaining twice fragments represented only 5.98% of the total surface of the island. Disturbance by cattle raised on the island continuously degraded the fragments (backward succession), while expansion of areas with pasture favored severe impoverishment of the seed banks flora. The latter factor, soil compaction, and characteristics of seeds of existing arboreous species in the bank suggested that the immediate reestablishment of vegetation was more conditioned to introduction processes of seeds (by rain and ''flood seed'') than by stock of seeds in the bank.
Limnological characteristics and seasonal changes in density and diversity of the phytoplanktonic community at the Caçó pond, Maranhão State, Brazil
Authors: Dellamano-Oliveira Maria José , Senna Pedro Américo Cabral , Taniguchi Glória Massae
Published: December 2006

Seasonal changes of the phytoplanktonic community and limnological abiotic characteristics of Caçó pond (Maranhão State, Brazil) was evaluated from two field researches during the rainy (April 1999) and dry (November 1999) seasons. Measurements of twelve chemical and physical variables and phytoplankton collections were carried out at eight sampling stations. The Chlorophyceae and Cyanobacteria groups were in highest fractions during the rainy and dry seasons, respectively. The limnological abiotic variables showed a homogenous spatial distribution. The cluster analysis, using Bray-Curtis distance, distinguished two major groups, represented by the most common and abundant species in both the periods. The results showed that the climate regime, due to the seasonal changes in pluviosity, was a determinant over the phytoplanktonic community structure at Caçó pond.
Temporal variation in Sargassum Biomass, Hypnea epiphytism and associated fauna
Authors: Leite Fosca Pedini Pereira , Turra Alexander
Published: December 2006

Studies were carried out to investigate the temporal variation in Sargassum biomass, Hypnea epiphytism and associated fauna. There was a marked variation in the biomass of Sargassum and Hypnea among various sampling periods. Low values for Sargassum were recorded in August and November, while the lower value for Hypnea biomass was recorded in August. An inverse relationship was found between Sargassum biomass and the intensity of Hypnea epiphytism. The density of the total fauna associated to Sargassum showed a marked reduction in May. This variation was influenced by the variation patterns of the dominant faunistic groups (Gastropoda, Gammaridea, Isopoda and Caridea). Significant positive relationships were found between the biomass of Sargassum and Sargassum+Hypnea with the total density of all faunistic groups (per macroalgae biomass unit). However, the influence of Hypnea epiphytism on the phytal organisms was not evidenced.
Plants and pollinating bees in Maringá, State of Paraná, Brazil
Authors: Toledo Vagner de Alencar Arnaut de , Fritzen Adriano Ernesto de Toledo , Neves Carolina Antunes , Ruvolo-Takasusuki Maria Claudia Colla , Sofia Silvia Helena , Terada Yoko
Published: December 2006

The present study was carried out to survey the bees as visitors to melliferous flora in the region of Maringá, state of Paraná, Brazil. A total of 331 insects were captured, and the fauna comprised 39.88% Trigona spinipes, 38.37% Apis mellifera, 8.16% Tetragonisca angustula, 3.93% Halictidae, 1.21% Megachilidae, 2.42% Anthophoridae, and 3.32% other Hymenoptera. Eleven plant species from nine families were observed. The four families most frequently visited by A. mellifera were Pontederiaceae (93.53%), Sterculiaceae and Polygoniaceae (47.22%), Apocynaceae and Apiaceae (42.86%). The families most visited by T. spinipes were Lamiaceae (64.70%), Apocynaceae (57.14%), Sterculiaceae (51.85%) and Anacardiaceae (48.39%), and the families most visited by T. angustula were (28.57%), Asteraceae (22.22%) and Labiatae (16.47%). Three species predominated in number of bee visits Dombeya wallichii (32.63%), Ocimum americanum (15.5%) and Antigonon leptopus (15.2%). T. angustula was the most frequent visitor of O. gratissimum flowers (60.87%).
Using egg albumin foam to extinguish fires
Authors: Alsaati Hytham A. , Ditzler Danielle , Burapatana Vorakan , Tanner Robert D.
Published: December 2006

Oil, coal and chemical fires are often difficult to put out using water. In certain hydrocarbon fires, protein foam can extinguish fires better than water by keeping air (oxygen) away from the flames and by ''blowing'' the flame away from its fuel source. Egg albumin is a relatively inexpensive protein and is representative of foaming proteins, which are candidates for use as fire suppression agents. This paper begins to deal with the effect of the foam bulk pH, foam protein concentration and generating air flow rate into the foam on the fire extinguishing time in laboratory experiments. A Bunsen burner was used to generate a small, controlled laboratory fire within a plastic container, which represented a point source in a partially open room in the experiments. The Bunsen burner represents a gaseous hydrocarbon fire, which can be difficult to extinguish. Both a low pH foam and one made with a high air flow rate favor a reduction in time required to put out the Bunsen burner flame.
Ethanol fermentation of a diluted molasses medium by Saccharomyces cerevisiae immobilized on chrysotile
Authors: Monte Alegre Ranulfo , Rigo Maurício , Joekes Inés
Published: December 2006

In this work, the catalytic role of chrysotile support on the acceleration of alcoholic fermentation under non-aseptic conditions by Saccharomyces cerevisiae was investigated. The fermentation medium employed consisted only of diluted sugar-cane molasses. In the batch fermentations process with immobilized yeasts, the initial rate of CO2 production increased roughly 27 % during the first 30 minutes, compared to systems containing no chrysotile. A study of continuous alcoholic fermentation with chrysotile in the reactor bed showed a higher ethanol production rate at the different dilution rates investigated compared to similar fermentations without chrysotile.
Differential expression of Zymomonas mobilis sucrase genes (sacB and sacC) in Escherichia coli and sucrase mutants of Zymomonas mobilis
Authors: Gurunathan Sangiliyandi , Gunasekaran Paramasamy
Published: December 2006

The sacB and sacC genes encoding levansucrase and extracellular sucrase respectively were independently subcloned in pBluescript (high copy number) and in Z. mobilis-E. coli shuttle vector, pZA22 (low copy number). The expression of these genes were compared under identical background of E. coli and Z. mobilis host. The level of sacB gene expression in E. coli was almost ten fold less than the expression of sacC gene, irrespective of the growth medium or the host strain. In Z. mobilis the expression of sacB and sacC genes was shown to be subject to carbon source dependent regulation. The transcript of sacB and sacC was three fold higher in cells grown on sucrose than in cells grown on glucose/fructose. Northern blot analysis revealed that the transcript levels of sacC was approximately 2-3 times higher than that of sacB. These results suggested that the expression of sacC gene was more pronounced than sacB.
Induction of leafy galls in Acacia mearnsii De Wild seedlings infected by Rhodococcus fascians
Authors: Quoirin Marguerite , Bona Cleusa , Souza Elizandra F. de , Schwartsburd Pedro B.
Published: December 2006

Plantlets of blackwattle (Acacia mearnsii De Wild) were inoculated with the bacterium Rhodococcus fascians and cultured in vitro. Leafy galls appeared at the cotyledonary nodes in 75% of the infected plants. The galls were separated from the plants and cultured on a medium containing three-quarters-strength MS salts (Murashige and Skoog, 1962), MS vitamins, 2% sucrose and an antibiotic (cephalothin), supplemented with or without 0.2% activated charcoal. Histological studies conducted from the sixth to the twenty-second day after plant infection revealed the presence of newly formed meristematic centers, first in the axillary region, then on the petioles and lamina of the leaflets around the apical meristem. Approximately 37% of the galls developed one shoot with both concentrations of cephalothin.
Esterase polymorphism marking cultivars of Manihot esculenta, Crantz
Authors: Resende Adriana Gazoli , Vidigal Filho Pedro Soares , Machado Maria de Fátima P. S.
Published: December 2006

Esterase isozymes were used to detected substrate-preference polymorphism in twenty cultivars of Manihot esculenta, and to show cultivar-specific variation of this species. A relatively complex extraction solution of proteins from leaves was needed to show a larger number of esterase isozymes. Similarity between cultivars from six groups ranged from 51 to 96%. The cultivars identified by the same name seemed to be biochemically different regarding esterase isozymes. Esterase isozyme electrophoretic patterns could, therefore, be used to discriminate the cultivars identified by the same name, and to monitor the vegetative propagation of cultivars maintained in the germplasm collection. In breeding strategies, isoesterase analysis could be used to avoid intercrossing between the similar genotypes.
Proline content and protein patterns in Eucalyptus grandis shoots submitted to high and low temperature shocks
Authors: Souza Gustavo M. , Cardoso Victor J. M. , Gonçalves Antonio N.
Published: December 2006

Proline content and protein patterns changes in response to temperature shocks of both acclimated and non acclimated E. grandis shoots cultivated in vitro were investigated. Analysis of soluble proteins through SDS-PAGE and proline were carried out after 12h at 12ºC (cold acclimation) or 33ºC (heat acclimation), and immediately after temperature shocks at 41ºC and 0ºC. Analyses were also performed 24h after the temperature shocks (recovery period). Temperature treatment at 0ºC did not change soluble protein patterns both in acclimatized and non acclimatized plants, whereas cold temperature induced high proline levels, which kept relatively high after recovery period. Three novel, probably HSPs, proteins (90.5, 75 and 39 kDa) were observed in both acclimated and non acclimated plants submitted to high temperatures. Plants exposed at 41ºC were able to recover from heat shocks after 24h, whereas they did not recover completely from cold shocks. The effect of the acclimation period on the recovering (homeostasis) varied depending on the parameter evaluated, and type and duration of the temperature shock.
ATP - bioluminescence as a technique to evaluate the microbiological quality of water in food industry
Authors: Costa Patrícia Dolabela , Andrade Nélio José de , Passos Frederico José Vieira , Brandão Sebastião César Cardoso , Rodrigues Carolina Gonçalves Freire
Published: December 2006

ATP-bioluminescence was used to evaluate the microbiological quality of water samples collected from the water supply, the water treatment system and from a dairy plant, including ammonia-cooling water and industrial water. For industrial water, there was relation between the ATP-bioluminescence technique and microbial count. There were no differences (p>0.05) between water supply and ammonia-cooling water samples for total and free ATP concentrations nor for the microbial counts. Different microbial ATP concentrations were found for these water samples. The results suggested that the physical chemical quality of ammonia cooling water decreased the RLU measurements slightly. It could be concluded that the total ATP concentration was the most effective technique to evaluate the microbiological quality of water used in the food indsutry by ATP-bioluminescence.
Fat body morphology of Eriopis connexa (coleoptera, coccinelidae) in function of two alimentary sources
Authors: Sarmento Renato de Almeida , Oliveira Hamilton Gomes de , Holtz Anderson Mathias , Silva Solange Marques da , Serrão José Eduardo , Pallini Ângelo
Published: December 2006

This work investigated the influence of two alimentary sources: aphids and mites, in the morphology of the fat body of E. connexa. Results showed that fat body cells of individuals fed with aphids presented areas more than three folds higher (511 ± 98,7µm²) than those of beetles fed with mites (162 ± 34,9µm²). Histochemical tests showed that nutrient amount stored in fat body was higher in lady-beetles fed on aphids.
Effect of host availability and egg load in Trichogramma platneri Nagarkatti (Hymenoptera: Trichogrammatidae) and its consequences on progeny quality
Authors: Hohmann Celso L. , Luck Robert F.
Published: December 2006

Experiments were conducted to determine whether Trichogramma platneri Nagarkatti manifested a somatic-gametic trade-off and whether it was affected by host availability and host size. Large wasps produced on Trichoplusia ni Hübner and limited to five or 15 T. ni eggs daily, produced a similar number of progeny as wasps offered hosts from emergence. Similar results were obtained when they were deprived of T. ni eggs for one, three, five, or ten days and then provided with unlimited hosts daily until death. In contrast, small wasps produced from Sitotroga cerealella (Olivier) and deprived of T. ni eggs for one to three days suffered a significant reduction in progeny production. Regardless of size, the egg load of non-ovipositing wasps increased significantly with time and a positive relationship existed between the life span of a female and the length of time she was deprived of hosts.
Temporal dynamics of stomatal conductance of plants under water deficit: can homeostasis be improved by more complex dynamics?
Authors: Souza Gustavo Maia , Oliveira Ricardo Ferraz de , Cardoso Victor José Mendes
Published: December 2006

In this study we hypothesized that chaotic or complex behavior of stomatal conductance could improve plant homeostasis after water deficit. Stomatal conductance of sunflower and sugar beet leaves was measured in plants grown either daily irrigation or under water deficit using an infrared gas analyzer. All measurements were performed under controlled environmental conditions. In order to measure a consistent time series, data were scored with time intervals of 20s during 6h. Lyapunov exponents, fractal dimensions, KS entropy and relative LZ complexity were calculated. Stomatal conductance in both irrigated and non-irrigated plants was chaotic-like. Plants under water deficit showed a trend to a more complex behaviour, mainly in sunflower that showed better homeostasis than in sugar beet. Some biological implications are discussed.
Effect of ivermectin on the life cycle and larval fat body of Culex quinquefasciatus
Authors: Alves Stenio Nunes , Serrão José Eduardo , Mocelin Giovani , Melo Alan Lane de
Published: December 2006

The present work investigated the behavior, survival rate and lethal effect of 1.5 ppb ivermectin on Culex quinquefasciatus larvae, based on morphological and biological parameters, and possible alterations of their fat body. Changes in the number of eggs/egg mass and length of the larval stage were investigated. For this experiment, 600 larvae of 3rd and 4th instars of the mosquito were tested. The laid eggs were separated and the hatched larvae were counted. Some larvae submitted to 1.5 ppb ivermectin solution were used to prepare samples for histological study. Results obtained showed that ivermectin in a concentration of 1.5 ppb caused paralysis to the larvae with a mortality rate of 73.38%, mobilization of substances stored in the fat body and reduction of the number of egg laid in the adult stage.
Urban secondary sewage: an alternative medium for the culture of Tetraselmis chuii (Prasinophyceae) and Dunaliella viridis (Chlorophyceae)
Authors: Costa Rauquírio André Albuquerque Marinho da , Koening Maria Luise , Macedo Sílvio José de
Published: December 2006

The effect of different concentrations (10, 20, 30 and 40%) of urban secondary sewage on the growth of Tetraselmis chuii (Prasinophyceae) and Dunaliella viridis (Chlorophyceae) was examined to verify the possibility of its use as an alternative culture medium for these species. Stocks and 700mL duplicate batch cultures were maintained under controlled laboratory conditions. 30% and 40% additions were the most efficient for the growth of both species. Statistical analysis of the adjusted growth (cell.mL-1) and biomass (µg chlorophyll-a.mL-1) curves performed using the Chi-square test (p<0.05) demonstrated significant differences between the nutritive medium f/2 and the 40% addition used for these two species. The results suggested that some of the concentrations tested here yielded satisfactory cell densities and growth rates when compared with other culture media (macroalgae, bovine and chicken manure extracts). Thus it could be used by semi intensive aquaculture systems.
Movement of southern elephant seals (Mirounga leonina L.) from Elephant Is. South Shetlands, Antarctica
Authors: Muelbert Mônica M. C. , Robaldo Ricardo B. , Martínes Pablo E. , Colares Elton P. , Bianchini Adalto , Setzer Alberto
Published: December 2006

In 1999, at-sea activity of two young southern elephant seal males (Mirounga leonina) from Elephant Is. (61º13'S, 55º23'W), Antarctica, was monitored and tracked for 9 months. The individuals were randomly selected, captured, sedated (Zoletil 50®- 1mg/kg), weighed, measured, bled, paint-marked and fitted with satellite tags (STDR - ST-6PPT, Telonics®, USA). Deployment of the STDR took about 45 min since each animal had a lower incisor tooth extracted for age determination. The seals exhibited individual behaviors. Seal "V"-23842 (BM ~ 801kg) moved from Elephant Is. (61.2ºS 55.3ºW) in Jan. 1999 to King George Is. (62.2ºS 58.1ºW) in Feb. 1999 when the tag stopped signaling. Seal "T"-23843 (BM ~ 656 kg) was restricted to the area around Elephant Is. (61.2ºS 54.4ºW - 61.6ºS 55.4ºW) from January to May 1999, when it started to move south-eastwards. Although the age of these individuals was not yet determined it was likely to explain the difference in the two patterns of movement reported here. The temporal and spatial association of these movements with areas of high productivity is being investigated to assess whether the observed distribution reflects foraging activity.
Evaluation of Apis mellifera Carniolan and Africanized honey bees in royal jelly production
Authors: Mouro Gisele Fernanda , Toledo Vagner de Alencar Arnaut de
Published: December 2006

Investigations were carried out to evaluate Africanized and Carniolan hybrid Apis mellifera honeybees in royal jelly production. Ten colonies were randomly collected in nature and housed in Langstroth beehives. Each hive was having two nuclei with five frames. In superior nucleus frame was containing 28 acrylic cups in two bars. The five colonies with the best production remained in the experiment and their queens replaced by the respective daughters. Carniolan queens were placed in the five Africanized honeybees colonies with lower production. The hybrid Carniolan showed a higher production (P=0.0001) of royal jelly per colony, in three-day collect (3.95 ± 2.92 g) when compared to the Africanized honeybees (2.23 ± 2.13 g). The Carniolan also had a higher percentage of larvae acceptance (55.45 ± 36.7%) compared to the Africanized honeybees (35.8 ± 28.3%).
Biodegradable films made from raw and acetylated cassava starch
Authors: Larotonda Fábio D. S. , Matsui Kátia N. , Soldi Valdir , Laurindo João B.
Published: December 2006

Studies were carried out to produce biodegradable films from cassava starch. Two alternatives were investigated. In the first, films were obtained by starch gelatinization followed by thermopressing and glycerol was used at different concentrations as a plasticizer. In the second, starch acetate films were obtained by solubilization of cassava starch acetate in organic solvents, followed by casting on a glass plate and drying at room temperature. The films obtained by gelatinization were transparent and resistant to traction. The starch acetate films were also transparent but breakable. The use of these starch acetate films in paper impregnation improved the mechanical properties of the paper.
Mesozooplankton of an impacted bay in North Eastern Brazil
Authors: Silva Andréa Pinto , Neumann-Leitão Sigrid , Schwamborn Ralf , Gusmão Lúcia Maria de Oliveira , Silva Tâmara de Almeida e
Published: December 2006

Mesozooplankton abundance and distribution at Suape Bay, Pernambuco, was studied to assess the impacts caused by the construction of an internal port to increase the capacity of the Suape Port Complex. Zooplankton sampling was done at 3 stations during the dry (November-December/1997) and rainy (April-May/1998) seasons. A plankton net with 300 µm mesh size was used. Wet weight plankton biomass ranged from 44 mg.m-3 to 3,638 mg.m-3. Forty-five macrozooplankton taxa were registered. The most abundant was Copepoda. Among copepods, Acartia lilljeborgi, Parvocalanus crassirostris, Oithona hebes, Corycaeus (C.) speciosus and Temora turbinata were most frequent. Minimum abundance was 9 ind.m-3 and maximum was 2,532 ind.m-3. Average species diversity was 2.55 bits.ind-1. As a whole, Suape Bay has been under severe environmental stress and it seemed reasonable to assume that the recent modifications of the basin have resulted in changes in species composition and trophic structure, with an increase in marine influence.
Effect of polymers associated with N and K fertilizer sources on Dendrathema grandiflorum growth and K, Ca and Mg relations
Authors: Regiane Cristina Marcato Sita , Reissmann Carlos Bruno , Marques Renato , Oliveira Edilson de , Taffarel Angela Daniela
Published: December 2006

This study was conducted to evaluate the effect of polymer used with different nitrogen and potassium sources on the growth and nutrition of chrysanthemum (Dendranthema grandiforum, var. "Virginal") and on chemical characteristics of substrate. Two substrates were evaluated: 1) composite with 50 % organic soil, 45 % sand, and 5 % composted tobacco; 2) plow layer soil (0-20 cm depth; red oxisol typical dystrophic). The experimental design was a factorial (4x2x2) and included four polymer rates (0, 1, 2, and 4 g kg-1of substrate), two nitrogen ((NH4)2SO4 and (H2N)2CO), and two potassium (KCl and K2SO4) sources. Dry biomass, flower number, and concentration of K, Ca, and Mg were evaluated. Inverse relationships between polymer rates and plant biomass, macronutrient uptake were noticed, regardless substrate or nutrient source.
Floral biology and behavior of Africanized honeybees Apis mellifera in soybean (Glycine max L. Merril)
Authors: Chiari Wainer César , Toledo Vagner de Alencar Arnaut de , Ruvolo-Takasusuki Maria Claudia Colla , Attencia Valeria Maria , Costa Fabiana Martins , Kotaka Carolina Satie , Sakaguti Eduardo Shiguero , Magalhães Helida Regina
Published: December 2006

This research was carried out to evaluate the pollination by Africanized honeybees Apis mellifera, the floral biology and to observe the hoarding behavior in the soybean flowers (Glycine max Merril), var. BRS-133. The treatments were constituted of demarcated areas for free visitation of insects, covered areas by cages with a honeybee colony (A. mellifera) and also covered areas by cage without insects visitation. All areas had 24 m² (4m x 6m). The soybean flowers stayed open for a larger time (82.82 ± 3.48 hours) in covered area without honeybees. The stigma of the flowers was also more receptive (P=0.0021) in covered area without honeybees (87.3 ± 33.0%) and at 10:42 o'clock was the schedule of greater receptivity. The pollen stayed viable in all treatments, the average was 99.60 ± 0.02%, which did not present differences among treatments. The percentage of abortion of the flowers was 82.91% in covered area without honeybees, this result was superior (P=0.0002) to the 52.66% and 53.95% of the treatments uncovered and covered with honeybees, respectively. Honeybees were responsible for 87.7% of the pollination accomplished by the insects. The medium amounts of total sugar and glucose measured in the nectar of the flowers were, 14.33 ± 0.96 mg/flower and 3.61 ± 0.36 mg/ flower, respectively, not showing differences (P<0.05) among the treatments. The total solids, measured through the manual refratometer were 21.33 ± 0.22% in uncovered area and 22.33 ± 0.38% in covered with honeybees and differed to each other (P=0.0001). The honeybees were the most frequent insect (95.18%). Other observed insects were the Lepidoptera with 3.51% and other bees with 1.32%, in uncovered area. Honeybees visited 2.24 flowers on average in uncovered area and 1.58 in covered with honeybees and presented behavior for nectar hoarding and hoarding nectar/pollen in this period. In uncovered area the time of nectar hoarding was 2.55 ± 0.07 seconds, this time was smaller (P=0.0039) than 2.87 ± 0.08 seconds observed in covered area with honeybees. The behavior for the hoarding type observed in honeybees foraging the soybean flowers, through the content of its honey stomach and pollen loads of its pollen basket showed that the nectar forager did not show a pattern for the nectar collection, but for the pollen collection the schedule of pollen peak of the forager was at 11:36 o'clock. The soybean flowers showed alteration in floral biology when exposed to honeybees.
Spectrophotometric determination of total proteins in blood plasma: a comparative study among dye-binding methods
Authors: Zaia Dimas Augusto Morozin , Marques Fábio Rangel , Zaia Cássia Thaïs Bussamra Vieira
Published: December 2006

A comparative study between the biuret method (standard method for total proteins) and spectrophotometric methods using dyes (Bradford, 3',3",5',5"-tetrabromophenolphthalein ethyl ester-TBPEE, and erythrosin-B) was carried out for the determination of total proteins in blood plasma from rats. Bradford method showed the highest sensitivity for proteins and biuret method showed the lowest. For all the methods, the absorbance for different proteins (BSA, casein, and egg albumin) was measured and Bradford method showed the lowest variation of absorbance. The concentration of total protein obtained by using Bradford method was not statistically different (p>0.05) from concentration of total protein obtained by the biuret method. But in regard to erythrosin-B and TBPEE methods the concentrations of total protein were statistically different (p<0.05). Thus, Bradford method could be used instead of the biuret method for determination of total proteins in blood plasma.
Microbiological analysis of critical points in the chicken industry
Authors: Cansian Rogério Luis , Floriani Salete Teresa Radeski , Valduga Eunice
Published: December 2006

This work is focused on identifying microbial contamination in the scalding asepsis and cooling processes as well as in fresh sausages obtained. Salmonella was identified in two scald water samples but was absent in the water from chiller and in the final product, which might be explained in terms of chlorine addition and temperature reduction. The analysis revealed that MPN of Escherichia coli was in the range of <1-11/mL in the scald water and <1-64/mL in the chiller. Aeromonas sp. count showed 5 to 3.5x10¹ CFU/mL in the scald water and 9 to 3.7x10² CFU/mL in the chiller, probably due to the psycrophile characteristics of Aeromonas and evisceration process. The analysis of fresh sausages chicken revealed a sharp increase in the Aeromonas count (2.5x10³ CFU/g). Results showed the need of including Aeromonas analyzes in microbiological tests of foods.
An evaluation of antibacterial activities of Psidium guajava (L.)
Authors: Sanches Neviton Rogério , Garcia Cortez Diógenes Aparício , Schiavini Michelle Simone , Nakamura Celso Vataru , Dias Filho Benedito Prado
Published: December 2006

The present study was designated to evaluate the antibacterial activities of aqueous and ethanol:water extracts from leaves, roots and stem bark of Psidium guajava L. The antibacterial activities of the extracts against bacteria were tested by using both microdilution assay. The aqueous extracts of P. guajava leaves, roots and stem bark were active against the gram-positive bacteria Staphylococcus aureus (MICs=500, 125 and 250 µg/ml, respectively) and Bacillus subtilis (MICs=500 µg/ml), and virtually inactive against the gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa (MICs >1000 µg/ml). The ethanol:water extracts showed higher antimicrobial activity as compared to aqueous extracts. Based on this finding, the ethanol:water extract of P. guajava leaves was fractionated on silica gel column chromatography in a bioassay-guided fractionation affording flavonoid mixture, triterpenes (alpha- and beta-amyrin) and sterol (beta-sitosterol). Flavonoid mixture showed good activity on S. aureus with MIC of 25 µg/ml. beta-sitosterol was inactive for all the bacteria tested.
Heterotrophic succession in carrion arthropod assemblages
Authors: Moura Mauricio Osvaldo , Monteiro-Filho Emygdio Leite de Araújo , Carvalho Claudio José Barros de
Published: December 2006

Investigations were conducted on carrion attendant insects succession at two contrasting sites to determine if it was a discrete process or not. The visitation pattern of species revealed that saprophagous and predator species had complementary patterns of arrival and that percentage of reoccurring taxa ranged between 40 and 46%, except during winter when it reached 96%. The forested site always presented a higher richness than urban site, and at both the sites the tendency of species increase showed an exponential growth and then a decline. The arriving pattern was clumped in the earlier decompositional stages. At both the sites no clear boundaries were found between the decomposition stages, thus suggesting a continuous process and also suggesting that the facilitation was not the process generating the observed pattern.
Evaluation of nutrient supplementation to charcoal-treated and untreated rice straw hydrolysate for xylitol production by Candida guilliermondii
Authors: Mussatto Solange Inês , Roberto Inês Conceição
Published: December 2006

Xylitol was produced by Candida guilliermondii from charcoal-treated and untreated rice straw hemicellulosic hydrolysate with or without nutrients (ammonium sulphate, calcium chloride, rice bran extract). Both, xylitol yield and volumetric productivity decreased significantly when the nutrients were added to treated and untreated hydrolysates. In the treated hydrolysate, the efficiency of xylose conversion to xylitol was 79% when the nutrients were omitted. The results demonstrated that rice straw hemicellulosic hydrolysate treated with activated charcoal was a cheap source of xylose and other nutrients for xylitol production by C. guilliermondii. The non-necessity of adding nutrients to the hydrolysate media would be very advantageous since the process becomes less costly.
Cytogenetic analysis of the neotropical spider Nephilengys cruentata (Araneomorphae, tetragnathidae): standard staining, NORs, C-bands and base-specific fluorochromes
Authors: Araújo D. , Cella D. M. , Brescovit A. D.
Published: December 2006

The aim of this work is to characterize Nephilengys cruentata in relation to the diploid number, chromosome morphology, type of sex determination chromosome system, chromosomes bearing the Nucleolar Organizer Regions (NORs), C-banding pattern, and AT or GC repetitive sequences. The chromosome preparations were submitted to standard staining (Giemsa), NOR silver impregnation, C-banding technique, and base-specific fluorochrome staining. The analysis of the cells showed 2n = 24 and 2n = 26 chromosomes in the embryos, and 2n = 26 in the ovarian cells, being all the chromosomes acrocentric. The long arm of the pairs 1, 2 and 3 showed an extensive negative heteropycnotic area when the mitotic metaphases were stained with Giemsa. The sexual chromosomes did not show differential characteristics that allowed to distinguish them from the other chromosomes of the complement. Considering the diploid numbers found in N. cruentata and the prevalence of X1X2 sex determination chromosome system in Tetragnathidae, N. cruentata seems to possess 2n = 24 = 22 + X1X2 in the males, and 2n = 26 = 22 + X1X1X2X2 in the females. The pairs 1, 2 and 3 showed NORs which are coincident with the negative heteropycnotic patterns. Using the C-banding technique, the pericentromeric region of the chromosomes revealed small quantity or even absence of constitutive heterochromatin, differing of the C-banding pattern described in other species of spiders. In N. cruentata the fluorochromes DAPI/DA, DAPI/MM and CMA3/DA revealed that the constitutive heterochromatin is rich in AT bases and the NORs possess repetitive sequences of GC bases.
The expression of an intraspecific aggressive reaction in the face of a stressor agent alters the immune response in rats
Authors: Barreto-Medeiros J. M. , Feitoza E. G. , Magalhães K. , da Silva R. R. , Manhães-de-Castro F. M. , Manhães-de-Castro R. , De-Castro C. M. M. B.
Published: December 2006

The repercussion on the immune response of the expression of intraspecific aggressiveness in the face of a stressor agent was investigated in rats. Ninety-day-old animals were divided into three groups: the control group (only immunological measurements were performed), the foot-shock (FS) (animals individually receiving FS), and the intraspecific aggressive response (IAR) group (animals receiving FS and presenting IAR). For immunological measurements, blood samples were collected promptly at 7 and 15 days after FS or IAR. The FS reduced the total leukocyte amount presented. However, aggressiveness triggered not only reduction of the leukocytes, but also lymphocyte decrease and neutrophil increase. Moreover, an elevation in total leukocytes associated with an increase in the humoral immune response was also observed one week after IAR. In this study, the expression of intraspecific aggressiveness in the face of a stressor seemed to activate the immune system and to potentiate the antigen specific humoral response.
Meals for two: foraging activity of the butterflyfish Chaetodon Striatus (perciformes) in southeast Brazil
Authors: Bonaldo R. M. , Krajewski J. P. , Sazima I.
Published: December 2006

The banded butterflyfish (Chaetodon striatus) from the tropical and subtropical western Atlantic is a territorial, diurnal forager on benthic invertebrates. It is usually seen moving singly or in pairs, a few meters above the sea floor. We studied the foraging activity of C. striatus on rocky reefs in southeastern Brazil. This fish spent about 11 h and 30 min per day on feeding activities, and preferred colonies of non-scleratinian anthozoans over sandy and rocky substrata while foraging. The lowest feeding rates were recorded in the early morning and late afternoon, but we found no further differences between feeding rates throughout the day. We also found no differences between the feeding rates of paired and single individuals.
Malacological assessment and natural infestation of Biomphalaria straminea (Dunker, 1848) by Schistosoma mansoni (Sambon, 1907) and Chaetogaster limnaei (K. von Baer, 1827) in an urban eutrophic watershed
Authors: Callisto M. , Moreno P. , Gonçalves J. F. Jr. , Ferreira W. R. , Gomes C. L. Z.
Published: December 2006

The objective of this study was to perform a malacological assessment at the Ibirité reservoir watershed in the metropolitan region of Belo Horizonte (Minas Gerais) and to evaluate the natural infestation rate of Biomphalaria straminea (Gastropoda: Planorbidae)by Schistosoma mansoni (Platyhelminthes: Trematoda) and Chaetogaster limnaei (Oligochaeta: Naididae). The samples were collected from July to August 2002. The B. straminea individuals collected were kept in the laboratory; the natural infestation rate by S. mansoni and C. limnaei was assessed weekly. The malacological assessment identified fivemollusk species present in the Ibirité reservoir watershed: B. straminea, Physa marmorata, Lymnea sp., Melanoides tuberculatus,and Pomacea austrum. Laboratory observations showed that the B. straminea individuals were infected by C. limnaei rather than S. mansoni. Although there was no infection of B. straminea by S. mansoni,presence of B. straminea in itself merits close attention due to possible risk of human schistosomiasis by the local population.
Morphological changes of Sertoli cells during the male reproductive cycle of the teleost Piaractus mesopotamicus (Holmberg, 1887)
Authors: Cruz-Landim C. , Abdalla F. C. , Cruz-Höfling M. A.
Published: December 2006

An investigation of the histological and ultrastructural changes of Sertoli cells during the male reproductive cycle in Piaractus mesopotamicus was made. The results showed that the Sertoli cell development is closely related with germ cell maturation. Therefore, these cells may have some role in germ cell maturation during the reproductive cycle of this species, whether in forming a tissue framework for the developing spermatogenic cysts, aiding in testes reorganization for a new reproductive cycle, in addition to other possible functions discussed in the text.
Priority areas for anuran conservation using biogeographical data: a comparison of greedy, rarity, and simulated annealing algorithms to define reserve networks in Cerrado
Authors: Diniz-Filho J. A. F. , Bini l. M. , Bastos R. P. , Vieira C. M. , Vieira L. C. G.
Published: December 2006

Spatial patterns in biodiversity variation at a regional scale are rarely taken into account when a natural reserve is to be established, despite many available methods for determining them. In this paper, we used dimensions of occurrence of 105 species of Anura (Amphibia) in the cerrado region of central Brazil to create a regional system of potential areas that preserves all regional diversity, using three different algorithms to establish reserve networks: "greedy", rarity, and simulated annealing algorithms. These generated networks based on complementarity with 10, 12, and 8 regions, respectively, widely distributed in the biome, and encompassing various Brazilian states. Although the purpose of these algorithms is to find a small number of regions for which all species are represented at least once, the results showed that 67.6%, 76.2%, and 69.5% of the species were represented in two or more regions in the three networks. Simulated annealing produced the smallest network, but it left out three species (one endemic). On the other hand, while the greedy algorithm produce a smaller solution, the rarity-based algorithm ensured that more species were represented more than once, which can be advantageous because it takes into consideration the high levels of habitat loss in the cerrado. Although usually coarse, these macro-scale approaches can provide overall guidelines for conservation and are useful in determining the focus for more local and effective conservation efforts, which is especially important when dealing with a taxonomic group such as anurans, for which quick and drastic population declines have been reported throughout the world.
Dynamics of extinction in coupled populations of the flour beetle Tribolium castaneum
Authors: Godoy W. A. C. , Costa M. I. S.
Published: December 2006

In this study we analyzed the effect of migration on the persistence time of coupled local populations of Tribolium in different environments. Four treatments were set up to compare different levels of environmental heterogeneity. We established high, low, moderate, and no heterogeneity. These levels were estimated by the different amounts of food offered to each population. To investigate how risk spreading works, a stochastic model for two subpopulations was employed. The high heterogeneity treatment resulted in the longest persistence, even though survival analysis revealed no significant difference among treatments. The magnitude of differences in growth rates among subpopulations is probably associated with persistence.
Incubation and rearing-effort partitioning of wing-banded hornero Furnarius figulus (Passeriformes: Furnariidae)
Authors: Lagos A. R. , Marques R. V. , Moreno A. B. , Silva K. V. K. A. , Alves M. A. S.
Published: December 2006

We studied incubation and feeding rates in two of five broods in two oven nests of Furnarius figulus at Lagoa Rodrigo de Freitas. During incubation, the number of visits and time spent in the nest did not differ between the adults. The number of feeding visits was significantly different between members of the breeding pair of the first but not of the second nest. Nestlings received arthropods, fishes, and larvae in the first nest and, in the second, arthropods, larvae, and fruits. The nestlings stayed about 23 days in the nests.
Metabolic adjustments during semi-aestivation of the marble swamp eel (Synbranchus marmoratus, Bloch 1795) - a facultative air breathing fish
Authors: Moraes G. , Altran A. E. , Avilez I. M. , Barbosa C. C. , Bidinotto P. M.
Published: December 2006

Metabolic changes, principally in intermediary metabolism and nitrogen excretion, were investigated in the marble swamp eel (Synbranchus marmoratus) after 15 and 45 days of artificially induced semi-aestivation. Glucose, glycogen, lactate, pyruvate, free amino acids, triglycerides, ammonia, urea, and urate contents were determined in liver, kidney, white muscle, heart, brain, and plasma. Lactate dehydrogenase, glutamate dehydrogenase, malate dehydrogenase, aspartate amino transferase, alanine amino transferase, glutamine synthase, ornithine carbamoyl transferase, and arginase enzymes were assayed. The teleost S. marmoratus maintained initial energetic demands by lipid oxidation. The course of normal oxidative processes was observed through tissue enzyme profiles. After the lipid stores were exhausted, the fish consumed body proteins. Constant values of hematocrit during induced semi-aestivation suggested that the water balance remained normal. Therefore, the surrounding water was probably did not trigger the semi-aestivation in this teleost. Decrease of ammonia and increase of renal urea synthesis after 45 days of semi-aestivation led to the assumption that an alternative form of eliminating ammonia exists. Metabolic changes entailed by starvation were proposed to explain the biosynthesis of small molecules involved in the semi-aestivation of S. marmoratus.
The nutritional status of zooplankton in a tropical reservoir: effects of food quality and community structure
Authors: Pinto-Coelho R. M. , Giani A. , Morais-Jr. C. A. , Carvalho-Jr. E. R. , Bezerra-Neto J. F.
Published: December 2006

The temporal variability of energetic reserves of zooplankton in the eutrophic Pampulha reservoir was investigated during two successive annual cycles. The effects of dominance of large filter-feeding cladocerans (Daphnia) and the occurrence of massive blooms of the cyanobacteria Microcystis on the energetic reserves of zooplankton were tested. This study showed that phytoplankton composition has a greater effect on energetic reserves of zooplankton. Some associations between lipid levels and the specific composition of zooplankton were also found. This study also demonstrated that the elementary composition of phosphorus in zooplankton can be used as an estimator of the nutritional status of zooplankton.