OpenJ-Gate
   7383 Open Access Journals
      (4337 Peer-Reviewed)
OpenJ-Gate

Quick Search |  Advanced Search |  Browse Journals: by Title |  by Publisher |  by Subject 
Anais da Academia Brasileira de Ciências  [Peer Reviewed]
(Published By: Academia Brasileira De Ciências)
Table Of Contents
[Archives]
Currently Viewing: Vol. 82, No. 2,   Jun,      2010       
  1Can the Parasitic Fauna on Nile Tilapias be Affected by Different Production Systems?
   Author(s):Martins, Maurício L.; Azevedo, Tatiana M.P.; Ghiraldelli, Luciana; Bernardi, Neuza
  Keyword(s) :Oreochromis niloticus; fee fishing; swine dejects; Monogenoidea; Trichodina; prevalence.
  Abstract:

This study compared the parasitic fauna on Nile tilapias kept with swine dejects and tilapia from fee fishing fed commercial ration. A total of 360 fish were analyzed from August 2003 to July 2004 in a facility situated in Nova Trento, Santa Catarina, Brazil. No significant difference was observed in both systems. The parasite fauna in both systems were slightly similar, with the presence of the following parasites: Trichodina magna and T compacta (Ciliophora); Cichlidogyrus sclerosus and Cichlidogyrus sp. (Monogenoidea); and Lamproglena sp. (Lernaeidae). Parasitological analyzes did not differ among fishes kept with swine dejects and in fee fishing with commercial diet (P >0.05). The total prevalence of trichodinids in the gills of fish kept with swine dejects was 1.7% as compared to the one kept in fee fishing with commercial diet (0.6%). The Monogenoidea prevalence and mean intensity in the gills and body of fish from fee fishing was 16.5% and 2.6, and compared to other system was 13.2% and 0.8, respectively. This study showed that low stocking density and low water temperature in that region were responsible for the maintenance of good health and lower parasitism rate.

    
   
  2Combined U-Pb and Lu-Hf Isotope Analyses by Laser Ablation MC-ICP-MS: Methodology and Applications
   Author(s):Matteini, Massimo; Dantas, Elton L.; Pimentel, Marcio M.; Bühn, Bernhard
  Keyword(s) :LA-MC-ICP-MS; Lu-Hf; U-Pb; zircon; Borborema Province
  Abstract:

The Lutetium-Hafnium isotopic system represents one of the most innovative and powerful tools for geochronology and isotopic studies. Combined U-Pb and Lu-Hf in situ analyses on zircon by LA-MC-ICP-MS permit to characterize isotopically the host magma from which it crystallized furnishing significant information for sediment provenance and crustal evolution studies. In this paper e describe the Lu-Hf systematic by LA-MC-ICP-MS developed in the laboratory of Geochronology of the University of Brasilia and report the results obtained by repeated analyses of 176Hf/177Hf isotopic ratio of three zircon standards: GJ-1 = 0.282022 ± 11 (n=56), Temora 2 = 0.282693 ± 14 (n=25) and UQZ = 0.282127 ± 33 (n=11). The 176Hf/177Hf ratio (0.282352 ± 22, n=14) of gem quality zircon used as in-house standard have been also characterized. As a geological application, we analyzed two complex zircons selected from a migmatitic rocks from the Borborema Province, NE Brazil. On the basis of U-Pb and Lu-Hf data, two main crystallization events have been identified in both studied zircons. An older event at ca. 2.05 Ga recognized in the inherited cores represents a well-characterized paleoproterozoic magmatic event that affected the whole Borborema Province. A second crystallization event at ~ 575 Ma, recognized at the rims, represents a Neoproterozoic (Brazilian) high grade metamorphic-magmatic event.

    
   
  3Comparative morpho-anatomical Studies of the Lesions Caused by Citrus Leprosis Virus on Sweet Orange
   Author(s):Marques, João P.r.; Kitajima, Elliot W.; Freitas-astúa, Juliana; Appezzato-da-glória, Beatriz
  Keyword(s) :anatoy; hyperplasy; hypertrophy; traumatic gum ducts
  Abstract:

The leprosis disease shows a viral etiology and the citrus leprosis virus is considered its etiologic agent. The disease may show two types of cytopatologic symptom caused by two virus: nuclear (CiLV-N) and cytoplasmic (CiLV-C) types. The aim of this study was to compare the morpho-anatomical differences in the lesions caused by leprosis virus-cytoplasmic and nuclear types in Citrus sinensis (L.) Osbeck 'Pêra'. Leaf and fruit lesions were collected in Piracicaba/São Paulo (cytoplasmic type) and Monte Alegre do Sul/São Paulo and Amparo/São Paulo (nuclear type). The lesions were photographed and then fixed in Karnovsky solution, dehydrated in a graded ethylic series, embedded in hydroxy-ethyl methacrylate resin (Leica Historesin), sectioned (5 µm thick), stained and mounted in synthetic resin. The digital images were acquired in a microscope with digital video camera. Leaf and fruit lesions caused by the two viruses were morphologically distinct. Only the lesion caused by CiLV-N virus presented three well-defined regions. In both lesions there was the accumulation of lipidic substances in necrotic areas that were surrounded by cells with amorphous or droplets protein. Only leaf and fruit lesions caused by CiLV-N virus exhibited traumatic gum ducts in the vascular bundles.

    
   
  4Comparative Pollen Preferences by Africanized Honeybees Apis Mellifera L. of Two Colonies in Pará De Minas, Minas Gerais, Brazil
   Author(s):Luz, Cynthia F.P. Da; Bacha Junior, Gabriel L.; Fonseca, Rafael L.S. E; Sousa, Priscila R. De
  Keyword(s) :africanized Apis mellifera; Brazil; Para de Minas; pollen pellets; polliniferous flora.
  Abstract:

The aim of this study was to investigate the polliniferous floral sources used by Apis mellifera (L.) (africanized) in an apiary situated in Pará de Minas, Minas Gerais state, and evaluate the pollen prefences among the beehives. Two beehives of Langstroth type with frontal pollen trap collectors were used. The harvest was made from September 2007 to March 2008, with three samples of pollen pellets colected per month per beehive. The subsamples of 2 grams each were prepared according to the European standard melissopalynological method. A total of 56 pollen types were observed, identifying 43 genus and 32 families. The families that showed the major richness of pollen types were: Mimosaceae (8), Asteraceae (6), Fabaceae (3), Arecaceae (3), Euphorbiaceae (3), Rubiaceae (3), Caesalpiniaceae (2), Moraceae (2) and Myrtaceae (2). The most frequent pollen types (> 45%) were Mimosa scabrella, Myrcia and Sorocea. The results demonstrated a similarity regarding the preferences of floral sources during the major part of the time. There was a distinct utilization of floral sources among the pollen types of minor frequency. In spite of the strong antropic influence, the region showed a great polliniferous variety, which was an indicative of the potential for monofloral as well as heterofloral pollen production.

    
   
  5Cytogenotoxicity of Cymbopogon Citratus (DC) Stapf (lemon grass) Aqueous Extracts in Vegetal Test Systems
   Author(s):Sousa, Saulo M.; Silva, Pâmela S.; Viccini, Lyderson F.
  Keyword(s) :aqueous extract; Cybopogon citratus; cytotoxic effect; genotoxic effect; Lactuca sativa
  Abstract:

The lemon grass, Cymbopogon citratus (DC) Stapf, is an important species of Poaceae family commonly used in the folk medicine in many countries. The aim of this study was to investigate the cytotoxic and genotoxic effects of aqueous extracts from C. citratus leaves on Lactuca sativa (lettuce) root tip meristem cells by cytogenetic studies that have never been done before for lemon grass extracts. For this, lettuce seeds were treated for 72h with different concentrations of lemon grass aqueous extracts (5; 10; 20 and 30 mg/mL). The percentage of germination, root development and cellular behavior were analyzed, and the results showed that the highest concentration of aqueous extracts reduced the mitotic index, the seed germination and the root development of lettuce. The extracts have also induced chromosome aberrations and cellular death in the roots cells of L. sativa.

    
   
  6Diel Variation in Abundance and Size of the Seabob Shrimp Xiphopenaeus Kroyeri (Crustacea, Penaeoidea) in the Ubatuba Region, Southeastern Brazil
   Author(s):Simões, Sabrina M.; Costa, Rogerio C.; Fransozo, Adilson; Castilho, Antonio L.
  Keyword(s) :abundance; distribution; Penaeidae; Xiphopenaeus kroyeri
  Abstract:

The objective of the present study was to analyze diel variation in the abundance and size of the seabob shrimp Xiphopenaeus kroyeri in the Ubatuba region, state of São Paulo, during the year 2000. In each season of the year, collections were made in the day and at night on 9 transects at depths ranging from 2 to 40 m. The estimated shrimp amount was of 28,878 individuals. Although the catch rate was higher during the day (15,853 shrimp), this did not differ significantly from the catch at night (13,025). The catch rate was higher in daytime on most transects, but was higher at night at locations where fine and very fine sand predominated. The majority of juveniles were caught during the day. The mean size (CL) was 14.43 ± 4.02 mm for day and 14.82 ± 4.28 mm for night samples, and the difference was significant (Student's t-test, df = 2, 429, t = 2.27, p = 0.02). The largest individuals were caught during the night. None of the three models that have been proposed in the literature to account for differences in the diurnal catch pattern of penaeid species can be applied to X. kroyeri. Our results provide evidence that sediment type not only influenced the catch rate in the analyzed periods, but also determined which models might fit the behavior of this species.

    
   
  7Diet Influence on Egg Production of the Copepod Acartia Tonsa (Dana, 1896)
   Author(s):Teixeira, Priscila F.; Kaminski, Sonia M.; Avila, Tatiana R.; Cardozo, Alessandro P.; Bersano, José G.F.; Bianchini, Adalto
  Keyword(s) :egg production; Acartia tonsa; microalgae
  Abstract:

Egg production in the copepod Acartia tonsa was evaluated
using different densities of the microalgae Thalassiosira weissflogii,
Chaetoceros muelleri
and Isochrysis galbana. Male and female were
kept under controlled conditions (salinity 30, 20°C, photoperiod 12L:12D),
acclimated to the experimental conditions and left over a period of 24 h to
allow copulation. Algal densities tested were equivalent in biovolume and
corresponded to 0, 2.5, 5, 10, 20, 40 and 60.103
cells.mL-1 of T weissflogii. Ten acclimated female were
separated, transferred to glass bottles and exposed for further 24 h to the
corresponding experimental medium. After this period, the eggs were fixed and
counted. Copepod egg production reached a threshold value when T weissflogii,
C. muelleri
and I. galbana were supplied at 10.103,
140.103 and 640.103 cells.mL-1, respectively.
Mean egg production corresponded to 28.0 ± 0.5, 20.1 ± 1.0 and 22.0 ± 3.5
eggs.female-1 .day-1, respectively. Copepods fed T
weissflogii showed the highest mean egg production while those fed I.
galbana
reached a maximum egg production when the algae were supplied at a
density two- to fourfold higher, considering the biovolume of T
weissflogii and C. muelleri. These differences are explained
considering the different sizes of the microalgae used to feed the copepods.


    
   
  8Disector Z-axis Mechanical Method for Stereology
   Author(s):Xavier-vidal, Ricardo
  Keyword(s) :stereology; disector; optical disector; morphometry; Z-axis.
  Abstract:

The purpose of this work is to calibrate a not expensive microscope to be applied in Optical Disector estimation. The evaluation of "Z-axis" bias and the "Z-axis" calibration were made utilizing a cover slip and a "manual digimatic outside micrometer scale" (Mitutoyo, Japan). Calibrating the cover slip we performed the calibration of the "Z-axis" of a microscope. In the cover slip two lines were painted with different colors using a pen glass. A blue line was painted on the up surface and another line (red) on the bottom surface of the cover slip forming a cross. Two metal rings with one palette welded in each were adapted in the microscope. Other palette was welded in the gross focuses in order to restrict the route of the fine focuses (Z-axis study) using the two palettes fixed in both rings. Results show that 10 micrometers in "Z-axis" were equal to 3.2 micrometers in the scale of its fine focuses of the microscope. Then, a Disector of 10µm (10µm in Z-axis) is equal to 3.2 micrometers in the fine focuses of this microscope. In conclusion, "Z-axis" calibration is crucial to assure enough precision for Disector Method since the equipment can be manufactured without the ideal precision or its precision can be lost after use.

    
   
  9Erratum to "Action of Plant Proteinase Inhibitors on Enzymes of Physiopathological Importance" [An Acad Bras Cienc 81(2009): 615-621]
   Author(s):Oliva, Maria Luiza V.; Sampaio, Misako U.
  Keyword(s) :Erratum;Plants;Proteinase Inhibitors;Enzymes;Brass
    
   
  10Histological Modifications of the Rat Prostate Following Transection of Somatic and Autonomic Nerves
   Author(s):Diaz, Rosaura; Garcia, Luis I.; Locia, Jose; Silva, Milagros; Rodriguez, Sara; Perez, Cesar A.; Aranda-abreu, Gonzalo E.; Manzo, Jorge; Toledo, Rebeca; Hernandez, Maria Elena
  Keyword(s) :pelvic nerve; hypogastric nerve; genitofemoral nerve; scrotal nerve
  Abstract:

It is known that hormones influence significantly the prostate tissue. However, we reported that mating induces an increase in androgen receptors, revealing a neural influence on the gland. These data suggested that somatic afferents (scrotal and genitofemoral nerves) and autonomic efferents (pelvic and hypogastric nerves) could regulate the structure of the prostate. Here we assessed the role of these nerves in maintaining the histology of the gland. Hence, afferent or efferent nerves of male rats were transected. Then, the ventral and dorsolateral regions of the prostate were processed for histology. Results showed that afferent transection affects prostate histology. The alveoli area decreased and increased in the ventral and dorsolateral prostate, respectively. The epithelial cell height increased in both regions. Efferent denervation produced dramatic changes in the prostate gland. The tissue lost its configuration, and the epithelium became scattered and almost vanished. Thus, afferent nerves are responsible for spinal processes pertaining to the trophic control of the prostate, activating its autonomic innervation. Hence, our data imply that innervation seems to be synergic with hormones for the healthy maintenance of the prostate. Thus, it is suggested that some prostate pathologies could be due to the failure of the autonomic neural pathways regulating the gland.

    
   
  11In Vitro and in Vivo Antiproliferative Activity of Calotropis Procera Stem Extracts
   Author(s):Magalhães, Hemerson I.F.; Ferreira, Paulo M.P.; Moura, Eraldo S.; Torres, Márcia R.; Alves, Ana P.N.N.; Pessoa, Otília D.L.; Costa-lotufo, Letícia V.; Moraes, Manoel O.; Pessoa, Cláudia
  Keyword(s) :antimitotic; antiproliferative; Calotropis procera; Sarcoma 180 tumor; stem extracts
  Abstract:

The cytotoxic potential of stem organic extracts from Calotropis procera (Asclepiadaceae) was firstly evaluated against cancer cell lines by MTT assay. Subsequently, samples considered cytotoxic were tested for antimitotic activity on sea urchin egg development and for in vivo antiproliferative activity in mice bearing Sarcoma 180 tumor. Among the five extracts (hexane, dichloromethane, ethyl acetate, acetone and methanol), ethyl acetate and acetone extracts displayed higher cytotoxic potential against tumor cells, with IC50 ranging from 0.8 to 4.4 µg/mL, while methanolic extract was weakly cytotoxic. Cytotoxic extracts also exhibited cell division inhibition capacity by antimitotic assay, revealing IC50 values lower than 5 µg/mL. In the in vivo antitumor assessments, ethyl acetate- and acetone-treated animals showed tumor growth inhibition ratios of 64.3 and 53.1%, respectively, with reversible toxic effects on liver and kidneys. Further studies are in progress in order to identify C. procera cytotoxic compound(s) and to understand the mechanism of action responsible for this tumor-decreasing potential.

    
   
  12Influence of Accumulation of Heaps of Steel Slag on the Environment: Determination of Heavy Metals Content in the Soils
   Author(s):Garcia-guinea, Javier; Correcher, Virgilio; Recio-vazquez, Lorena; Crespo-feo, Elena; Gonzalez-martin, Rafael; Tormo, Laura
  Keyword(s) :EDS; ESEM; metal contamination; steel slag; TL; XRD; XRF
  Abstract:

The presence of high level of heavy metals involves a human healthy
risk that could induce chronic diseases. This work reports on the metal
contamination due to heaps of steel-slag accumulated during more than 40 years
in allotments and industrial areas in the southern part of Madrid (Spain).
Several slag and soil samples were collected in an area of 10 km2 and
characterized by different conventional (XRD and XRF) and no so common methods
(ESEM, thermoluminescence and EDS-WDS). The analysis reveal the presence of: (i)
important amounts of Fe (43%), Mg (26%), Cr (1.1%), Mn (4.6%), S (6.5%) in the
form of Fe-rich slag phases (wustite, magnetite...), Si and Ca-rich phases
(larnite, ghelenite...), Cr (chromite), Mn (bustamite) and graphite, (ii) traces
of some other contaminants such as Cr (7700 ppm), Zn (3500 ppm), Ba (3000 ppm),
Pb (700 ppm) or Cu (500 ppm) on pathway soil samples that come from the steel
slag, and (iii) Co (13 ppm), Pb (78 ppm) and V (54 ppm) in farmland soil
samples. Although the existing heavy metals content is not appropriate for the
current use, the extremely high metal contamination of the surrounding areas is
more worrying. The properties of the soil farmlands (pH circa 7, 13% of clay,
mainly illite, and 1-4% of organic matter content) show suitable conditions for
the retention of cationic metals, but further studies on the movilization of
these elements have to be performed to determine the possibility of severe human
health risks. This sort of study can provide useful information for the
politicians regarding the appropriate use of the territory to prevent possible
health hazard for the population.


    
   
  13Influence of Natural Settlement Cues on the Metamorphosis of Fiddler Crab Megalopae, Uca Vocator (Decapoda: Ocypodidae)
   Author(s):Simith, Darlan J.B.; Diele, Karen; Abrunhosa, Fernando A.
  Keyword(s) :conspecific 'odours'; fiddler crab; megalopa; metamorphosis; settlement; Uca vocator
  Abstract:

Megalopae of many decapod crab species accelerate their development time to metamorphosis (TTM) when exposed to natural physical and/or chemical cues characteristic of the parental habitat. In the present study, the influence of natural settlement cues on the moulting rates and development TTM in megalopae of the fiddler crab Uca vocator was investigated. The effects of mud from different habitats (including well-preserved and degraded-polluted mangrove habitats) and conspecific adult 'odours' (seawater conditioned with crabs) on the induction of metamorphosis were compared with filtered pure seawater (control). 95 to 100% of the megalopae successfully metamorphosed to first juvenile crab stage in all treatments, including the control. However, the development TTM differed significantly among treatments. Settlement cues significantly shortened development, while moulting was delayed in their absence. The fact that megalopae responded to metamorphosis-stimulating cues originating from both adult and non-adult benthic habitats demonstrates that settlement in this species may occur in a wider range of habitats within the mangrove ecosystem, including impacted areas.

    
   
  14Isoetes Pedersenii, a New Species from Southern South America
   Author(s):Macluf, Cecilia; Meza Torres, Esteban I.; Solís, Stella M.
  Keyword(s) :Argentina; Corrientes; Isoetes; Lycophyta; new species
  Abstract:

The name Isoetes pedersenii H.P. Fuchs (Lycophyta), a species known only from the Mburucuyá National Park, Corrientes, Argentina, is validated. Observations were carried out on herbarium material with stereoscopic, light and scanning electron microscopes. The species is described and typified. A diagnosis and discussion about its distribution and its relationship with the morphology of other species of Isoetes are provided.

    
   
  15Lower Nappe Aeration in Smooth Channels: Experimental Data and Numerical Simulation
   Author(s):Arantes, Eudes J.; Porto, Rodrigo M.; Gulliver, John S.; Lima, Alberto C.M.; Schulz, Harry E.
  Keyword(s) :spillway aerators; air entrainment; air-water flows; multiphase flows.
  Abstract:

Bed aerators designed to increase air void ratio are used to prevent cavitation and related damages in spillways. Air entrained in spillway discharges also increases the dissolved oxygen concentration of the water, which can be important for the downstream fishery. This study considers results from a systematic series of measurements along the jet formed by a bed aerator, involving concentration profiles, pressure profiles, velocity fields and corresponding air discharges. The experimental results are, then, compared, with results of computational fluid dynamics (CFD) simulations with the aim of predicting the air discharge numerically. Comparisons with jet lengths and the air entrainment coefficients from the literature are also made. It is shown that numerical predictive tools furnish air discharges comparable to measured values. However, if more detailed predictions are desired, verification experiments are still necessary.

    
   
  16Model of Wetland Development of the Amapá Coast during the Late Holocene
   Author(s):Guimarães, José T.F.; Cohen, Marcelo C.L.; França, Marlon C.; Lara, Rúben J.; Behling, Hermann
  Keyword(s) :Amazon river; climatic changes; mangrove; palynology; sea-level
  Abstract:

The modern vegetation types, sedimentary sequences, pollen records and radiocarbon dating obtained from three sediment cores from Calçoene Coastal Plain were used to provide a palaeoecological history during the late Holocene of Amapá coastal wetland according to flood regime, sea-level and climatic changes. Based on these records, four phases of vegetation development are presented and they probably reflect the interaction between the flow energy to the sediment accumulation and the brackish/freshwater influence in the vegetation. This work suggests interchanges among time periods characterized by marine and fluvial influence. The longitudinal profile did not reveal the occurrence of mangrove in the sediment deposited around 2100 yr B.P. During the second phase, the mud progressively filled the depressions and tidal channels. The mangrove probably started its development on the channel edge, and the herbaceous field on the elevated sectors. The third phase is characterized by the interruption of mangrove development and the increase of "várzea" vegetation that may be due to the decrease in porewater salinity related to a decrease in marine water influence. The last phase is represented by the mangrove and "várzea" increase. The correlation between current patterns of geobotanical unit distribution and palaeovegetation indicates that mangrove and "várzea" forests are migrating over the herbaceous field on the topographically highest part of the studied coast, which can be related to a relative sea-level rise.

    
   
  17Morphology and Ultrastructure of Megaspores and Microspores of Isoetes Sehnemii Fuchs (Lycophyta)
   Author(s):Macluf, Cecilia; Morbelli, Marta; Giudice, Gabriela
  Keyword(s) :Lycophyta; Isoetes; Brazil; spores; ultrastructure; sculpture; Palynology
  Abstract:

The morphology and wall ultrastructure of megaspores and microspores of Isoetes sehnemii that grows in Brazil were analyzed as part of the study of the Isoetaceae present in Southern South America. The observations were performed with light, scanning and transmission electron microscopes. The megaspores are trilete, 350-450µm in equatorial diameter. The surface is reticulate. In section, the sporoderm is 100µm thick including the ornamentation. The wall is composed of a siliceous perispore, which consists of short fused flatten, elements forming a three-dimensional mesh. The exospore has two zones of different structure. The endospore is fibrillar. The microspores are monolete, 21-27µm in equatorial diameter. The sporoderm is composed of a sporopollinic rugulate perispore. A space between the paraexospore and the exospore is evident. The exospore is compact. The endospore is fibrillar. The ultrastructural analysis akes hoologies evident concerning structure and organization of the layers belo the perispore in both spore types. A possible similarity and stability in the ultrustructure of the present spores and fossils could be also inferred. In addition, there would be a correlation among the plant habitat, the spore ornamentation and the geographic distribution.

    
   
  18Noninvasive Method for Electrocardiogram Recording in Conscious Rats: Feasibility for Heart Rate Variability Analysis
   Author(s):Pereira-junior, Pedro P.; Marocolo, Moacir; Rodrigues, Fabricio P.; Medei, Emiliano; Nascimento, José H.M.
  Keyword(s) :electrocardiography; heart rate variability; methodology; noninvasive; rat.
  Abstract:

Heart rate variability (HRV) analysis consists in a well-established tool for the assessment of cardiac autonomic control, both in humans and in animal models. Conventional methods for HRV analysis in rats rely on conscious state electrocardiogram (ECG) recording based on prior invasive surgical procedures for electrodes/transmitters implants. The aim of the present study was to test a noninvasive and inexpensive method for ECG recording in conscious rats, assessing its feasibility for HRV analysis. A custom-made elastic cotton jacket was developed to fit the rat's mean thoracic circumference, with two pieces of platinum electrodes attached on its inner surface, allowing ECG to be recorded noninvasively in conscious, restrained rats (n=6). Time- and frequency-domain HRV analyses were conducted, under basal and autonomic blockade conditions. High-quality ECG signals were obtained, being feasible for HRV analysis. As expected, mean RR interval was significantly decreased in the presence of atropine (p <0.05) and increased in the presence of propranolol (p<0.001). Also, reinforcing the reliability of the method, low- and high-frequency HRV spectral powers were significantly decreased in the presence of propranolol (p <0.05) and atropine (p< 0.001), respectively. In summary, the present work describes a novel, inexpensive and noninvasive method for surface ECG recording in conscious rats.

    
   
  19On Persistently Positively Expansive Maps
   Author(s):Arbieto, Alexander
  Keyword(s) :positively expansive maps; expanding maps.
  Abstract:

In this paper, we prove that any C1-persistently positively expansive map is expanding. This improves a result due to Sakai (Sakai 2004).

    
   
  20Palynological Analysis of Sphaeropteris Gardneri (Cyatheaceae, Pteridophyta)
   Author(s):Marquez, Gonzalo J.; Morbelli, Marta A.; Giudice, Gabriela E.
  Keyword(s) :Sphaeropteris; spores; morphology; ultrastructure.
  Abstract:

The spore morphology and wall ultrastructure of Sphaeropteris gardneri (Hook.) R.M. Tryon from Brazil were analyzed with LM, SEM and TEM. The spores are trilete with an ornamentation formed of short low ridges with spines in their margins. The exospore is 2.5µm thick, two- layered in section and single or branched channels are present. The perispore is 1.2µm thick and two-layered. The inner layer has three strata: the inner stratum is formed of a network of branched and fused threads, the middle stratum has threads with a radial orientation and in the outer stratum thin, dark fibres are immersed in a less dense contrasted matrix. The outer layer of the perispore is the one that forms the echinate-ridges and is constituted of threads arranged in a compact way. Globules of different sizes are observed on the surface. The differences found in the perispore ornamentation and ultrastructure in Alsophila, which was previously studied, and those of Sphaeropteris, show a tendency to wall complexity.

    
   
  21Seasonal Effects of Wastewater to the Water Quality of the Caeté River Estuary, Brazilian Amazon
   Author(s):Pereira, Luci C.C.; Monteiro, Marcela C.; Guimarães, Danielly O.; Matos, Jislene B.; Costa, Rauquírio M. Da
  Keyword(s) :Equatorial estuary; temporal variation; eutrophication; northern Brazil
  Abstract:

Bragança's socioeconomic situation is highly dependent on estuarine and marine biological resources that are influenced by tidal cycles and climatology. Field measurements (hydrological, hydrodynamic and microbiological variables) were taken in the most urbanized zone from Caeté estuary to characterise the quality of the local environment. During the dry period, the estuary was more eutrophic and presented the highest temperature (30.5 °C in Oct./06), salinity (17 psu in Feb./07), pH (8.24 in Feb./07) and fecal coliform (> 1000 MPN/100 ml in Dec./06 and Feb./07) values. The phytoplankton Cyclotella meneghiniana, Coscinodiscus centralis and other r-strategist species were observed. The lack of basic hydric canalization was responsible for the local contamination, especially during the dry period when more concentrated wastewater from the city was emitted into the estuary, showing the human influence on the reduction of local estuarine water quality. In Bragança, the fishery is considered one of the main economic activities so, this contamination is worrisome because a large part of the local economy depends on biological resources and, thus, the contamination could negatively affect the environmental health of this Amazon ecosystem.

    
   
  22Spatial-temporal Distribution of fire-protected Savanna Physiognomies in Southeastern Brazil
   Author(s):Pinheiro, Marcelo H.O.; Azevedo, Thiago S. De; Monteiro, Reinaldo
  Keyword(s) :cerrado; fire suppression; geostatistics; savanna dynamics.
  Abstract:

The analysis of the influence of edaphic finer textures, as a facilitating factor for the expansion of forest formations in the absence of fire, was possible thanks to rare characteristics found in a savanna fragment located in the State of São Paulo, Brazil. The total suppression of fire for over four decades, and the occurrence of two savanna physiognomies, cerrado sensu stricto and cerradão, allowed the conduction of this study based on the hypothesis that cerradão, a physiognomy of forest aspect consisting of fire-sensitive tree and shrubs species, is favored by fire absence and higher soil hydric retention capacity. Edaphic samples were collected from a regular grid of 200 m2 for the production of isopletic maps of the distribution of clay, fine sand, coarse sand and silt edaphic textures by the geostatistic method of ordinary kriging. Changes in the areas occupied by both savanna physiognomies, defined on the basis of aerial photographs taken over a period of 43 years, were assessed through mean variation rates. Besides corroborating the hypothesis of edaphic hydric retention as a facilitating factor for the expansion of forest physiognomies in savanna areas, we were able to infer the positive influence of higher precipitation on the increase in cerradão expansion rates.

    
   
  23Stress and Sleep Quality in High School Brazilian Adolescents
   Author(s):Mesquita, Gema; Reimão, Rubens
  Keyword(s) :sleep; sleep disorders; stress; sleep deprivation; psychological symptoms.
  Abstract:

OBJECTIVE: The objective of the present study is to analyze the effect of stress on sleep quality in a group of adolescents. METHOD: Two high schools in Alfenas, southern Minas Gerais State, Brazil, were chosen to participate in the study. The sample consisted of both genders (n=160) with 65.63% females. The age range of participants was 15 to18 years. The Pittsburgh Sleep Quality Index (PSQI) was applied for collection of data to quantify sleep quality. The Lipp Inventory of Stress Symptoms that objectively identifies symptoms of stress was applied. RESULTS: It was observed that 23.53% of stressed students and 45.33% of unstressed ones sleep well; 76.47% of stressed pupils and 54.67% of those unstressed do not sleep well. With regard to school performance, a mean of 0.65 was found for stressed students and 0.60 for those without stress, Mann-Whitney (p=0.0596). CONCLUSION: Stress contributed to raising the percentage of poor sleepers, as ell as increasing ean school performance.

    
   
  24Structure and Ontogeny of the Pericarp of Six Eupatorieae (Asteraceae) with Ecological and Taxonomic Considerations
   Author(s):Marzinek, Juliana; Oliveira, Denise M.T.
  Keyword(s) :anatomy; Asteraceae; carpopodium; fruit; pappus; phytomelanin
  Abstract:

The ontogeny of cypselae and their accessory parts were examined using light and scanning electron microscopy for the species Campuloclinium macrocephalum, Chromolaena stachyophylla, Mikania micrantha, Praxelis pauciflora, Symphyopappus reticulatus, and Vittetia orbiculata, some of these being segregated from the genus Eupatorium. A layer of phytomelanin observed in the fruit appears to be secreted by the outer mesocarp into the schizogenous spaces between the outer and inner mesocarp; its thickness was observed to vary among the different species examined. The bristles of the pappus are vascularized, except in M micrantha, and have cells that are superficially projected and arranged acropetally; in S. reticulatus some of the projections are retrorse and a fracture line on the floral disk that is only seen in this species may indicate a double dispersal process. Numerous differences observed among the cypselae examined here reinforce earlier segregations of the genus Eupatorium sensu lato.

    
   
  25Tectonic Control on the Stratigraphic Framework of Late Pleistocene and Holocene Deposits in Marajó Island, State of Pará, Eastern Amazonia
   Author(s):Rossetti, Dilce F.
  Keyword(s) :Amazonia; tectonics; Quaternary; stratigraphic framework; radiocarbon dating; sedimentation
  Abstract:

The traditional view that the Brazilian Amazonia is located in a tectonically stable area since the Cretaceous is changing in front of the increasing documentation of fault reactivations even during the Holocene. How the sedimentary record has responded to these events is an issue that remains to be approached with basis on field data. This work focuses on the stratigraphic correlation of late Quaternary deposits from eastern Marajó Island, with the goal of demonstrating the role of fault reactivation on the origin and preservation of these deposits. Despite the location in a stable platform of a continental passive margin, three studied stratigraphic units display significant vertical offsets that define two depocenters that are better explained through tectonic displacements. This interpretation is reinforced by several morphostructural features related to faults that occur between the studied drills. Without the influence of tectonics, sediment preservation in this characteristically low-lying terrain would have been negligible. The results of the present work motivate to look for other tectonically-influenced areas in Amazonia, which similarly might have acted as sites for sediment accommodation during the late Quaternary. These sedimentary records have great potential to be the source of valuable information for reconstructing Quaternary geological events in Northern Brazil.

    
   
  26The Density of Females of Palmistichus Elaeisis Delvare and LaSalle (Hymenoptera: Eulophidae) Affects their Reproductive Performance on Pupae of Bombyx Mori L. (Lepidoptera: Bombycidae)
   Author(s):Pereira, Fabricio F.; Zanuncio, José C.; Serrão, José E.; Zanuncio, Teresinha V.; Pratissoli, Dirceu; Pastori, Patrik L.
  Keyword(s) :alternative host; biological control; mass rearing; parasitism rate; parasitoids
  Abstract:

Palmistichus elaeisis Delvare and LaSalle (Hymenoptera: Eulophidae) is a gregarious and polyphagous parasitoid mainly of Lepidoptera pupae. The objective of this paper as to study the developent of parasitoid on Bombyx mori L. (Lepidoptera: Bombycidae) pupae exposed to one, nine, 18, 27, 36, 45 or 54 female P. elaeisis, respectively. The females of the parasitoid remained in contact with pupae for 24 hours in glass tubes (14.0 x 2.2 cm), packed in a climatic chamber regulated at 25 ± 2°C, 70 ± 10% relative humidity and photo phase of 12 hours. With the exception of density 1:1 (72.72%), in other densities parasitism was 100%. Adults of P. elaeisis did not emerge from pupae at densities of 1:1 and 9:1, but 100.0% of parasitoid emergence was observed at the density of 45:1 and 54.54% at 54:1. The duration of the life cycle of this parasitoid ranged from 20 to 28 days. P. elaeisis produced 49 to 589 descendants per pupa of B. mori. The sex ratio of P. elaeisis ranged from 0.93 ± 0.01 to 0.97 ± 0.01 without differences with 18, 27, 36, 45 and 54 females/host. This parasitoid should be reared with the density of 45 females per pupa of B. mori.

    
   
  27The Effect of Stress on Sleep Quality in Teenagers, the Analysis of Metal Contamination Due to Heaps of steel-slag Accumulation in Southern Madrid (Spain), and a Review of the Mechanisms of Glutamine Action during Severe Illnesses
   Author(s):Kellner, Alexander W. A.
  Keyword(s) :Sleep Quality;Teenagers;Severe Illnesses;Spain;Glutamine;Child Development;Researchers
  Abstract:

Researchers worldwide have pointed out the effects that stress produces upon the society. However, there are particular stress situations that affect the growing up of an individual. As pointed out several times in the literature, human development itself can be regarded as a source of stress, starting with the child's learning process followed by the physical and cognitive changes during the adolescence (e.g., Pereira and Tricoli 2003). But how does stress affect teenagers? More specifically, can any relation be established between stress, sleep quality and school performance?

    
   
  28The gamma-Weibull Distribution Revisited
   Author(s):Pogány, Tibor K.; Saxena, Ram K.
  Keyword(s) :gamma distribution; Weibull distribution; confluent Fox-Wright 1?0; incomplete confluent Fox-Wright 1?0.
  Abstract:

The five parameter gamma-Weibull distribution has been introduced by Leipnik and Pearce (2004). Nadarajah and Kotz (2007) have simplified it into four parameter form, using hypergeometric functions in some special cases. We show that the probability distribution function, all moments of positive order and the characteristic function of gamma-Weibull distribution of a random variable can be explicitely expressed in terms of the incomplete confluent Fox-Wright Psi-function, which is recently introduced by Srivastava and Pogány (2007). In the same time, we generalize certain results by Nadarajah and Kotz that follow as special cases of our findings.

    
   
  29Understanding the Mechanisms of Glutamine Action in Critically Ill Patients
   Author(s):Oliveira, Gisele P.; Dias, Cristina M.; Pelosi, Paolo; Rocco, Patricia R.M.
  Keyword(s) :heat shock protein; apoptosis; cytokines; glutamine
  Abstract:

Glutamine (Gln) is an important energy source and has been used as a supplementary energy substrate. Furthermore, Gln is an essential component for numerous metabolic functions, including acid-base homeostasis, gluconeogenesis, nitrogen transport and synthesis of proteins and nucleic acids. Therefore, glutamine plays a significant role in cell homeostasis and organ metabolism. This article aims to review the mechanisms of glutamine action during severe illnesses. In critically ill patients, the increase in mortality was associated with a decreased plasma Gln concentration. During catabolic stress, Gln consumption rate exceeds the supply, and both plasma and skeletal muscle pools of free Gln are severely reduced. The dose and route of Gln administration clearly influence its effectiveness: high-dose parenteral appears to be more beneficial than low-dose enteral administration. Experimental studies reported that Gln may protect cells, tissues, and whole organisms from stress and injury through the following mechanisms: attenuation of NF (nuclear factor)-kB activation, a balance between pro- and anti-inflammatory cytokines, reduction in neutrophil accumulation, improvement in intestinal integrity and immune cell function, and enhanced of heat shock protein expression. In conclusion, high-doses of parenteral Gln (>0.50 g/kg/day) demonstrate a greater potential to benefit in critically ill patients, although Gln pathophysiological mechanisms requires elucidation.

    
   
AdverTisements
AdverTisements

 
  What's New | Browser Compatibility | About Open J-Gate | Feedback | Contact                     
                                           ©Informatics India Ltd 2010