Anais da Academia Brasileira de Ciências

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December 1945

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5 Reads

C MAGARINOS TORRES

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Development of the banana plants 'Prata Anã' and 'FHIA-01' under the effect of paclobutrazol applied on the soil
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July 2009

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132 Reads

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Under some cultivation conditions, excessive growth of the pseudostem of banana plants can be considered a limiting factor, and thus, the use of growth regulators can constitute a valid alternative. This work aimed to evaluate the action of paclobutrazol on the growth of the pseudostem of banana plants and other characteristics of their development. An experiment was installed with five paclobutrazol doses (0; 0.5; 1.0; 1.5; and 2.0 g of a.i. plant-1) combined with two banana plant cultivars ('Prata Anã' and 'FHIA-01'). Paclobutrazol did not affect the number of days from planting to flowering, total leaf area and leaf emission rate. However, it increased leaf permanence on the plants and sucker number, reduced the foliar area of the leaves emitted after its application and provided an average reduction in pseudostem height of 26%.
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Fig. 4-Effect of pH on the activity of the purified β-1,3-glucanase from M. perniciosa. The pH values were adjusted with the following buffer systems: citrate (5.0-6.0), phosphate (7.0) and Tris-HCl (8.0-9.0). The enzyme activity was measured at 50 • C for 15 min.
Fig. 5-Effect of temperature on the activity of the purified β-1,3glucanase from M. perniciosa. All reactions were carried out in 0.05 mol L −1 of citrate buffer (pH 6.2) for 15 min. The temperatures tested ranged from 30-90 • C.
Fig. 6-Effect of stability of the purified β-1,3-glucanase from M. perniciosa. All reactions were carried out in 0.05 mol L −1 citrate buffer (pH 6.2) in the range of 6090 • C for 15 min. The percentage of residual β-1,3-glucanase activity was determined under standard assay conditions.
Fig. 7-The effect of KCl on β-1,3-glucanase activity in the range of 0.2-1 mol L −1. All reactions were carried out in 0.05 mol L −1 citrate buffer (pH 6.2) at 50 • C for 15 min.
Fig. 8 – The effect of NaCl on β-1,3-glucanase activity in the range of 0.2-1 mol L −1 . All reactions were carried out in 0.05 mol L −1 citrate buffer (pH 6.2) at 50 @BULLET C for 15 min. most others (Nagata et al. 1990, Fontaine et al. 1997, Bara et al. 2003, Marco and Felix 2007, Li et al. 2007), and higher in relation to T. harzianum (Théodore and Panda 1995). Murray et al. (2001) have also pointed out that the thermal stability of the T. emersonii enzyme is noteworthy because the estimated t 1/2 values at 70 @BULLET C and 80 @BULLET C were 136 min and 25 min, respectively, while 15% of the original activity remained after 15 min at 100 @BULLET C in the absence of substrate. The β-1,3-glucanase of Agaricus brasiliensis was stable up to 50 @BULLET C and showed a half-life of 30 min when incubated at 55 @BULLET C (SHU et al. 2006). Low thermal stability was found at 45, 50 and 60 @BULLET C in Trichoderma harzianum (Marco and Felix 2007), and half-life values of 55, 21.5 and 5 minutes were found for the same enzyme in Chaetomium thermophilum, when incubated at 65, 70 and 80 @BULLET C. This demonstrates the superiority of β-1,3-glucanase from M. perniciosa in comparison with the thermal stability of other fungi studied by other authors. Thus, β-1,3- glucanase could be effective at the standard temperatures typically used for industrial processes. The results of this study have shown that M. perniciosa could produce β-1,3-glucanase in the submerged culture, which contains three isoforms. The β-1,3-glu- canases showed high thermostability and increased activity in the presence of KCl, with concentrations  
Production, purification and characterization of a thermostable β-1,3-glucanase produced by Moniliophthora perniciosa

June 2011

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203 Reads

The enzyme glucanase from Moniliophthora perniciosa was produced in liquid medium and purified from the culture supernatant. A multivariate statistical approach (Response Surface Methodology - RSM) was employed to evaluate the effect of variables, including inducer (yeast extract) and fermentation time, on secreted glucanase activities M. perniciosa detected in the culture medium. The crude enzyme present in the supernatant was purified in two steps: precipitation with ammonium sulfate (70%) and gel filtration chromatography on Sephacryl S-200. The best inducer and fermentation time for glucanase activities were 5.9 g L(-1) and 13 days, respectively. The results revealed three different isoforms (GLUI, GLUII and GLUIII) with purification factors of 4.33, 1.86 and 3.03, respectively. The partially purified enzymatic extract showed an optimum pH of 5.0 and an optimum temperature of 40°C. The enzymatic activity increased in the presence of KCl at all concentrations studied. The glucanase activity was highest in the presence of 0.2 M NaCl. The enzyme showed high thermal stability, losing only 10.20% of its specific activity after 40 minutes of incubation at 90°C. A purified enzyme with relatively good thermostability that is stable at low pH might be used in future industrial applications.

Fig. 3-Mechanistic proposition of oxazole formation. 
1,4- Addition of diazomethane to a heterodiene: A direct preparation of the oxazolic ring

March 2007

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189 Reads

The reaction of naphthoquinone-oximes (3) and (4) with diazomethane yields directly, in one step, the oxazoles (5) and (6), respectively.

Fig. 1-Structures of lawsone 1 and derivatives 2-17. 
Molluscicidal activity of 2-hydroxy-[1,4] naphthoquinone and derivatives

July 2008

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448 Reads

The toxic profile of lawsone (2-hydroxy-[1,4]naphthoquinone) and a series of [1,4]naphthoquinone derivatives was evaluated against the brine shrimp Artemia salina and against the mollusk Biomphalaria glabrata, the main transmitting vector of schistosomiasis in Brazil. Of the seventeen compounds tested nine fell below the threshold of 100 microg/mL set for potential molluscicidal activity by the World Health Organization. As a general rule derivatives with non-polar substituents presented the highest molluscicidal activities. These substances showed significant toxicity in A. salina lethality bioassay.

Fig. 2-(A) Absorption spectra of DPN films with 6, 8, 10, 12, 14 and 16 layers on each side of a glass slide (-) and of DPN ([4 × 10 −6 M]) solutions (5 cm path length) in CH 3 CN (· · · ) and water (-). (B) Emission spectra of a DPN film with 16 layers on each side of a glass slide (-) and of DPN ([5 × 10 −6 M])solution in water (-). The emission spectrum of a suspension of microcrystalline N,N'-dibutyl-1,4,5,8-naphthalenediimide in water is also shown (· · · ). Spectra are normalized to I max = 1, and λ ex = 310nm in all cases. 
Zirconium phosphonate/1,4,5,8-naphthalenediimides self-assembled films

February 2000

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67 Reads

The formation and characterization of self-assembled films of zirconium phosphonate/N,N'-di(2-phosphonoethyl)-1,4,5,8-naphthalenediimide (DPN) is presented. The films were produced on glass substrates by deposition of alternating layers of Zr+4 and DPN. Films containing up to 16 layers on each side of the substrate were obtained and monitored by absorption spectroscopy and ellipsometry. When irradiated, the initially colorless films turned to a persistent pinky color reminiscent of that of DPN anion radical. These films are a promising material to the development of photovoltaic devices.




Fig. 1-Location (a) and geological map (b) of Pitinga Mining District. (modified from (a) Hartmann and Delgado 2001 and (b) Ferron et al. 2007).
Fig. 2-Petrographic features of coherent units and ignimbrites. a) subhedral hornblende rounded by thin layer of leucoxene in effusive trachyte; b) micropoikilitic texture and acicular quartz in hypabyssal rhyolite; c) flow foliation in hand-specimen of effusive rhyolite; d) interbedding of fine phaneritic to vitric layers of the foliated rhyolite; e) euhedral phenocryst rotated by flow; f) elongated vesicle along the flow foliation; g) idealized section of a pyroclastic flow unit; h) top of intermediate showing subhorizontal eutaxitic structure; i) eutaxitic texture in thin section of an ignimbrite; j) compacted vesicle filled with quartz, opaque minerals and chlorite; k) perlitic cracks in an originally glassy matrix; l) devitrification features: spherulitic intergrowing at the centre of the fiamme and axiolitic intergrowing at the edge; m) hand specimen of a ignimbrite with cognate lithic clasts; n) Y-U-shaped and bubble-wall shards within a cognate lithic clast (center-left portion).
Fig. 3-Field and petrographic characteristics of the surge deposits of the Iricoumé Group: a) outcrop A13-see Figure 5 for location; b) Sketch of outcrop A13 showing the six bedsets; c) microscopic feature showing the dominant massiveness of co-ignimbritic deposits; d) internal organization of the surge deposits; e) plane parallel stratification in weathered and fresh surface close to the boundary between sets 1 and 2; f) erosional boundary between bedsets 3 and 4; g) level of lithic fragment close to the top of the bedset 4; h) tuffaceous cognate lithic fragment with dropping feature in thin section; i) low-angle truncation between bedsets 4 and 5.
Fig. 4-Viscosity estimation for Iricoumé samples as a function of water content. Solid lines represent best fit curves.
Paleoproterozoic (~1.88Ga) felsic volcanism of the Iricoumé Group in the Pitinga Mining District area, Amazonian Craton, Brazil: Insights in ancient volcanic processes from field and petrologic data

September 2011

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322 Reads

The Iricoumé Group correspond to the most expressive Paleoproterozoic volcanism in the Guyana Shield, Amazonian craton. The volcanics are coeval with Mapuera granitoids, and belong to the Uatumã magmatism. They have U-Pb ages around 1880 Ma, and geochemical signatures of α-type magmas. Iricoumé volcanics consist of porphyritic trachyte to rhyolite, associated to crystal-rich ignimbrites and co-ignimbritic fall tuffs and surges. The amount and morphology of phenocrysts can be useful to distinguish lava (flow and dome) from hypabyssal units. The morphology of ignimbrite crystals allows the distinction between effusive units and ignimbrite, when pyroclasts are obliterated. Co-ignimbritic tuffs are massive, and some show stratifications that suggest deposition by current traction flow. Zircon and apatite saturation temperatures vary from 799°C to 980°C, are in agreement with most temperatures of α-type melts and can be interpreted as minimum liquidus temperature. The viscosities estimation for rhyolitic and trachytic compositions yield values close to experimentally determined melts, and show a typical exponential decay with water addition. The emplacement of Iricoumé volcanics and part of Mapuera granitoids was controlled by ring-faults in an intracratonic environment. A genesis related to the caldera complex setting can be assumed for the Iricoumé-Mapuera volcano-plutonic association in the Pitinga Mining District.

Kinetic study on beta-lactamase from Streptomyces UCSM-104

January 1983

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3 Reads

The beta-lactamase of Streptomyces UCSM-104 behaves as a penicillinase with the different substrates studied, being more active with benzylpenicillin (KM 2.6 mM) and ampicillin (KM 1.5 mM). On the other hand, it was competitively inhibited by methicillin (Ki 0.035 mM) and cloxacillin (Ki 0.35 mM) using benzylpenicillin as substrate. According to the criterion of Jack and Richmond in relation to the degree of inhibition obtained, the enzyme was found to be resistant to cloxacillin and sensible to methicillin.

Fig. 1-Oil red staining of the cells after 14 days of the beginning of adipogenic differentiation showing accumulated lipid vesicles in the cytoplasm. 
Fig. 2-A) Quantitative real time PCR showing expression of COL18A1 during human adipogenic differentiation in vitro. B) LPL was quantified as a control of the differentiation experiment and, as expected, it showed high expression levels after the beginning of the adipogenesis process. 
COL18A1 is highly expressed during human adipocyte differentiation and the SNP c.1136C>T in its "frizzled" motif is associated with obesity in diabetes type 2 patients

March 2008

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163 Reads

Collagen XVIII can generate two fragments, NC11-728 containing a frizzled motif which possibly acts in Wnt signaling and Endostatin, which is cleaved from the NC1 and is a potent inhibitor of angiogenesis. Collagen XVIII and Wnt signaling have recently been associated with adipogenic differentiation and obesity in some animal models, but not in humans. In the present report, we have shown that COL18A1 expression increases during human adipogenic differentiation. We also tested if polymorphisms in the Frizzled (c.1136C>T; Thr379Met) and Endostatin (c.4349G>A; Asp1437Asn) regions contribute towards susceptibility to obesity in patients with type 2 diabetes (113 obese, BMI > or =30; 232 non-obese, BMI < 30) of European ancestry. No evidence of association was observed between the allele c.4349G>A and obesity, but we observed a significantly higher frequency of homozygotes c.1136TT in obese (19.5%) than in non-obese individuals (10.9%) [P = 0.02; OR = 2.0 (95%CI: 1.07-3.73)], suggesting that the allele c.1136T is associated to obesity in a recessive model. This genotype, after controlling for cholesterol, LDL cholesterol, and triglycerides, was independently associated with obesity (P = 0.048), and increases the chance of obesity in 2.8 times. Therefore, our data suggest the involvement of collagen XVIII in human adipogenesis and susceptibility to obesity.

Structural studies on allergen RC-13 from Ricinus communis L.: isolation and characterization of a major glycopeptide

April 1990

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17 Reads

A glycoprotein, RC-13, isolated from Ricinus communis seeds was reduced, S-alkylated and cleaved by trypsin. The tryptic digest was fractionated by ion-exchange chromatography and a glycopeptide was isolated and purified by high-voltage paper electrophoresis. When submitted to amino acid and carbohydrate analyses this major glycopeptide showed the following chemical composition: Lys1, Asp1, Thr2, Ser4, Glu1, Pro2, Gly2, Ala2, Val2, GlcN6, Man6 and Gal8. Hydrazynolysis positioned Ser as the C-terminal residue. It is postulated that this glycopeptide belongs to the C-terminal region of the allergen.

Fractionation of castor bean allergens (CB-1A). Isolation of RC-13, a homogeneous allergenic fraction

January 1986

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9 Reads

Allergens from castor beans (CB-1A) were fractionated by ion-exchange chromatography both on CM- and SP-Sephadex, employing pH gradient. SP-Sephadex showed better results and fractionated the allergens into 7 components, eluted in a narrow pH range (5.0 - 6.6). An attempt to isolate the major acidic fraction of the group involved successive chromatographic steps on the same gel. RC-13, the isolated fraction, proved homogeneous by rechromatography on SP-Sephadex and isolectric focusing with pH range 3.0 - 10.0 polyacrylamide gel. The pl of RC-13 determined by the latter is approximately 4.2 and allergenic activity was demonstrated by heterologous passive cutaneous anaphylaxis in mice using anti-CB-1A rabbit serum.

Spatial variation in the stable isotopes of C-13 and N-15 and trophic position of Leporinus friderici (Characiformes, Anostomidae) in Corumba Reservoir, Brazil

March 2007

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57 Reads

Stable isotopes of carbon (delta13C) and nitrogen (delta15N) were used to describe sources of energy and trophic position for adult Leporinus friderici in the area of the Corumbá Reservoir, Brazil. Samples were collected from April 1999 to March 2000. Spatial variations were not identified in the isotopic composition. The maximum and minimum contribution of C4 plants calculated integrating the variation of plants and fish were 47.7% and 2.4%, respectively. Among C3 plants, periphyton presented closer isotopic values to those observed for fishes, corresponding to an important carbon source. The proportion of ingested plant item is larger in rivers upstream from the reservoir (42.7%), which justifies the smaller trophic level among there. However, in the reservoir, the ingestion of fish was 81.4%, while ingested plants contributed with 18.6%. Downstream from the dam, participation of plant item was even smaller (14.4%). Although the trophic position calculated with diet data was proportional to the one calculated with delta15N values, the former elevated the trophic level of L. friderici in the food web, because estimated trophic positions were based on fish items belonging to the 2nd (a) and to the 3rd (b) trophic levels.

Partial characterization of RC-13, a homogeneous fraction isolated from castor bean allergens (CB-1A)

October 1987

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13 Reads

Allergen RC-13's amino acid composition was determined-Lys3, His1, Arg7, Asp6, Thr2, Ser11, Glu29, Pro2, Gly7, Ala4, Cys6, Val5, Met1, Ile3, Leu3, Tyr1; 91 residues. Partial specific volume and minimum molecular weight evaluated from this composition were, respectively, 0.694 cm3/g and 10,194. SDS-polyacrylamide gel electrophoresis performed in the reduced and alkylated form of the allergen revealed a single band, suggesting the existence of only one polypeptide chain in the molecule. Results obtained for carbohydrate analysis by gas-liquid chromatography were: 22.2% galactose and 16.2% mannose--approximately 38% of neutral sugars. Employment of the amino acid methodology for analysis of amino sugars revealed two residues of glucosamine per molecule of the allergen. Hydrolyses with trypsin, alpha-chymotrypsin and type VII protease were tested for sequence studies. Trypsin was considered a suitable enzyme for such purpose.

Fig. 1 – (A) Bi-dimensional soil horizon distribution within the forest transect (FT) segment determined with the aid of morphological and micro-morphological analyses. The terms A1, A2, 2AB, BA, Bg, and Bw represent designations for horizons and other soil layers. (B) 137 Cs inventories of the points along the FT segment. The dot line represents the inventory value at the reference site. (C) Values of δ 13 C of the points along the FT segment.  
Fig. 2 – Average soil erosion (E) (+) and deposition (D) (–) rates as a function of band widths (ST – sugarcane and FT – riparian forest segments) obtained using the 137 Cs technique.  
Fig. 3 – Contribution of the sugarcane carbon (%SC) to the total soil carbon in the sugarcane transect (ST) segment and in the riparian forest transect (FT) segment.  
Riparian forest potential to retain sediment and carbon evaluated by the 137Cs fallout and carbon isotopic ratio techniques

July 2009

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87 Reads

Riparian forests can provide an important service for aquatic ecosystems by sequestering hillslopederived sediments. However, the width of a riparian buffer zone required to filter sediments is not yet wellunderstood. Here are used two complementary tracers to measure sediment retention. The 137Cs technique and the soil carbon isotopic ratios (delta13C) are utilized to investigate sediment deposition and erosion rates on a slope transect cultivated with sugarcane followed by a secondary riparian forest zone in Iracemápolis, State of São Paulo, Brazil. The 137Cs technique and the delta13C analysis showed that the width of a riparian vegetation in accordance to a Brazilian Environmental Law (N masculine4.771/65) was not sufficient in trapping sediments coming from agricultural lands, but indicated the importance of these forests as a conservation measure at the watershed scale. The complementary delta13C analysis together with soil morphology aspects allowed a better interpretation of the sediment redistribution along the sugarcane and riparian forest transects.

[Application of artificial intelligence techniques in organic chemistry. Study, by computer, of NMR 13C of steroids]

July 1991

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12 Reads

This work describes the utilization of two groups of programs in searching for characteristic signals of NMR 13C of steroidal compounds. The first group of programs used data bases with the spectral data and a methodology that enables the choice and the search of substructures. The chemical shifts and multiplicities for each specific substructure are used as rules to identify different types and subtypes of steroidal compounds. The second one was built to apply the rules formulated by the first group of programs and to foresee any skeletal based on a spectral analysis.

Complete 1H and 13C NMR assignments and antifungal activity of two 8-hydroxy flavonoids in mixture

July 2007

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323 Reads

A mixture of the two new flavonols 8-hydroxy-3, 4', 5, 6, 7-pentamethoxyflavone (1) and 8-hydroxy-3, 3', 4', 5, 6, 7-hexamethoxyflavone (2) was isolated from a commercial sample of Citrus aurantifolia. An array of one- (1HNMR, {1H}-13C NMR, and APT-13C NMR) and two-dimensional NMR techniques (COSY, NOESY, HMQC and HMBC) was used to achieve the structural elucidation and the complete 1H and 13C chemical shift assignments of these natural compounds. In addition, the antifungal activity of these compounds against phytopathogenic and human pathogenic fungi was investigated.

TL, OSL and C-14 Dating Results of the Sediments and Bricks from Mummified Nuns' Grave

May 2012

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151 Reads

This paper presents the results of TL and OSL dating of soil and fragments of bricks from a grave, which was occupied by two mummified nuns, found at "Luz" Monastery, located in the state of São Paulo, Brazil. The TL and OSL ages were compared to C-14 dating ones obtained from bone collagens of the mummies. The majority of the ages is related to the eighteenth century. The gamma-ray spectroscopy was used to evaluate natural radioisotope concentrations in the samples, and by using these concentrations the annual dose rates, from 3.0 to 5.3 Gy/kyr, were obtained. Neutron activation analysis was performed and the radioisotope contents results are in agreement with those obtained by gamma-ray spectroscopy. The contents of U, Th and Ce elements were higher than those found in usual sediments.

[Cesium-157 in milk produced on farms of the Angra dos Reis Region, RJ]

April 1985

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11 Reads

The first Brazilian Nuclear Power Plant is located in the Angra dos Reis county, about 130 km West of Rio de Janeiro. Among the radionuclides that will be released to the environment by the Nuclear Plant, tritium and radioisotopes of Cs, I, Co and Sr are the ones of greatest potential impact on the local population. During the preliminary phase of the pre-operational environmental radiological program, 137Cs resulting from nuclear explosion fallout was detected in milk samples from only one farm, among the ones included in the monitoring program. This finfing seemed odd, leading to believe on the possibility of a soil anomaly on the region, in which 137Cs would be more available for plant uptake than in normal areas, as it has been observed in some areas in various countries. Trying to explain this issue, the Radioisotopes Laboratory of the Biophysics Institute and the Radioecology Laboratory of FURNAS decided to carry on a series of analyses of 137Cs in milk, pasture and soil collected in the four farms of the program. The results demonstrated the non-existence of a soil anomaly in the region regarding the 137Cs behavior Cesium-137 concentrations in milk varied from 0.06 to 0.93 Bq/l but the differences of the average values in the four farms were not statistically significant. In one farm, occasional high peaks of 137Cs concentrations in milk were observed, which seemed to be related to the cattle management. Apparently during certain periods, the cattle grazes in sectors whose 137Cs concentrations in soil and pasture are higher than in other areas of the same farm or the region, due to the influence of micro-climate and erosion of superficial soil.

Fig. 1-TLC plate developed in ninhydrin for glycine analysis. A, B, and C are glycine samples synthesized from 50, 100, and 150 ml ammonia, respectively. Sample D refers to 15 N-enriched glycine. E and F correspond to the glycine p.a. standard. 
15N-labed glycine synthesis

October 2006

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376 Reads

This work describes a method for 15N-isotope-labeled glycine synthesis, as well as details about a recovery line for nitrogen residues. To that effect, amination of alpha-haloacids was performed, using carboxylic chloroacetic acid and labeled aqueous ammonia (15NH3). Special care was taken to avoid possible 15NH3 losses, since its production cost is high. In that respect, although the purchase cost of the 13N-labeled compound (radioactive) is lower, the stable tracer produced constitutes an important tool for N cycling studies in living organisms, also minimizing labor and environmental hazards, as well as time limitation problems in field studies. The tests were carried out with three replications, and variable 15NH3aq volumes in the reaction were used (50, 100, and 150 mL), in order to calibrate the best operational condition; glycine masses obtained were 1.7, 2, and 3.2 g, respectively. With the development of a system for 15NH3 recovery, it was possible to recover 71, 83, and 87% of the ammonia initially used in the synthesis. With the required adaptations, the same system was used to recover methanol, and 75% of the methanol initially used in the amino acid purification process were recovered.

Fig. 2-Amphisbaena fuliginosa, body annuli, Colombia-Manaus transect. 
Fig. 3-Amphisbena fuliginosa, regression of tail length on body length, ManausIquitos transect. 
Fig. 5-Summary of Figure 4 1-3. Conventions for samples as in Figure 4 1-3. Small letters to the left of the dash mean characters in which the two samples do not differ significantly; to the right of the dash, characters with significant differences. a, body annuli. b, tail annuli. c, segments to a midbody annulus. 
A second note on the geographical differentiation of Amphisbaena fuliginosa L., 1758 (Squamata, Amphisbaenidae), with a consideration of the forest refuge model of speciation

January 2003

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176 Reads

The geographical differentiation of Amphisbaena fuliginosa L. is studied with basis on 220 specimens from 99 definite and 2 generic localities, ranging from Panam to Puno in Peru and Goi s in Brasil. The pattern found is considered to support Vanzolini's 1951 scheme of five subspecies, defined by color pattern and by four meristic characters, and differentiated in consequence of Quaternary paleoecological events. Recent developments relating to models of differentiation in Quaternary tropical South America are briefly considered.


Fig. 1-Localization of cores T4 (•) and T8 (x) in the Bay of Guanabara. 
Paleoenvironment interpretation of a 1760 years B.P. old sediment in a mangrove area of the Bay of Guanabara, using pollen analysis

July 2006

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93 Reads

A sediment sample was obtained at 122 cm from the top of a drilling core in the Guapimirim mangrove, Bay of Guanabara, and analyzed using pollen analysis. This muddy core reached a sandy ground at 133 cm. 14C datation got the age of 1760 +/- 50 years B.P. The most frequent pollen grains were mangrove species of Rhizophora mangle, Laguncularia racemosa and Avicennia schaueriana. "Restinga" and tropical rain forest vegetation was recognized behind the mangrove. After the last sea transgression at 2500 years B.P., the water level lowered to its actual size, allowing the installation of this mangrove.


Fig. 1-The normal Thyrinteina arnobia female. Note wing coloration and filiform antennae. Scale bar = 0.5 cm. Fig. 2-The normal Thyrinteina arnobia male. Note wing coloration and pectinated antennae. Scale bar = 0.5 cm. Fig. 3-The Thyrinteina arnobia gynandromorph. Note the male characters (brown wings, larger eyes and pectinated antenna) on the left side and female characters (clear wings, filiform antenna and smaller eyes) on the right side. Scale bar = 0.1 cm. 
Note on gynandromorphism in the eucalyptus defoliator Thyrinteina arnobia (Stoll, 1782) (Lepidoptera : Geometridae)

July 2007

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180 Reads

The brown moth Thyrinteina arnobia (Stoll, 1872) (Lepidoptera: Geometridae) is an important pest in Brazilian eucalyptus plantations. A gynandromorph individual of T. arnobia was found in a population of this pest in a laboratory rearing and it is described.A mariposa marrom Thyrinteina arnobia (Stoll, 1872) (Lepidoptera: Geometridae) é uma praga importante em plantios de eucalipto no Brasil. Um indivíduo ginandromorfo de T. arnobia foi encontrado em uma população desta praga em criação de laboratório e descrito nesta nota.

Fig. 1-Standard curve for in vitro transcribed RNA. The standard curve was derived by linear regression including all Ct values shown in 
Limited replication of yellow fever 17DD and 17D-Dengue recombinant viruses in rhesus monkeys

July 2008

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58 Reads

For the development of safe live attenuated flavivirus vaccines one of the main properties to be established is viral replication. We have used real-time reverse transcriptase-polymerase chain reaction and virus titration by plaque assay to determine the replication of yellow fever 17DD virus (YFV 17DD) and recombinant yellow fever 17D viruses expressing envelope proteins of dengue virus serotypes 2 and 4 (17D-DENV-2 and 17D-DENV-4). Serum samples from rhesus monkeys inoculated with YFV 17DD and 17D-DENV chimeras by intracerebral or subcutaneous route were used to determine and compare the viremia induced by these viruses. Viral load quantification in samples from monkeys inoculated by either route with YFV 17DD virus suggested a restricted capability of the virus to replicate reaching not more than 2.0 log10 PFU mL(-1) or 3.29 log10 copies mL(-1). Recombinant 17D-dengue viruses were shown by plaquing and real-time PCR to be as attenuated as YF 17DD virus with the highest mean peak titer of 1.97 log10 PFU mL(-1) or 3.53 log10 copies mL(-1). These data serve as a comparative basis for the characterization of other 17D-based live attenuated candidate vaccines against other diseases.

Fig. 1-Areas of natural occurrence of Melipona scutellaris in the state of Bahia, Brazil. SPRING software v. 4.1 (Camara et al. 1996). 
Fig. 2-Occurrence boundaries for the species Melipona scutellaris in the state of Bahia considering the approximate distance between bordering municipalities. 
Fig. 3-Gradient of elevation distribution of Melipona scutellaris in the state of Bahia, Brazil. 
Areas of Natural Occurrence of Melipona scutellaris Latreille, 1811 (Hymenoptera: Apidae) in the state of Bahia, Brazil

September 2012

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91 Reads

The bee Melipona scutellaris is considered the reared meliponine species with the largest distribution in the North and Northeast regions of Brazil, with records from the state of Rio Grande do Norte down to the state of Bahia. Considering the importance of this species in the generation of income for family agriculture and in the preservation of areas with natural vegetation, this study aimed at providing knowledge on the distribution of natural colonies of M. scutellaris in the state of Bahia. Literature information, interviews with stinglessbee beekeepers, and expeditions were conducted to confirm the natural occurrence of the species. A total of 102 municipalities showed records for M. scutellaris, whose occurrence was observed in areas ranging from sea level up to 1,200-meter height. The occurrence of this species in the state of Bahia is considered to be restricted to municipalities on the coastal area and the Chapada Diamantina with its rainforests. Geographic coordinates, elevation, climate and vegetation data were obtained, which allowed a map to be prepared for the area of occurrence in order to support conservation and management policies for the species.

On clutch size and hatching success of the South American turtles Podocnemis expansa (Schweigger, 1812) and P. unifilis Troschel, 1848 (Testudines, Podocnemididae)

January 2004

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46 Reads

Data on clutch size and hatching success of P. expansa were gathered for seven beaches traditionally used by the species and re-analyzed statistically by means of regression analysis, of the number of eggs on the number of females (or nests) and of the number of young on the number of eggs. All regressions were linear, passed through the origin and had excellent fits. Average clutch size varied from 75 to 123, and presented geographic differentiation: (i) Rio Orinoco, (ii) Rio Trombetas + Rio Branco and (iii) Rio Juruá + Rio Purus. Average hatching success was ca. 83%. In P. unifilis there was also geographic variation in clutch size, the Iquitos area showing the highest values. Hatching success of P. unifilis was uniformly high: only one sample, from Iquitos, had less than 90% success. The outstanding fit of the clutch size regressions leads one to consider egg volume variability, which was found to be high in both species, in contradiction with current optimal egg size theory.

Do precipitation and food affect the reproduction of brown brocket deer Mazama gouazoubira (G. Fischer 1814) in conditions of semi-captivity?

September 2010

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70 Reads

The births of brown brocket deer ( Mazama gouazoubira) in a secondary lower montane forest called "yunga" in northwestern Argentina were compared with rainfall. Analyses were performed with rainfall and flower-fruit fall in an attempt to determine the possible importance of these seasonal variables in birthing. The births were not directly correlated with rainfall, but rather with the flower and fruit fall of exotic plant species. This may be related to favor the development of fawns, which eat the new and more digestible plant parts, accessible one month after their births.The non-seasonal births observed around the year could be related to the selection by the deer of some plant species that have been introduced into the region (Prunus, Morus and Psidium), have a longer fruiting span than the scarce native plant species.

Glucose-6-phosphate dehydrogenase of Biomphalaria glabrata (Say , 1818) (Mollusca: Pulmonata). Characterization and inheritance pattern

February 1976

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9 Reads

Glucose-6-phosphate dehydrogenase of Biomphalaria glabrata has been characterized by electrophoresis, kinetic properties and inheritance pattern. It exists as a single electrophoretic band with no polymorphism in the natural population studied during the present investigations. There are no organ-specific differences in electrophoretic pattern. The enzyme from the homogenates of various organs e.g., albumen gland, digestive gland, ovotestis and columellar muscle show similar physico-chemical parameters, such as optima for pH, NADP and glucose-6-phosphate. Incorporation of NADP is essential for maintaining the stability of the enzyme, failing which, there appear artifactual variations in electrophoretic mobility of the enzyme. The apparent lack of polymorphism in natural population of Biomphalaria glabrata has been discussed.

Biological monitoring of organochlorides using the limnic bivalves Anodontites trapesialis (Lam., 1819)

January 1992

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15 Reads

The mussel Anodontites trapesialis (Lam, 1819) was used as an indicator of organochloride pollutants in the Canoas River, located in the municipality of Mococa (21 degrees 25'08''S and 47 degrees W), State of São Paulo, Brazil. Biological monitoring was performed for one year at the site of an orange grove on the left bank of the river. Forty-five animals were placed in aluminum enclosures on the river bottom at this site and 4 animals were sacrificed for pesticide analysis at 3-month intervals, each corresponding to one season of the year. Pesticides were extracted by the method of Bedford et al., (1968), modified, and the analyses were performed by gas phase chromatography equipped with an electron capture detector. The animals were found to have been exposed to DDT, Lindane and Heptachlor. Variation in Aldrin and Dieldrin levels was not significant enough to permit inferences. Endrin was not detected in any of the analyses.

On the geographical differentiation of Gymnodactylus geckoides Spix, 1825 (Sauria, Gekkonidae): speciation in the Brazilian caatingas

January 2005

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9 Reads

The specific concept of G. geckoides was initially ascertained based on a topotypical sample from Salvador, Bahia. Geographic differentiation was studied through the analysis of two meristic characters (tubercles in a paramedian row and fourth toe lamellae) and color pattern of 327 specimens from 23 localities. It is shown that the population from the southernmost locality, Mucugê, is markedly divergent in all characters studied. A Holocene refuge model is proposed to explain the pattern. A decision about the rank to be attributed to the Mucugê population is deferred until more detailed sampling is effected and molecular methods are applied.

Figure 1 -Tube of the small intestine of D. aurita. vi-villus; mc-mucous layer; smc-submucous layer; ms-muscular; se-serous (H-E).  
Figure 2 -Submucous nervous plexus in the small intestine of D. aurita. mci-inner circular muscular layer (H-E).  
Figure 3 -Myenteric nervous plexus in the small intestine of D. aurita. mci-inner circular muscular layer; mle-external longitudinal muscular layer; se-serous (H-E).  
Figure 4 -Argirophilic endocrine cells in the mucous layer of the ileum of D. aurita  
Figure 5 -Immunoreactive endocrine cells to insulin in the mucous layer of the ileum of D. aurita  
Endocrine cells and nerve ganglia of the small intestine of the Opossum Didelphis aurita Wied-Neuwied, 1826 (Mammalia: Didelphidae)

July 2012

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118 Reads

The nervous and endocrine systems jointly control intestinal movements, secretions of their glands and also participate of the processes of nutrient digestion and absorption. Therefore, the central objective of this study was to verify the existence of a possible relationship between the number of nervous cells and ganglia of the submucosal and myenteric plexuses and the number of endocrine cells in the small intestine of adult D. aurita. The utilized staining techniques were Grimelius, modified Masson-Fontana, direct immunoperoxidase and H-E. Argyrophillic, argentaffin and insulin immunoreactive endocrine cells do not numerically vary between the initial, mid and final regions of the duodenum, jejunum and ileum (P>0.05), except for argyrophillic cells in the jejunum (P>0.05). No numerical relationship has yet been verified between the number of nerve ganglia and endocrine cells, and also between nervous and endocrine cells. We recommended the use of new immunohistochemical techniques to confirm the numerical correlation between the nervous and endocrine systems in the small intestine. The morphology and distribution of endocrine cells and the nerve ganglia studied were similar to those encountered in eutherian mammals.

Figure 1-A: fish head without convexity; B: head deformity in pintados fingerlings not supplemented with vitamin. Arrows and lines in indicate deformities: lines, convex head, arrow indicates weakness and distortion of the fins. Scale bar = 1cm. 
Morphological deformities in the osseous structure in spotted sorubim Pseudoplatystoma coruscans (Agassiz & Spix, 1829) with vitamin C deficiency

March 2013

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114 Reads

Vitamin C is essential for fish diets because many species cannot syntethize it. This vitamin is needed for bone and cartilage formation. Moreover, it acts as antioxidant and improve the immunological system. The present work investigated the effects of vitamin C diet supplementation to spotted sorubim (Pseudoplatystoma coruscans) fingerlings by frequency of bone and cartilage deformation. Ascorbyl poliphosphate (AP) was used as source of vitamin C in the diets for spotted sorubim fingerlings during three months. Six diets were formulated: one diet control (0 mg/kg of vitamin C) and 500, 1,000, 1,500, 2,000 and 2,500 mg AP/kg diets. Fishes fed without vitamin C supplementation presented bone deformation in head and jaws, and fin fragilities. Thus, 500 mg AP/kg diet was enough to prevent deformation and the lack of vitamin C supplementation worsening the development of fingerlings.

Figure 1. Itamaracá estuarine system (Pernambuco, Brazil) showing the Catuama Inlet and the sampling stations (indicated as marked). 
Figure 2. Density of Petrolisthes armatus larvae (ind. m -3 ) at Catuama Inlet (Northeastern Brazil) during a diel cycle (between August 11 and 12, 2001). Standard deviations of the density are based on triplicate samples. 
Figure 3. Transport of Petrolisthes armatus larvae (ind. m -2 s -1 ) at Catuama Inlet (Northeastern Brazil) during a diel cycle (between August 11 and 12, 2001). Standard deviations of the transport are based on triplicate samples. Positive values indicate larval import from the shelf area, and negative values indicate larval export from the Catuama inlet to the inner shelf area. 
Abundance and instantaneous transport of Petrolisthes armatus (Gibbes, 1850) planktonic larvae in the Catuama inlet, Northeast Brazil

March 2012

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68 Reads

The influence of tidal and diel changes on the exchange of Petrolisthes armatus planktonic larvae was studied at the Catuama inlet, which represents an intermediate system of marine and estuarine environments in the Northeast Brazil. To characterize the larval abundance and vertical distribution, samplings were carried out in August 2001 at neap tide and 3 stations, with 3 hours interval over 24 hours. Samples were taken at three or two depths at each station, with a plankton pump coupled to a 300 µm mesh size net. Petrolisthes armatus zoea I and II showed a mean of 26.3 ± 83.6 and 12 ± 38.8 ind m-3, respectively. During flood tides, the larvae were more concentrated in the midwater and surface, which avoided the transport to internal regions. In contrast, during ebb tides when the larvae were distributed in the three layers, the higher concentrations were found in the bottom, which avoided a major exportation. The diel dynamic of the larval fluxes was characterized by vertical migration behavior associated to the tidal regime, which suggested that the development of this decapod apparently occurs in the inner shelf (instead of the outer shelf) off this peculiar ecosystem.

Occurrence of the Indo-Pacific freshwater prawn Macrobrachium equidens Dana 1852 on the coast of Brazilian Amazonia, with notes on its reproductive biology

June 2011

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1,620 Reads

The freshwater prawn Macrobrachium equidens, which is native species of the Indo-Pacific Region, was recorded for the first time on the Amazon coast of Brazil. This species was found to inhabit the same environment as two native Macrobrachium species, M. amazonicum and M. acanthurus, and is morphologically very similar to the latter. The identification of the species was confirmed by the genetic analysis of sequences of the mitochondrial Cytochrome Oxidase (COI) gene. A detailed description of the morphological features and reproductive biology of M. equidens in this new environment is presented.

Figure 1 -Azaridachtin molecule.  
Figure 1-Azaridachtin molecule.
Toxicity of Neem's oil, a Potential Biocide against the Invasive Mussel Limnoperna fortunei (Dunker 1857)

September 2012

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179 Reads

The golden mussel Limnoperna fortunei (Dunker 1857) is one of the most distributed Nuisance Invasive Species (NIS) in South America, and a threat of great concern for the industry of the area. In this study, we carried out toxicity tests made with a Neem's oil solution with L. fortunei larvae and benthonic adults (7, 13 and 19 ± 1 mm). Tests with non-target species (Daphnia magna, Lactuca sativa and Cnesterodon decemmculatus) were also made with the aim to evaluate the potential toxicity of the Neem's solution in the environment. The LC100 of Neem's solution obtained for larvae was 500 µl/L, a value much higher than the one obtained for D. magna and C. decemmaculatus. Thus, we recommend that it should not be used in open waters. However, since the adults were killed in 72 h and the larvae in 24 h, this product can be used in closed systems, in man-made facilities.

[Ultrastructure of spermatogenesis and spermatozoa of Emallagma cheliferum Selys, 1875 (Coenagrionidae: Odonata)]

July 1976

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8 Reads

The spermiogenesis in Enallagma cheliferum follows the usual patterns of differentiation in insects. Thus, the Golgi originates the acrosome; the "nebenkern", the mitochondrial structures that form a long tail with the axonema. The axonema has the configuration 9 + 9 + 2 and around the centriole a centriole adjunt is visible in the immature spermatide. The centriole adjunt differentiates into dense bodies as a "demi-lune" shape in the mature sperm.

Figure 1-Linear regression of CO 2 production at different densities of rearing trays of A. kuehniella (with approximately 10,000 larvae in the 5 th instar) per m 3 , 9.79 m 3 rooms, 25 ± 3°C, photophase: 14h. 
Effect of Carbon dioxide (CO2) on mortality and reproduction of Anagasta kuehniella (Zeller 1879), in mass rearing, aiming at the production of Trichogramma spp

June 2013

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128 Reads

Eggs of Anagasta kuehniella (Zeller 1879) are widely used for mass rearing of Trichogramma spp. and other parasitoids and predators, largely commercialized in many countries. The aim of this study is to evaluate the effect of carbon dioxide (CO2) originated from larval metabolism on the biological parameters of A. kuehniella. For that purpose, we assess the production of carbon dioxide (CO2) per rearing tray of A. kuehniella and the effect of CO2 on the viability of egg-to-adult period and oviposition of A. kuehniella. Results allow to estimate that a rearing tray, containing 10,000 larvae between the 4th and 5th instars, produces an average of 30.67 mL of CO2 per hour. The highest egg production of A. kuehniella was obtained when the larvae were kept in rooms with lower concentration of CO2 (1,200 parts per million - ppm), producing 23% more eggs than in rooms with higher CO2 concentrations. In rooms with high density of trays (70 trays/room), CO2 concentration exceeded 4,400 ppm. The viability of the egg-to-adult period was not influenced by carbon dioxide.

Fig. 1 – Erythroblast number (μ ± SD) of juvenile pacu P. mesopotamicus fed increasing levels of dietary vitamin E. Different letters above columns indicate differences by Tukey test (α=0.05).  
Growth and hematology of juvenile pacu Piaractus mesopotamicus (Holmberg 1887) fed with increasing levels of vitamin E (DL-α-tocopheryl acetate)

March 2013

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88 Reads

Intensive fish production systems are characterized by 100% artificial feeding, so any dietary imbalances or deficiencies may lead to diseases outbreaks and economic losses. This study was set out to determine the effects of increasing levels of dietary vitamin E on growth and hematology of juvenile pacu. Fishes were fed for 90 days, twice a day until apparent satiation with semi-purified diets containing 0.0; 25; 50; 150; 300 or 600 mg.kg-1 diet DL-α-tocopheryl acetate in a completely randomized design trial (n=4); biometrical and hematological data were collected and analyzed. Fishes fed with vit E diet (150 mg.kg-1) showed higher (p<0.05) weight gain and specific growth. Hematocrit, erythroblast number and total plasma protein were increased (p<0.05) in fishes fed diet with no vit E diet. Vitamin E supplementation in artificial diets for pacu is essential for growth and maintenance of normal erythropoiesis.

Fig. 1 – Map of Curuçá County (Amazon Region) showing the sampling stations in the Muriá Creek (M1 to M4) and Curuçá River (C1 to C4). metric methodology adapted from Strickland and Parsons (1972). After collection, samples were conditioned in 500 mL plastic flasks containing buffered formalin solution (sodium tetraborate) at 4%. Density was determined calculating the number of sample individuals divided by the filtered seawater volume. Collected organisms were sorted and identified using a Zeiss stereoscopic microscope (Stemi 2000), a light Zeiss microscope (Axioskop 40) and specialized literature (Rose 1933, Trégouboff and Rose 1957). Males and females were identified, dissected and illustrated through schematic drawings for a better species identification. Total body length measurements (abdomen and cephalothorax) were taken using a micrometric scaled rule adjusted to the ocular of the microscope. The entire collection has been deposited in the Laboratory of Plankton and Microalgae Culture/Federal University of Pará-UFPA (North Brazil). Five adult females (Lot 806- F) and six adult males (Lot 805-M) were deposited in the Museu Paraense Emílio Goeldi, Belém – Pará – Northern Brazil.  
Fig. 2 – Cymbasoma longispinosum Bourne, 1890, f#. (A) Female lateral view; (B) Lateral view of the head; (C) Dorsal view of the head; (D) Leg 1; (E) Leg 2; (F) Leg 3; (G) Leg 4; (H) Ventral view of the urosome; (I) Lateral view of the urosome. Scale bar: A = 0.6 mm; B, C and I = 0.3 mm; D, E, F, G and H = 0.15 mm. On the samples collected in September/2003, 156 individuals (89 males and 67 females) were observed. The Muriá sample stations showed a higher number of individuals (145) than those obtained at stations located in the Curuçá River (11). At station M1, 22 individuals comprised of 10 females and 12 males (0.77 org.m −3 ) were observed. Male measured body lengths (cephalotorax and abdomen) ranged from 1.23 mm to 1.50 mm (1.34 ± 0.03 mm, mean ± SD), while female body lengths ranged from 1.83 mm to 2.48 mm, with mean values of 2.09 ± 0.06 mm. At station M2 123 individuals were found, with a  
Fig. 3 – Cymbasoma longispinosum Bourne, 1890, m#. (A) Male lateral view; (B) Lateral view of the head; (C) Dorsal view of the head; (D) Leg 1; (E) Leg 2; (F) Leg 4; (G) Ventral view of the urosome . Scale bar: A = 0.6 mm; B and C = 0.3 mm; D, E, F and G = 0.15 mm. mean density of 4.43 org.m −3 , being 48 females and 75 males. Females presented minimum and maximum body lengths of 1.68 mm and 2.65, respectively, with mean values of 2.10 ± 0.03 mm. Males body lengths ranged from 0.88 mm to 1.63 mm (1.31 ± 0.02 mm). Samples collected at stations M3 and M4 did not present any individuals of the Cymbasoma genera. Of the sampling stations located in the Curuçá River (C1, C2, C3 and C4), only station C4 presented individuals of C. longispinosum. Eleven individuals were registered (7 males and 4 females), with a total density of 0.43 org.m −3 . Male body lengths ranged from 1.00 mm to 1.53 mm (1.24 pm 0.11 mm), while female body lengths ranged from 1.80 mm to 2.48 mm, with mean values of 2.14 ± 0.10 mm. In November, C. longispinosum occurred only at  
Fig. 4 – Average male and female body length variations (mean ± SD) in the different months and sampling stations in the Curuçá River estuary (Curuçá County, Amazon Region). station M1 (Muriá), with a total density of 0.29 org.m −3 . Samples from this month were comprised of 8 individuals , being 5 females and 3 males. Male body lengths ranged from 1.13 mm to 1.50 mm (1.21 ± 0.11 mm), and females from 1.88 mm to 2.78 mm (2.40 ± 0.16 mm). Figure 4 shows the average body length variations for the different months and stations.  
Occurrence of Cymbasoma longispinosum Bourne, 1890 (Copepoda: Monstrilloida) in the Curuca River estuary (Amazon Littoral)

September 2010

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84 Reads

The present work was carried out to verify the occurrence and distribution of Cymbasoma longispinosum Bourne, 1890 in a tropical Amazon estuary from North Brazil. Samplings were performed bimonthly from July/2003 to July/2004 at two different transects (Muriá and Curuçá rivers) situated along the Curuçá estuary (Pará, North Brazil). Samples were collected during neap tides via gentle (1 to 1.5 knots) 200 μm-mesh net tows from a small boat. Additional subsurface water samples were collected for the determination of environmental parameters. Males and females of Cymbasoma longispinosum were only observed during September and November/2003. The highest number of organisms was found in September/2003 at the Muriá River transect. The presence of C. longispinosum in samples obtained during September and November/2003 could probably be related to the reproductive period of this species in the studied estuary, which is directly related to the dry period in the region. The highest salinity values and the highest number of individuals observed in September/2003 corroborate with the previous assumption, since no C. longispinosum was found during the months comprising the rainy period (January to June).

Fig. 38-Map showing the known distribution of Ananteris species in the states of Bahia and Minas Gerais, Brazil. Ananteris evellynae (black circle). Ananteris chagasi (black cross). Ananteris kuryi (black asterisk). Ananteris desiderio sp. n. (black circle). Ananteris camacan sp. n. (black triangle). Ananteris infuscata sp. n. (black star).
Figs. 1-4-Ananteris desiderio sp. n., male holotype. 1-2. Habitus, dorsal and ventral aspects. 3. Carapace and chelicerae in detail, showing pigmentation pattern. 4. Ventral aspect showing sternum, genital operculum and pectines.
Description of three more new species of the genus Ananteris Thorell, 1891 (Scorpiones, Buthidae) from Brazil

June 2013

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166 Reads

Three new species of the genus Ananteris Thorell have been discovered in Brazil. Ananteris desiderio sp. n., Ananteris camacan sp. n. and Ananteris infuscata sp. n. are respectively described from specimens collected in the regions of São Desidério, Camacã, Rebio UNA and Jequié in the state of Bahia, and Grão Mogol and Novo Horizonte in the state of Minas Gerais, Brazil. New records are also proposed for Ananteris luciae Lourenço, Ananteris mauryi Lourenço and Ananteris franckei Lourenço. The number of known Ananteris species known in the scorpion fauna of Brazil is now raised to 24.

Fig. 1 – Egg production in the copepod Acartia tonsa using three different food sources: the microalgae Thalassiosira weissflogii (closed circles; solid line; top x axis), Chaetoceros muelleri (closed squares; short dashed line; bottom x axis) and Isochrysis galbana (open circles; long dashed line; bottom x axis). Different cell densities were tested for each microalgae species to give an equivalent biovolume value at each experimental condition. Copepods were acclimated to fixed salinity (30), temperature (20 @BULLET C) and photoperiod (12L:12D) before tests. Tests were performed under the same acclimation conditions. Results are expressed as mean ± standard error. Data were analyzed by non-linear regression analysis (exponential with saturation). Pm = maximum egg production expressed as eggs.female −1 .day −1 . R 2 = regression coefficient. Egg production data with I. galbana at 160.10 3 cells.mL −1 (open triangle) was considered as an outlier.  
Diet influence on egg production of the copepod Acartia tonsa (Dana, 1896)

June 2010

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241 Reads

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 degrees 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 60.10(3) 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 10.10(3), 140.10(3) and 640.10(3) 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.

Mutations in collagen 18A1 (COL18A1) and their relevance to the human phenotype

April 2006

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67 Reads

Collagen XVIII, a proteoglycan, is a component of basement membranes (BMs). There are three distinct isoforms that differ only by their N-terminal, but with a specific pattern of tissue and developmental expression. Cleavage of its C-terminal produces endostatin, an inhibitor of angiogenesis. In its N-terminal, there is a frizzled motif which seems to be involved in Wnt signaling. Mutations in this gene cause Knobloch syndrome KS), an autosomal recessive disorder characterized by vitreoretinal and macular degeneration and occipital encephalocele. This review discusses the effect of both rare and polymorphic alleles in the human phenotype, showing that deficiency of one of the collagen XVIII isoforms is sufficient to cause KS and that null alleles causing deficiency of all collagen XVIII isoforms are associated with a more severe ocular defect. This review besides illustrating the functional importance of collagen XVIII in eye development and its structure maintenance throughout life, it also shows its role in other tissues and organs, such as nervous system and kidney.

Spectral changes of nucleic acids and nucleotide solutions at the 190-220nm region

July 1976

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4 Reads

Nucleic acids and nucleotide solutions have between 190 and 220 nm an hypo-bathochromic effect electrostatistically induced by acylic groups or by effective binding of several substances. In the former case, with DNA or RNA, the effect reverts through gel filtration and dialysis. In the latter case no reversion occurs. This is proposed as a probe for complex formation with the nucleic acid bases. Thermal denaturation of DNA solutions gives to the above mentioned maximum, an hyperchromicity somewhat different from the usually obtained at 260 nm.

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