As variaveis relevo e 'solo' na distribuicao desigual da umidade do solo. Avaliacao preliminar.

In a general way the analysis of soil water content enabled one to define which of the colluvium units hold larger water retention capacity. They are: Bela Vista, Piracema I, Campo Alegre, Bom Retiro and Treviso II. These results suggest that the contact zones among alostratigraphic units with high and low water retention capacity are potential zones for the generation of subsurface flow (throughflow). -from English summary

A SequenceSpace analysis of Lys49 phospholipases A2: Clues towards identification of residues involved in a novel mechanism of membrane damage and in myotoxicity

'SequenceSpace' analysis is a novel approach which has been used to identify unique amino acids within a subfamily of phospholipases A2 (PLA2) in which the highly conserved active site residue Asp49 is substituted by Lys (Lys49-PLA2s). Although Lys49-PLA2s do not bind the catalytic co-factor Ca2+ and possess extremely low catalytic activity, they demonstrate a Ca2+-independent membrane damaging activity through a poorly understood mechanism, which does not involve lipid hydrolysis. Additionally, Lys49-PLA2s possess combined myotoxic, oedema forming and cardiotoxic pharmacological activities, however the structural basis of these varied functions is largely unknown. Using the 'SequenceSpace' analysis we have identified nine residues highly unique to the Lys49-PLA2 sub-family, which are grouped in three amino acid clusters in the active site, hydrophobic substrate binding channel and homodimer interface regions. These three highly specific residue clusters may have relevance for the Ca2+-independent membrane damaging activity. Of a further 15 less stringently conserved residues, nine are located in two additional clusters which are well isolated from the active site region. The less strictly conserved clusters have been used in predictive sequence searches to correlate amino acid patterns in other venom PLA2s with their pharmacological activities, and motifs for presynaptic and combined toxicities are proposed.

Estimativa do tamanho das fêmeas com ovos de Moina minuta Hansen, 1899 (Cladocera, Crustacea) no lago Amapá, Rio Branco, Estado do Acre Brasil

Moina minuta, a tropical species of Cladocera, was selected for the study of medium size at maturity and female egg production, due to its abundance and frequency in samples during low-water season in 1997 and high-water season in 1998, in Amapá Lake, Western Amazônia. The primiparous female had a size of 330 μm and 340 μm in low and high water, respectively. Moina individuals reached maximum size during high water (595μm). The medium size of the ovigerous females, in low water was 501 μm, producing an average of 4.41 eggs/female, while in high water, it was 533μm, with an average egg production of 4.84 eggs/female. The results, analyzed by the t test and Fischer's F test, showed that there were no statistical differences in size among individuals (t= -10.69, F=1.20 and P>0.1227), nor among ovigerous females (t= -4.45, F=1.02 and P>0.8906), considering the two seasons.

Influência do alecrim (Rosmarinus officinallis L.) na atividade de água e oxidação lipídica de peixes de uma espécie de tilápia (Oreochromis ssp-var. vermelha Flórida) submetidos à salga

Salting have been a very utilized fish conservation method, however only in the last years the basic mechanism involved in salting fish has been understood. The objectives of this study were determine the addition in brine salt of rosemary leaves, rosemary extracts and tocopherol, and your action in the followed parameters: water activity (Aw), moisture, ash, salt content and TBARS. The results showed that the addition of antioxidants was difficulted the salt absorption, however didn't have differences between rosemary or tocopherol use. In the salting time of 3 hours the values of Aw and salt levels, was respectively: 0.77±0.01 and 14.42±1.69. for control treatment; 0.85±0.02 and 9.09±1.39for rosemary filtrate; 0.78±0.03 and 10.63±0.69 rosemary without filtrating and 0.85±0.02 and 11.96±1.78 tocopherol, showed that didn't grow indigenous bacterias. Lipid oxidation was evaluated by TBARS and the results showed the oxidative effect of salt and the pro oxidant effects of alls antioxidants used in brine salting.

Agronomic effectiveness of cationic phosphate impurities present in superphosphate fertilizers as affected by soil pH

The general concept that low-water-soluble phosphorus (P) fertilizers should be more agronomically effective when applied to acidic soils was developed based on sources containing mainly calcium (Ca)-P compounds, but it may not hold true for sources with different chemical composition. To obtain information related to this issue, two important iron (Fe)-potassium (K)-P compounds present in superphosphates [Fe 3 KH 8 (PO 4 ) 6·6H 2 O, H8, and Fe 3 KH 14 (PO 4 ) 8·4H 2 O, H14] were prepared and characterized. These P sources were used to provide 30 and 60 mg P kg -1 as neutral ammonium citrate (NAC)+H 2 O-soluble P. Reagent-grade monocalcium phosphate (MCP) was used as a standard P source with high water solubility with an additional rate of 120 mg P kg -1 included. Also, mixtures of both Fe-K-P compounds and MCP were prepared to provide 0, 25, 50, 75, and 100% of the total P as MCP. All sources were applied to a clayey loamy acid soil (pH 5.3) classified as Rhodic Kanhapludult. The soil was incubated at two rates (0 and 10 g kg -1 ) of lime, which resulted in pH 5.4 and 6.8. Upland rice was cultivated to maturity. The H14 compound confirmed to be a highly effective source of P for the rice plants at both soil pH, as opposed to the H8, which was poorly effective when applied alone. When mixed with water-soluble P (WSP), the H8 was able to provide P to the plants with the maximum yield of upland rice reached with 54.8 and 80.5% of WSP for pH 5.4 and 6.8, respectively. The high agronomic performance of the H14 compound clearly indicates that this low-water-soluble P source cannot be deemed as ineffective at high soil pH. Copyright © Taylor & Francis Group, LLC.

Influência da granulometria de grânulos de amido sobre a densidade aparente de extratos atomizados

Starches and modified starch derivations are used as carriers in the spray drying processing where apparent density is an important characteristic and should be controlled in dehydrated products for pharmaceutical use. In Brazil, the commercial starches are made from corn and cassava, but there are others with potential for extraction. The canna and taro starches were selected because they represent the extremes of granule size and thus allow the effect of this size on the apparent density of spray dried products to be tested. For comparison, commercial cassava and corn starches which are used in spray-drying and have granules of intermediate size, were also tested. The spray-drying process was carried out with a LabPlant SD 04 Spray Dryer, operating at a pressure of 6 lb/in2, air of 7,6 mL/minute, and 1 cm atomizing nozzle. The air inlet temperature was set at 200°C this model does not allow regulating outlet temperature. The spray-dryer products had boldo leaf extract as base, using the four starches as carrier. The dry product was evaluated for humidity, water activity (Aw), granulometry and apparent density. The results showed that the size of the particles, which was a consequence of the size of the starch granules, influenced the apparent density of the spray dried products, which as higher (694, 27 g/mL) for the canna starch and lower (456, 13 g/mL) for taro starch. Corn and cassava starches showed very close and intermediate values, 521,51 and 58,48 g/mL, which also represent the standard range of starch granule size.

Uso de regressão linear para estimar parâmetros físico-químicos relacionados à qualidade do jerked beef

Jerked beef is officially defined as salted, cured and dried beef. Water activity (Aw), moisture, ash and residual nitrite are the physicochemical parameters that define this product identity and quality standards. In this work, the behavior of these parameters during jerked beef processing was evaluated and a significant correlation among them was revealed. These results allowed the establishment of statistical equations that enable the estimation of all the physicochemical parameters from the results obtained in the measurement of just one of them.

Electromyographic analysis of the rectus abdominis muscle in pelvic retroversion and the decrease of the lower limbs

We often face Patients searching for rehabilitation for lower back disorders during the physiotherapeutic routine, and it is known that the abdominal muscle, specially the rectus abdominis muscle, aid the stabilization of the pelvis. Therefore, this paper analyzes the electrical activity of the rectus abdominis muscle in the pelvic retroversion in dorsal decubitus and in orthostatic position and in the lowering of the lower limbs. 30 healthy students, male and female, 17-40 yr, divided into two groups - Group 1: 15 volunteers (pelvic balance); Group 2 (pelvic unbalance) took part in this study. The electrical activity of the right and left supra-umbilical and infra-umbilical portions of the rectus abdominis muscle was detected. The mean RMS values from three attempts ftom the electromyographic traces were usedfor the analysis of the electrical activity. The RMS value was submitted to the normalization process. The data were submitted to statistic treatment by the Friedman test, and the analyses of the means and standard deviation towards a level of significance of 95%. The results demonstrated that the portions of the rectus abdominis muscle presented low electrical activity for the groups studiedfor pelvic retroversion either in dorsal decubitus or and orthostatic position. However, the decreasing movement of the lower limbs towards the portions of the rectus abdominis muscle presented more significant electrical activity whereas the lower portions presented higher activity than the higher ones for Group 2.

Atividade antioxidante e antimicrobiana do alecrim (Rosmarinus officinalis L.) em filés de tilápia (Oreochromis ssp) salgados secos durante o armazenamento congelado

Rosemary (Rosmarinus officinalis L.) is a spice from Lamiaceae family known since ancient times because its medicinal effects and, currently, several studies have pointed its antioxidant and antimicrobian effects. Lipid oxidation is a problem in food production because proceed the lost of organoleptical and nutritional qualities so required in Market. Fish salting is an ancient conservation method that expect reduce water activity and, consequently, microorganism growth in food, except halophillic bacteria. In the meantime, the inconvenient of this procedure is that the salt accelerates tissue's lipid oxidation. The aim of this work was evaluate the antioxidative and antimicrobian effects by treatment and pre treatment with rosemary (Rosmarinus officinalis L.) aqueous extract in dry salted tilapia fillets, storaged in freezing temperatures. To follow the oxidative, dry salted tilapia fillets were treated or pre treated with rosemary natural extract and storage at -18°C for 240 days. Analisys of 2-thiobarbituric acid reactive substances (TBARS), soluble nitrogen in trichloroacetic acid (TCA), water activity and microbiology were done. The pre treatment (3.39±0,53) and the treatment with rosemary (3.31±0.79) had oxidative index twice lower than the control treatment (6.14±1.21) in the last time of the research. The microbiological rosemary analisys showed count levels of resistant microorganisms to salt (2.0×103CFU/g of sample), whom causes the initial fillets contamination. The microbiological counts remained invariable in all groups during storage periods.

O papel das argininas alfa-92 e alfa-141 na regulação das propriedades funcionais de hemoglobinas por íons cloreto

The oxygenation of human Hb (HbA) demands a three state model: two deoxy states To and Tx, free and complexed with anions respectively, and an oxy R state. The regulation between these states is modulated by the presence of anions, such as chloride, that binds to T state. The b inding if chloride, however, remains controversial. The aim of this work is the study of arginines 92a (a1ß2 interface) and 141a (C-terminal) as chloride binding sites. To investigate that, we have studied 92 and 141 site directed mutant species: natural mutants Hb J-Cape-Town (R92Q), desArg (R141Δ), Chesapeake (R92L), and the constructed Chesapeake desArg (R92L,141Δ). We expressed Hbs in Escherichia coli and purified. Through oxygen binding curves we measured affinity and cooperativity, in function of water effect and Bohr effect in presence and absence of chloride. Structural features were obtained through 1H NMR spectroscopy Oxygen binding properties and Bohr effect measured indicated a higher affinity and lower cooperativity in absence and presence of chloride for all mutants. Structural changes represent functional aspects of mutant Hbs, such as a significant rise in affinity or a change in cooperativity. Water activity studies conducted as a function of chloride concentration showed that the only Hb desArg follows the thre state model. The other mutant Hbs do not exhibit the Tx state, a fact confirmed by the number of water molecules bound to each Hb during the deoxy-oxy transition. This behavior suggests that the Arginine 92 site could be responsible for chloride binding to Hb, since oxygenation of 92 mutant Hbs cannot be adjusted by the three state model. However, Bohr effect showed that all mutant Hbs released~1 proton in chloride presence, different from HbA that releases ~2, suggesting a role for 141 arginine in the tertiary and quaternary Bohr effect.

Efecto del método de secado en las propiedades termodinámicas de pulpa de mora en polvo

Three different types of maltodextrin encapsulated dehydrated blackberry fruit powders were obtained using vibrofluidized bed drying (VF), spray drying (SD), vacuum drying (VD), and freeze drying (FD). Moisture equilibrium data of blackberry pulp powders with 18% maltodextrin were determined at 20, 30, 40, and 50°C using the static gravimetric method for the water activity range of 0.06-0.90. Experimental equilibrium moisture content data versus water activity were fit to the Guggenheim-Anderson-de Boer (GAB) model. Agreement was found between experimental and calculated values. The isosteric heat of sorption of water was determined using the Clausius-Clapeyron equation from the equilibrium data; isosteric heats of sorption were found to increase with increasing temperature and could be adjusted by an exponential relationship. For freeze dried, vibrofluidized, and vacuum dried pulp powder samples, the isosteric heats of sorption were lower (more negative) than those calculated for spray dried samples. The enthalpy-entropy compensation theory was applied to sorption isotherms and plots of ΔH versus ΔS provided the isokinetic temperatures, indicating an enthalpy-controlled sorption process.

Modelling thermodynamic properties of banana waste by analytical derivation of desorption isotherms

Banana is an agricultural product of great economic importance for various developing countries. The relationship between moisture content and water activity provides useful information for the processing and storage of banana waste. The water activity and moisture content of three banana (Mussa spp. Haploid AAB cv. Nanica) waste items were analyzed to determine the desorption isotherms at six different temperatures (20, 30, 40, 50, 60 and 70°C). The desorption isotherms of the peel, pedicel and pulp of overripe bananas were determined in wide ranges of moisture content (0.001-6.360 kg kg-1 d.b.) and water activity (0.02-0.907). The theoretical GAB model was used for modelling the desorption isotherms. An analytical solution of the Clausius-Clapeyron equation was proposed to compute the isosteric heat of sorption, the differential entropy and Gibbs' free energy by way of the GAB model when the effect of temperature on the hygroscopic equilibrium was considered. © 2012 de Gruyter. All rights reserved.

Preparation and characterization of the bacterial cellulose/polyurethane nanocomposites

New nanocomposites based on bacterial cellulose nanofibers (BCN) and polyurethane (PU) prepolymer were prepared and characterized by SEM, FT-IR, XRD, and TG/DTG analyses. An improvement of the interface reaction between the BCN and the PU prepolymer was obtained by a solvent exchange process. FT-IR results showed the main urethane band at 2,270 cm-1 to PU prepolymer; however, in nanocomposites new bands appear as disubstituted urea at 1,650 and 1,550 cm-1. In addition, the observed decrease in the intensity of the hydroxyl band (3,500 cm-1) suggests an interaction between BCN hydroxyls and NCO-free groups. The nanocomposites presented a non-crystalline character, significant thermal stability (up to 230 °C) and low water absorption when compared to pristine BCN. © 2013 Akadémiai Kiadó, Budapest, Hungary.

Qualidade física de ovos armazenados em diferentes condições de embalagens sob temperatura ambiente

The objective was to evaluate the internal quality of white-shelled consume eggs, sanitized or not, stored under different packaging conditions at room temperature. It was used 300 eggs, distributed in a completely randomized experimental design in a 3×2×4+1 factorial arrangement, three packaging conditions (PVC film, partial vacuum, partial vacuum with oxygen gas absorber), storage period (7, 14, 21 and 28 days), sanitized or not, and control (fresh eggs), with four repetitions. At the end of each period the analysis were performed. Partial vacuum condition was able to maintained Haugh unit, and promoted the best results for yolk index. The weight maintenance was better when packaged under vacuum, with or without O2 sachets absorbers. Lower values of water activity were obtained in eggs packed in PVC film, and when the sanitation was performed. It can be concluded that the internal egg quality decreases with storage time sharper in the eggs packed in PVC film, because vacuum has preserved some features of them. With sanitation, the storage conditions of eggs in PVC film should be improved because its internal quality decrease was greatest.

Enzymatic transesterification of soybean oil with ethanol using lipases immobilized on highly crystalline PVA microspheres

Polyvinyl alcohol (PVA) microspheres with different degree of crystallinity were used as solid supports for Rhizomucor miehei lipase immobilization, and the enzyme-PVA complexes were used as biocatalysts for the transesterification of soybean oil to fatty acid ethyl esters (FAEE). The amounts of immobilized enzyme on the polymeric supports were similar for both the amorphous microspheres (PVA4) and the high crystalline microspheres (PVA25). However, the enzymatic activity of the immobilized enzymes was depended on the crystallinity degree of the PVA microspheres: enzymes immobilized on the PVA4 microspheres have shown low enzymatic activity (6.13 U mg-1), in comparison with enzymes immobilized on the high crystalline PVA25 microspheres (149.15 U mg-1). A synergistic effect was observed for the enzyme-PVA25 complex during the transesterification reaction of soybean oil to FAEE: transesterification reactions with free enzyme with the equivalent amount of enzyme that were immobilized onto the PVA25 microspheres (5.4 U) have yielded only 20% of FAEE, reactions with the pure highly crystalline microsphere PVA25 have not yielded FAEE, however reactions with the enzyme-PVA25 complexes have yielded 66.3% of FAEE. This synergistic effect of an immobilized enzyme on a polymeric support has not been observed before for transesterification reaction of triacylglycerides into FAEE. Based on ATR-FTIR, 23Na- and 13C-NMR-MAS spectroscopic data and the interaction of the polymeric network intermolecular hydrogen bonds with the lipases residual amino acids a possible explanation for this synergistic effect is provided. © 2013 Elsevier Ltd. All rights reserved.