Evaluation of FAO Penman-Monteith and alternative methods for estimating reference evapotranspiration with missing data in Southern Ontario, Canada

Grass reference evapotranspiration (ETo) is an important agrometeorological parameter for climatological and hydrological studies, as well as for irrigation planning and management. There are several methods to estimate ETo, but their performance in different environments is diverse, since all of them have some empirical background. The FAO Penman-Monteith (FAD PM) method has been considered as a universal standard to estimate ETo for more than a decade. This method considers many parameters related to the evapotranspiration process: net radiation (Rn), air temperature (7), vapor pressure deficit (Delta e), and wind speed (U); and has presented very good results when compared to data from lysimeters Populated with short grass or alfalfa. In some conditions, the use of the FAO PM method is restricted by the lack of input variables. In these cases, when data are missing, the option is to calculate ETo by the FAD PM method using estimated input variables, as recommended by FAD Irrigation and Drainage Paper 56. Based on that, the objective of this study was to evaluate the performance of the FAO PM method to estimate ETo when Rn, Delta e, and U data are missing, in Southern Ontario, Canada. Other alternative methods were also tested for the region: Priestley-Taylor, Hargreaves, and Thornthwaite. Data from 12 locations across Southern Ontario, Canada, were used to compare ETo estimated by the FAD PM method with a complete data set and with missing data. The alternative ETo equations were also tested and calibrated for each location. When relative humidity (RH) and U data were missing, the FAD PM method was still a very good option for estimating ETo for Southern Ontario, with RMSE smaller than 0.53 mm day(-1). For these cases, U data were replaced by the normal values for the region and Delta e was estimated from temperature data. The Priestley-Taylor method was also a good option for estimating ETo when U and Delta e data were missing, mainly when calibrated locally (RMSE = 0.40 mm day(-1)). When Rn was missing, the FAD PM method was not good enough for estimating ETo, with RMSE increasing to 0.79 mm day(-1). When only T data were available, adjusted Hargreaves and modified Thornthwaite methods were better options to estimate ETo than the FAO) PM method, since RMSEs from these methods, respectively 0.79 and 0.83 mm day(-1), were significantly smaller than that obtained by FAO PM (RMSE = 1.12 mm day(-1). (C) 2009 Elsevier B.V. All rights reserved.

Evaluation of GFP Tag as a Screening Reporter in Directed Evolution of a Hyperthermophilic beta-Glucosidase

By applying a directed evolution methodology specific enzymatic characteristics can be enhanced, but to select mutants of interest from a large mutant bank, this approach requires high throughput screening and facile selection. To facilitate such primary screening of enhanced clones, an expression system was tested that uses a green fluorescent protein (GFP) tag from Aequorea victoria linked to the enzyme of interest. As GFP`s fluorescence is readily measured, and as there is a 1:1 molar correlation between the target protein and GFP, the concept proposed was to determine whether GFP could facilitate primary screening of error-prone PCR (EPP) clones. For this purpose a thermostable beta-glucosidase (BglA) from Fervidobacterium sp. was used as a model enzyme. A vector expressing the chimeric protein BglA-GFP-6XHis was constructed and the fusion protein purified and characterized. When compared to the native proteins, the components of the fusion displayed modified characteristics, such as enhanced GFP thermostability and a higher BglA optimum temperature. Clones carrying mutant BglA proteins obtained by EPP, were screened based on the BglA/GFP activity ratio. Purified tagged enzymes from selected clones resulted in modified substrate specificity.

Sensory evaluation of precooked chicken meat with mate (Ilex paraguariensis) added as antioxidant

Dried mate leaves or aqueous extract of dried mate leaves added to chicken meat balls prior to cooking for antioxidant protection was found not to affect taste or smell of the product significantly for addition corresponding to 0.050% of dried mate leaves, while 0.10% changed the smell but not the taste and more significantly for dried leaves. Addition of aqueous mate extract corresponding to 0.050% of mate is recommended as an alternative to more strongly flavoured herbs for oxidative protection of meat products.

Correlation between sensory and chemical markers in the evaluation of Brazil nut oxidative shelf-life

Sensory analysis is one of the most suitable processes for measuring oxidative damage and determining the shelf-life of nuts, but it is an expensive and time-consuming methodology. Thus, our objective was to correlate sensory data and chemical markers obtained during the accelerated oxidation of Brazil nuts and to determine the chemical parameters values associated with the sensory shelf-life of the nuts as established by the consumers. Brazil nuts were kept at 80 A degrees C for 21 days. At intervals of 2 days, the oxidized odor of the samples was analyzed by nine trained panelists using a discriminative scale, and the oil was extracted to quantify the chemical parameters. A high (r > 0.95) and significant correlation (p < 0.05) was observed between the sensory data and the hydroperoxide concentration (PV), para-anisidine value (pAV), hexanal content, and alpha- and gamma-tocopherol concentrations. When compared with fresh samples, sensory identification of oxidized odor occurred on the 4th day, noticeably earlier than changes in chemical markers (12th day). Consumers rejected the nuts after 12 days of storage, which corresponded to PV = 18.8 meq kg(-1) oil, pAV = 7.68, hexanal = 48.95 mu mol 100 g(-1) oil, alpha-tocopherol = 15.01 mg kg(-1) oil, and gamma + beta-tocopherol = 73.88 mg kg(-1) oil. Our study suggests that simple spectrometric methods, such as PV and pAV, can be used to estimate the oxidative shelf-life of nuts based on sensory analysis.

In Vitro Sun Protection Factor Evaluation of Sunscreens Containing Rutin and its Derivative

This research aimed at determining spectrophotometrically (290 to 320nm) the in vitro Sun Protection Factor (SPF) of sunscreens developed with rutin (R) or succinate rutin (SR), in association or not with UVB filter. Formulations were developed based on phosphate-base O/W emulsions, with (B) or not (A) the presence of polyacrylamide/C13-14 isoparaffin/laureth-7 (PIL), in accordance with the following associations: (a) control; (b) 1.0 % SR; (c) 0.1 % R; (d) 7.5 % ethylhexyl methoxycinnamate (EHMC); (e) 7.5 % EHMC + 0.1 % RS; (0 7.5 % EHMC + 0.1 % R. It was verified a statistical significative elevation of the SPF from 13.93 +/- 0.02 (Af) to 16.63 +/- 0.27 (Bf) and also in relation to 15.53 +/- 0.14 (Bd). According to the results, the EHMC had distinct behavior depending on the presence of bioactive substance and viscosity agent, thus, rutin obtained better profile as a SPF booster in these experimental conditions with the presence of PIL.

Bioequivalence Evaluation of Two Different Tablet Formulations of Tinidazole in Healthy Volunteers

The bioequivalence of two different tablet formulations of tirtidazole (CAS 19387-91-8) was determined in healthy volunteers after a single dose in a randomized crossover study, with a 1-week washout period between the doses. Reference and test products were administered to 24 volunteers with 240 mL water after overnight fasting. Plasma concentrations of tinidazole were monitored by a high-performance liquid chromatographic method (HPLC) over a period of 72 h after the administration. The pharmacokinetic parameters AUC(0-t), AUC(0-infinity), C(max), T(max), T((1/2)el) and beta were determined from plasma concentration time profile of both formulations and found to be in good agreement with previously reported values. The calculated pharmacokinetic parameters were compared statistically to evaluate bioequivalence between the two brands. The analysis of variance (ANOVA) did not show any significant difference between the two formulations and 90% confidence intervals for the ratio of C(max) (93.9 - 102.6%), AUC(0-t), (94.9-101.1%) and AUC(0-infinity) (94.6-100.8%) values for the test and reference products were within the 80 - 125% interval, satisfying bioequivalence criteria of the European Committee for Proprietary Medicinal Products and the US Food and Drug Administration Guidelines. These results indicate that the test and the reference products of tinidazole are bioequivalent and, thus, may be prescribed interchangeably.

Rutin association with ethylhexyl methoxycinnamate and benzophenone-3: In vitro evaluation of the photoprotection effectiveness by reflectance spectrophotometry

There is a world tendency to the development of sunscreens possessing reduced concentration of UV filters and, yet, with high UVA-UVB protection. This research work proposes the development and in vitro efficacy evaluation of sunscreens containing rutin, an antioxidant flavonol, associated or not to UVA (benzophenone-3) and UVB (ethylhexyl methoxycinnamate) filters. Formulations were in vitro assayed by reflectance spectrophotometry with integrated sphere, regarding the following parameters: estimated sun protection factor (SPF), critical wavelength (nm) and UVA/UVB ratio. Rutin 0.1% w/w photoprotection efficacy presented dependent of the concentration and presence of the UVA and UVB filters, and it was verified synergism on the SPF elevation, from 7.34 +/- 0.24 to 9.97 +/- 0.18, when the flavonoid was associated with the filters in minimum concentrations. Isolated rutin exerted UVA protection superior to the formulation not added to UV filters and their associations.

Effect of freeze-drying on the mechanical, physical and morphological properties of glutaraldehyde-treated bovine pericardium: evaluation of freeze-dried treated bovine pericardium properties

Purpose: Biomaterials have been widely used in the field of regenerative medicine. Bovine pericardium tissue has been successfully used as a bioprosthetic material in manufacturing heart valves, but studies concerning the tissue are ongoing in order to improve its storage, preservation and transportation. This article provides an overview of the characteristics of bovine pericardium tissue chemically treated after the freeze-drying process. These characteristics are essential to evaluate the changes or damage to the tissue during the process. Methods: The mechanical properties of the tissue were analyzed by three different methods due to its anisotropic characteristics. The physical properties were analyzed by a colorimetric method, while the morphological properties were evaluated by scanning electron microscopy (SEM). Results: The freeze-dried bovine pericardium showed no significant change in its mechanical properties. There was no significant change in the elasticity of the tissue (p > 0.05) and no color change. In addition, SEM analysis showed that the freeze-dried samples did not suffer structural collapse. Conclusions: It was concluded that glutaraldehyde-treated bovine pericardium tissue showed no significant change in its properties after the freeze-drying process.

Evaluation of culture media for enumeration of Lactobacillus acidophilus, Lactobacillus casei and Bifidobacterium animalis in the presence of Lactobacillus delbrueckii subsp bulgaricus and Streptococcus thermophilus

The study compared the growth capability of probiotic (Lactobacillus acidophilus La05, Lactobacillus casei Lc01 and Bifidobacterium animalis Bb12) and non-probiotic (Lactobacillus delbrueckii subsp bulgaricus and Streptococcus thermophilus) cultures on twenty-one culture media grouped according to selectivity: nonselective agars, selective agars without antibiotics and MRS agars containing different combinations of lithium chloride, cystein, bile salts and antibiotics. Four of these media were selected for quantitative enumeration of L acidophilus La05, L casei Lc01, and B. animalis Bb12. The best culture media and incubation conditions for enumeration of the probiotic cultures were: B. animalis: MRS agar with dicloxacillin, 37 degrees C or 42 degrees C, anaerobiosis; L acidophilus: MRS agar with bile salts, 37 degrees C or 42 degrees C, aerobiosis; L casei: MRS agar with lithium chloride and sodium propionate, 37 degrees C or 42 degrees C, aerobiosis or anaerobiosis. Plating on MRS with glucose replaced by maltose, 37 degrees C or 42 degrees C, anaerobiosis, will distinguish probiotic from non-probiotic cultures. For enumeration of each probiotic in a mixed culture, the following media and incubation conditions were recommended: B. animalis: 4ABC-MRS, 42 degrees C, anaerobiosis, L acidophilus: LC medium, 42 degrees C, aerobiosis or anaerobiosis and L casei: LP-MRS, 42 degrees C, aerobiosis or anaerobiosis. In all experiments, differences in counts using pour plating or surface plating were not significant (P <= 0.05). (C) 2008 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.

Trypanosoma cruzi: evaluation of (-)-cubebin derivatives activity in the messenger RNAs processing

No fully effective treatment has been developed since the discovery of Chagas` disease. Since drug-resistant Trypanosoma cruzi strains are occurring and the current therapy is effective in the acute phase but with various adverse side effects, more studies are needed to characterize the susceptibility of T. cruzi to new drugs. Pre-mRNA maturation in trypanosomatids occurs through a process called trans-splicing, which is unusual RNA processing reaction, and it implies the processing of polycistronic transcription units into individual mRNAs; a short transcript spliced leader (SL RNA) is trans-spliced to the acceptor pre-mRNA, giving origin to the mature mRNA. Cubebin derivatives seem to provide treatments with less collateral effects than benznidazole and showed similar or better trypanocidal activities than benznidazole. Therefore, the cubebin derivatives ((-)-6,6`-dinitrohinokinin (DNH) and (-)-hinokinin (HQ)) interference in the mRNA processing was evaluated using T. cruzi permeable cells (Y and BOL (Bolivia) strains) following by RNase protection reaction. These substances seem to intervene in any step of the RNA transcription, promoting alterations in the RNA synthesis, even though the RNA processing mechanism still occurs. Furthermore, HQ presented better activity against the parasites than DNH, meaning that BOL strain seems to be more resistant than Y.

An evaluation, using the comet assay and the micronucleus test, of the antigenotoxic effects of chlorophyll b in mice

We investigated the effects of the dietary pigment chlorophyll b (CLb) on cisplatin (cDDP)-induced oxidative stress and DNA damage, using the comet assay in mouse peripheral blood cells and the micronucleus (MN) test in bone marrow and peripheral blood cells. We also tested for thiobarbituric acid reactive substances (TBARS) and reduced glutathione (GSH) in liver and kidney tissues, as well as catalase (CAT) activity and GSH in total blood. CLb (0.2 and 0.5 mg/kg b.w.) was administrated by gavage every day for 13 days. On the 14th day of the experiment, 6 mg/kg cDDP or saline was delivered intraperitoneally. Treatment with cDDP led to a significant decrease in DNA migration and an increase in MN frequency in both cell types, bone marrow and peripheral blood cells. In the kidneys of mice treated with cDDP, TBARS levels were increased, whereas GSH levels were depleted in kidney and liver. In mice that were pretreated with CLb and then treated with cDDP, TBARS levels maintained normal concentrations and GSH did not differ from cDDP group. The improvement of oxidative stress biomarkers after CLb pre-treatment was associated with a decrease in DNA damage, mainly for the highest dose evaluated. Furthermore, CLb also slightly reduced the frequency of chromosomal breakage and micronucleus formation in mouse bone marrow and peripheral blood cells. These results show that pre-treatment with CLb attenuates cDDP-induced oxidative stress, chromosome instability, and lipid peroxidation. (C) 2011 Elsevier B.V. All rights reserved.

Evaluation of Antigenotoxic Effects of Plant Flavonoids Quercetin and Rutin on HepG2 Cells

The flavonoid quercetin and its derivative rutin were investigated for genotoxicity/antigenotoxicity activity in human hepatoma HepG2 cells using the comet assay. The extract cytotoxicity was evaluated using the trypan blue exclusion dye method with quercetin and rutin concentrations ranging from 0.1 to 200.0 mu g/mL of culture medium. Three minor non-cytotoxic concentrations were chosen to evaluate the genotoxicity and antigenotoxicity of the flavonoids (0.1, 1.0 and 5.0 mu g/mL) through comet assay. The cultures were treated with three different concentrations of rutin or quercetin (genotoxicity) or their association with Aflatoxin B1 (AFB1), methyl methanesulfonate (MMS) or doxorubicin (DXR) (antigenotoxicity test) in three protocols: pretreatment, simultaneous treatment and post-treatment. The cell cultures were also treated with 1% DMSO (control group), AFB1, MMS and DXR (positive-control). Statistical analyses were performed using ANOVA and Dunnett`s test (p <= 0.05). Quercetin at concentrations higher than 10.0 mu g/mL or rutin higher than 50.0 mu g/mL exhibited a cytotoxic effect on the cells, showing that quercetin is more cytotoxic than rutin. Furthermore, neither compound was able to induce genotoxicity in the concentrations evaluated. On the other hand, both flavonoids reduced DNA damage induced by AFB1, MMS and DXR in all treatment protocols. Copyright (C) 2011 John Wiley & Sons, Ltd.

Evaluation of protective effects of fish oil against oxidative damage in rats exposed to methylmercury

The present study evaluates a possible protective effect of fish oil against oxidative damage promoted by methylmercury (MeHg) in sub-chronically exposed rats. Reduced glutathione peroxidase and catalase enzyme activity and reduced glutathione levels were observed in MeHg-exposed animals compared to controls. Methylmercury exposure was also associated with DNA damage. Administration of fish oil to the methylmercury-exposed animals did not ameliorate enzyme activity or glutathione levels. On the other hand, a significant DNA protective effect (about 30%) was observed with fish oil treatment. There were no differences in the total mercury concentration in rat liver, kidney, heart or brain after MeHg administration with or without fish oil co-administration. Histopathological analyses showed a significant leukocyte infiltration in rat tissues after MeHg exposure, but this effect was significantly reduced after co-administration of fish oil. Taken together, our findings demonstrate oxidative damage even after low-level MeHg exposure and the protective effect of fish oil. This protection seems not to be related to antioxidant defenses or mercury re-distribution in rat tissues. It is probably due to the anti-inflammatory effects of fish oil. (C) 2010 Elsevier Inc. All rights reserved.

Evaluation of the genotoxicity of Crotalus durissus terrificus snake venom and its isolated toxins on human lymphocytes

In the present study, experiments were carried out to evaluate the mutagenic potential and genotoxic effects of Crotalus durissus terrificus snake venom and its isolated toxins on human lymphocytes, using the micronucleus and comet assays. Significant damage to DNA was observed for crotoxin and crotapotin (CA). Basic phospholipase A(2) (CB) and crotamine did not present any mutagenic potential when evaluated by the micronucleus test. C. d. terrificus crude venom was able to induce the formation of micronuclei, similarly to the mutagenic drug used as a positive control. In the comet assay, all the toxins tested (crotamine, crotoxin, CB and CA) and C. d. terrificus venom presented genotoxic activity. Studies on the cytogenetic toxicology of animal venoms and their isolated proteins are still very scarce in the literature, which emphasizes the importance of the present work for the identification and characterization of potential therapeutic agents, as well as for the better understanding of the mechanisms of action of toxins on the human body. (C) 2011 Elsevier B.V. All rights reserved.

Evaluation of Environmental Mycobacteria Contamination in a Specific Pathogen Free Animal Facility from a Tropical Country

P>With the evidence showing the protection variability of bacille Calmette-Guerin, new potential vaccines for tuberculosis have been tested around the world. One of the general concerns in tuberculosis vaccine development is the possibility of priming the host immune system with prior exposure to environmental mycobacteria antigens, which can change the efficacy of subsequent vaccination. As there is a great homology between the species from Mycobacterium genera, the previous contact of experimental animals with environmental mycobacteria could sensitize the mice and, in this way, could influence subsequent vaccine research. The aim of our study was to investigate critical points in an animal facility to search for environmental mycobacteria that eventually could be in direct or indirect contact with the experimental animals. Samples were collected from surfaces of walls, floor, animal cages and shelves and analysed using the Ogawa-Kudoh decontamination method. Samples of drinking water, food and sawdust were collected for analysis by the NALC/NaOH decontamination method. Also, the samples were cultivated directly in broth medium, without any method for decontamination. After decontamination methods, we observed bacterial colony growth in 4.31% of the total of samples analysed. These samples were stained with Ziehl-Neelsen and we did not detect any acid-fast bacilli, suggesting that the animal facility analysed is free from contamination by environmental mycobacteria and is not a source of mycobacterial antigens. Furthermore, our study showed a new paradigm in tuberculosis vaccine development: concern about the animal facility environment in terms of immune system priming of experimental animals by nascent bacterial contaminants.