Real-time Polymerase Chain Reaction Quantification of Porphyromonas gingivalis and Tannerella forsythia in Primary Endodontic Infections

Introduction: Porphyromonas gingivalis and Tannerella forsythia are anaerobic bacteria commonly involved in root canal infections. Although previous investigations have assessed these species by strictly qualitative approaches, accurate determination of their cell levels by a sensitive quantitative technique may contribute with additional information regarding relevance in pain of endodontic origin. Method: The root canal levels of P gingivalis, T forsythia, and total bacteria were investigated by a quantitative polymerase chain reaction (PCR) assay based on unique copy molecular markers. A total of 32 symptomatic (n = 14) and asymptomatic (n = 18) cases of endodontic infections were analyzed. Root canal samples were collected; genomic DNA was extracted and submitted to SYBR Green I real-time PCR targeting the rgpB (P gingivalis), bspA (T forsythia), and rpoB (total bacteria) single copy genes. Results: Overall, R gingivalis, T forsythia, and the coexistence of both species were encountered in 28%, 66%, and 22% of the subjects, respectively. P gingivalis and T forsythia levels ranged from 5.65 x 10(-6) to 1.20 x 10(-2) and from 5.76 x 10(-6) to 1.35 x 10(-1). T forsythia was highly prevalent and numerous in the study groups, whereas P gingivalis was moderately frequent and less abundant, displaying 19-fold lower average levels than the former. Conclusions: The endodontic levels of P gingivalis and T forsythia, individually or in conjunction, did not display significant associations with the manifestation of pain of endodontic origin. (J Endod 2009,35:1518-1524)

Growth and haematology of pacu, Piaractus mesopotamicus, fed diets with varying protein to energy ratio

Haematopoiesis and blood cells` functions can be influenced by dietary concentration of nutrients. This paper studied the effects of dietary protein:energy ratio on the growth and haematology of pacu, Piaractus mesopotamicus. Fingerling pacu (15.5 +/- 0.4 g) were fed twice a day for 10 weeks until apparent saciety with diets containing 220, 260, 300, 340 or 380 g kg(-1) crude protein (CP) and 10.88, 11.72, 12.55, 13.39, 14.22 MJ kg(-1) digestible energy (DE) in a totally randomized experimental design, 5 x 5 factorial scheme (n=3). Weight gain and specific growth rate were affected (P < 0.05) by protein level only. Protein efficiency ratio decreased (P < 0.05) with increasing dietary protein at all levels of dietary energy. Daily feed intake decreased (P < 0.05) with increasing dietary energy. Mean corpuscular haemoglobin concentration was affected (P < 0.05) by DE and interaction between dietary CP and DE. Total plasma protein increased (P < 0.05) with dietary protein and energy levels. Plasma glucose decreased (P < 0.05) with increasing dietary protein. The CP requirement and optimum protein:energy ratio for weight gain of pacu fingerlings, determined using broken-line model, were 271 g kg(-1) and 22.18 g CP MJ(-1) DE respectively. All dietary CP and DE levels studied did not pose damages to fish health.

Feeding Dietary Mannan Oligosaccharides to Juvenile Nile Tilapis, Oreochromis niloticus, Has No Effect on Hematological Parameters and Showed Decreased Feed Consumption

Impaired immune system by environmental stressors can lead fishes to be more susceptible to diseases that limit the economic development of aquaculture systems. This study was set out to determine the effect of six levels of mannan oligosaccharides (MOS; ActiveMOS((R)); Biorigin, Lencois Paulista, Sao Paulo, Brazil) on the performance index and hematology of Nile tilapia, Oreochromis niloticus juveniles. Fish (13.62 g) were randomly distributed into 18 plastic aquaria (300 L; 20 fishes per aquarium) and fed during 45 d with a commercial diet supplemented with 0, 0.2, 0.4, 0.6, 0.8, and 1% dietary MOS, in a totally randomized design trial (n = 3); biometrical and hematological data were collected and analyzed. There were no significant differences in hematological parameters between fish fed control and MOS supplementation diets, and daily feed consumption (FC) decreased (P < 0.05) with increasing levels of dietary MOS. Dietary MOS did not increase leukocyte count and presented negative effects on FC of Nile tilapia. At 0.4% MOS supplementation, the individual weight gain was higher in absolute values but not different (P > 0.05) compared to control diet.

Effect of the Gamma Radiation Dose Rate on Psychrotrophic Bacteria, Thiobarbituric Acid Reactive Substances, and Sensory Characteristics of Mechanically Deboned Chicken Meat

Frozen samples of mechanically deboned chicken meat (MDCM) with skin were irradiated with gamma radiation doses of 0.0 kGy (control) and 3 kGy at 2 different radiation dose rates: 0.32 kGy/h (3 kGy) and 4.04 kGy/h (3 kGy). Batches of irradiated and control samples were evaluated during 11 d of refrigerated (2 +/- 1 degrees C) storage for the following parameters: total psychrotrophic bacteria count, thiobarbituric acid reactive substances (TBARS), evaluation of objective color (L*, a*, and b*) and a sensory evaluation (irradiated odor, oxidized odor, pink and brown colors). No statistical difference (P > 0.05) was found amongst the TBARS values obtained for the MDCM samples irradiated with dose rates of 0.32 and 4.04 kGy/h. There was a significant increase (P < 0.05) in the psychrotrophic bacterial count as from the 7th day of refrigerated storage, for the MDCM samples irradiated at the dose rate of 4.04 kGy/h. With respect to the attribute of oxidized odor, the samples irradiated with a dose rate of 0.32 kGy/h showed a stronger intensity and were significantly different (P < 0.05) from the sample irradiated with a dose rate of 4.04 kGy/h on days 0 and 2 of refrigerated storage. Irradiation with a dose rate of 4.04 kGy/h (3 kGy) was shown to be the best condition for the processing of MDCM according to the evaluation of all the variables, under the conditions of this study. Practical Application The results obtained for the application of different dose rates of ionizing radiation to mechanically deboned chicken meat will provide the food industry with information concerning the definition of the best processing conditions to maximize the sensory and food quality.

Leaf area index estimation with MODIS reflectance time series and model inversion during full rotations of Eucalyptus plantations

The leaf area index (LAI) of fast-growing Eucalyptus plantations is highly dynamic both seasonally and interannually, and is spatially variable depending on pedo-climatic conditions. LAI is very important in determining the carbon and water balance of a stand, but is difficult to measure during a complete stand rotation and at large scales. Remote-sensing methods allowing the retrieval of LAI time series with accuracy and precision are therefore necessary. Here, we tested two methods for LAI estimation from MODIS 250m resolution red and near-infrared (NIR) reflectance time series. The first method involved the inversion of a coupled model of leaf reflectance and transmittance (PROSPECT4), soil reflectance (SOILSPECT) and canopy radiative transfer (4SAIL2). Model parameters other than the LAI were either fixed to measured constant values, or allowed to vary seasonally and/or with stand age according to trends observed in field measurements. The LAI was assumed to vary throughout the rotation following a series of alternately increasing and decreasing sigmoid curves. The parameters of each sigmoid curve that allowed the best fit of simulated canopy reflectance to MODIS red and NIR reflectance data were obtained by minimization techniques. The second method was based on a linear relationship between the LAI and values of the GEneralized Soil Adjusted Vegetation Index (GESAVI), which was calibrated using destructive LAI measurements made at two seasons, on Eucalyptus stands of different ages and productivity levels. The ability of each approach to reproduce field-measured LAI values was assessed, and uncertainty on results and parameter sensitivities were examined. Both methods offered a good fit between measured and estimated LAI (R(2) = 0.80 and R(2) = 0.62 for model inversion and GESAVI-based methods, respectively), but the GESAVI-based method overestimated the LAI at young ages. (C) 2010 Elsevier Inc. All rights reserved.

MODIS NDVI time-series allow the monitoring of Eucalyptus plantation biomass

The use of remote sensing is necessary for monitoring forest carbon stocks at large scales. Optical remote sensing, although not the most suitable technique for the direct estimation of stand biomass, offers the advantage of providing large temporal and spatial datasets. In particular, information on canopy structure is encompassed in stand reflectance time series. This study focused on the example of Eucalyptus forest plantations, which have recently attracted much attention as a result of their high expansion rate in many tropical countries. Stand scale time-series of Normalized Difference Vegetation Index (NDVI) were obtained from MODIS satellite data after a procedure involving un-mixing and interpolation, on about 15,000 ha of plantations in southern Brazil. The comparison of the planting date of the current rotation (and therefore the age of the stands) estimated from these time series with real values provided by the company showed that the root mean square error was 35.5 days. Age alone explained more than 82% of stand wood volume variability and 87% of stand dominant height variability. Age variables were combined with other variables derived from the NDVI time series and simple bioclimatic data by means of linear (Stepwise) or nonlinear (Random Forest) regressions. The nonlinear regressions gave r-square values of 0.90 for volume and 0.92 for dominant height, and an accuracy of about 25 m(3)/ha for volume (15% of the volume average value) and about 1.6 m for dominant height (8% of the height average value). The improvement including NDVI and bioclimatic data comes from the fact that the cumulative NDVI since planting date integrates the interannual variability of leaf area index (LAI), light interception by the foliage and growth due for example to variations of seasonal water stress. The accuracy of biomass and height predictions was strongly improved by using the NDVI integrated over the two first years after planting, which are critical for stand establishment. These results open perspectives for cost-effective monitoring of biomass at large scales in intensively-managed plantation forests. (C) 2011 Elsevier Inc. All rights reserved.

A new set of microsatellite markers for the genetic characterization of Ceratocystis fimbriata, an economically important plant pathogen

Ceratocystis fimbriata is a fungal pathogen which attacks several economically important plants, but occurs in host-associated, morphologically indistinguishable forms. In Brazil, this fungus seriously attacks mango trees (Mangifera indica), causing severe loss of yield. This work aimed to develop and characterize a novel set of microsatellite markers for this important pathogen, providing researchers with new molecular tools for the characterization of isolates. Twenty polymorphic primer pairs were designed from a microsatellite-enriched library. We tested the usefulness of these markers through genotyping thirteen isolates of the fungus. On average, 6.65 alleles per locus were detected, revealing the ability of this set of markers to characterize C. fimbriata isolates associated to mango and to other plant species.

Evaluation of two semi-selective media to detect Curtobacterium flaccumfaciens pv. flaccumfaciens in bean seeds

Evaluation of two semi-selective media to detect Curtobacterium flaccumfaciens pv. flaccumfaciens in bean seeds This study aimed to compare the effectiveness of the semi-selective MSCFF and modified CNS culture media in detecting Curtobacterium flaccumfaciens pv. flaccumfaciens (Cff) in bean seeds, using the streak and spread plate techniques. Four 500 g subsamples, obtained from two samples of bean seeds, were immersed in 600 mL of sterile distilled water for 18 h at 5 degrees C. Suspensions were picked and transferred to plates with both culture media. Plates were then incubated at 28 degrees C, and bacterial growth on both media was evaluated 72 and 144 hours later, compared to the growth of a Cff reference strain. Both media revealed the presence of Cff colonies. Typical colonies were isolated for PCR analyses and pathogenicity tests on tobacco leaves. A characteristic Cff growth on MSCFF medium was observed for the seed samples, for the two plate techniques used, in both evaluations. On the modified CNS culture medium, the bacterial growth was only detected in seed samples after 144 hours of incubation, regardless of the plate technique used. The results showed Cff grew faster on the MSCFF semi-selective culture medium. Bacterial isolates tested were identified as Cff by both PCR analyses and a positive tobacco hypersensitivity reaction.

Test procedure for variable rate fertilizer on coffee

The objective was to develop and test a procedure for applying variable rates of fertilizers and evaluate yield response in coffee (Coffea arabica L.) with regard to the application of phosphorus and potassium. The work was conducted during the 2004 season in a 6.4 ha field located in central Sao Paulo state. Two treatments were applied with alternating strips of fixed and variable rates during the whole season: one following the fertilizing procedures recommended locally, and the other based on a grid soil sampling. A prototype pneumatic fertilizer applicator was used, carrying two conveyor belts, one for each row. Harvesting was done with a commercial harvester equipped with a customized volumetric yield monitor, separating the two treatments. Data were analyzed based on geostatistics, correlations and regressions. The procedure showed to be feasible and effective. The area that received fertilizer applications at a variable rate showed a 34% yield increase compared to the area that received a fixed rate. The variable rate fertilizer resulted in a savings of 23% in phosphate fertilizer and a 13% increase in potassium fertilizer, when compared to fixed rate fertilizer. Yield in 2005, the year after the variable rate treatments, still presented residual effect from treatments carried out during the previous cycle.

Greenhouse gases emission from soil contaminated with automobile industry residue in Brazil

Solid waste of the automobile industry containing large amounts of heavy metals might affect the emission of greenhouse gases (GHG) when applied to the soil. Accumulation of inorganic chemical elements in the environment generally occurs due to human activity (industry, agriculture, mining and waste landfills). Residues from human activities may release heavy metals to the soil solution, causing toxicity to plants and other soil organisms. Heavy metals may also be adsorbed to clay minerals and/or complexed by the soil organic matter, becoming a potential source of pollutants. Not much is known about the behavior of solid wastes in tropical soil as regarded as source of greenhouse gases (GHG). The emission of GHG (CO(2), CH(4) and N(2)O) was evaluated in incubated soil samples collected in an area contaminated with a solid residue from an automobile industry. Samples were randomly collected at 0 to 0.2 m (a mix of soil and residue), 0.2 to 0.4 m (only residue) and 0.4 to 0.6 m (only soil). A contiguous uncontaminated area, cultivated with sugarcane, was also sampled following the same protocol. Canonical Discriminant Analysis and Principal Component Analysis were applied to the data to evaluate the GHG emission rates. Emission rates of GHG were greater in the samples from the contaminated than the sugarcane area, particularly high during the first days of incubation. CO(2) emissions were greater in samples collected at the upper layer for both areas, while CH(4) and N(2)O emissions were similar in all samples. The emission rates of CH(4) were the most efficient variables to differentiate contaminated and uncontaminated areas.

Determination of the median lethal concentration (LC(50)) of mycoinsecticides for the control of Ceratitis capitata (Diptera: Tephritidae)

The aim of this study was to determine the median lethal concentration (LC(50)) of the commercial products Boveril WP (R) (Beauveria bassiana) and Metarril WP (R) (Metarhizium anisopliae) on the larvae and pupae of the fruit Ceratitis capitata. Insects used in this study came from a laboratory colony. The evaluated product concentrations were 10.00, 15.00, 20.00 and 25.00 g/L of water, which correspond, respectively, to 5.00x10(9), 7.50x10(9), 10.00x10(9) and 12.50x10(9) viable conidia/L of water for the two products, and in the control only water was applied. Third instar larvae and pupae of C. capitata were used in this study. Results showed an overall mortality of larvae with all conidial concentrations of M. anisopliae. The LC(50) values for larvae were 2.99 and 2.97 g/L for Boveril (R) and Metarril (R), respectively, while for pupae they were 3.12 and 4.74 g/L for Boveril (R) and Metarril (R), respectively. The high pathogenicity demonstrated by lower conidial concentrations of the tested products may mean greater efficiency from both economic and environmental points of view.

Micronutrient dynamics in the forest biomass in succession stages of a seasonal deciduous forest, RS, Brazil

There is a great need of research to assess the behavior of micronutrients in natural forests of southern Brazil. Do to this need, the objective of this work was to study the levels and amounts of micronutrients in forest above ground biomass of the forest, in a comparative way, in two secondary succession stages (SSS) in a Seasonal Deciduous Forest in Rio Grande do Sul, Brazil. The SSS had enjoyed 35 and 55 years of regeneration since the end of agricultural use, respectively for initial secondary forest (ISF) and late secondary forest (LSF). The above-ground biomass was collected and separated into vegetative strata and these in fractions, thereafter chemically analyzed for the levels of B, Fe, Zn, Mn and Cu. Leaf fractions of arboreal, shrubs and herbaceous strata showed the highest levels for most nutrients. Only the levels of iron and manganese were higher in the bark fraction, for both sucession stages. In the LSF, the herbaceous stratum also showed high levels of Fe. The average levels of micronutrients showed differences between the two sucession stages only in relation to Fe and Mn, with higher levels in LSF biomass. The amount of nutrients stored was always higher in LSF, because of the largest biomass and the higher levels of Fe and Mn in the biomass of this SSS. The quantitative order of nutrient storage in biomass was Fe> Mn> Zn> B> Cu.

Relating MODIS vegetation index time-series with structure, light absorption and stem production of fast-growing Eucalyptus plantations

By allowing the estimation of forest structural and biophysical characteristics at different temporal and spatial scales, remote sensing may contribute to our understanding and monitoring of planted forests. Here, we studied 9-year time-series of the Normalized Difference Vegetation Index (NDVI) from the Moderate Resolution Imaging Spectroradiometer (MODIS) on a network of 16 stands in fast-growing Eucalyptus plantations in Sao Paulo State, Brazil. We aimed to examine the relationships between NDVI time-series spanning entire rotations and stand structural characteristics (volume, dominant height, mean annual increment) in these simple forest ecosystems. Our second objective was to examine spatial and temporal variations of light use efficiency for wood production, by comparing time-series of Absorbed Photosynthetically Active Radiation (APAR) with inventory data. Relationships were calibrated between the NDVI and the fractions of intercepted diffuse and direct radiation, using hemispherical photographs taken on the studied stands at two seasons. APAR was calculated from the NDVI time-series using these relationships. Stem volume and dominant height were strongly correlated with summed NDVI values between planting date and inventory date. Stand productivity was correlated with mean NDVI values. APAR during the first 2 years of growth was variable between stands and was well correlated with stem wood production (r(2) = 0.78). In contrast, APAR during the following years was less variable and not significantly correlated with stem biomass increments. Production of wood per unit of absorbed light varied with stand age and with site index. In our study, a better site index was accompanied both by increased APAR during the first 2 years of growth and by higher light use efficiency for stem wood production during the whole rotation. Implications for simple process-based modelling are discussed. (C) 2009 Elsevier B.V. All rights reserved.

Development and characterization of microsatellite markers for castor (Ricinus communis L.), an important oleaginous species for biodiesel production

Castor (Ricinus communis L.) is an important oleaginous plant from both economic and social points of view. The seeds contain an oil with excellent properties for industrial uses. This paper presents the main results of a study aiming to develop microsatellite markers for castor. Twelve new polymorphic microsatellite markers were isolated and characterized in 38 genotypes accessions from the castor germplasm of the Brazilian Agricultural Research Company (EMBRAPA). Knowledge on the genetic diversity of castor can be used to gain a better understanding on genetic diversity conservation, and germplasm management, guiding breeding programs and conservation strategies.

Relationship between occurrence of Panama disease in banana trees of cv. Nanicao and nutrients in soil and leaves

Relationship between occurrence of Panama disease in banana trees of cv. Nanicao and nutrients in soil and leaves The objective of the present work was to verify if the incited symptoms in banana trees cv. Nanicao, belonging to the subgroup Cavendish, in Vale do Ribeira, are related to levels of nutrients in soil and leaves. Sixteen areas in Vale do Ribeira were selected, one half with symptomatic plants and the other with healthy plants. In those areas the third leaf of five plants and the soil near those plants were collected, at depths from 0 to 20 cm and from 20 to 40 cm. At both depths of the sampled soil, levels of Ca, Mg, PO(4)(-3), S and cationic exchange capacity (CEC) were significantly different among the areas, and the low values of these elements were present in the areas containing symptomatic plants. At both depths, Mg, Al and H in relation to CEC were significantly different among the areas, and the low values of Mg and high of Al and H were present in the areas with symptomatic plants. The N, K and S in the leaves were significantly different among the areas. These elements showed low values in the areas containing symptomatic plants. Despite the fact that some amounts of macronutrients of the soil and of the leaves are present only in the areas containing plants of Nanicao with symptoms similar to fusariosis, proof of a possible occurrence of race of the pathogen should be looked for in Vale do Ribeira.