Modeling soil organic carbon dynamics in Oxisols of Ibiruba (Brazil) with the Century Model

introduction of conservation practices in degraded agricultural land will generally recuperate soil quality, especially by increasing soil organic matter. This aspect of soil organic C (SOC) dynamics under distinct cropping and management systems can be conveniently analyzed with ecosystem models such as the Century Model. In this study, Century was used to simulate SOC stocks in farm fields of the Ibiruba region of north central Rio Grande do Sul state in Southern Brazil. The region, where soils are predominantly Oxisols, was originally covered with subtropical woodlands and grasslands. SOC dynamics was simulated with a general scenario developed with historical data on soil management and cropping systems beginning with the onset of agriculture in 1900. From 1993 to 2050, two contrasting scenarios based on no-tillage soil management were established: the status quo scenario, with crops and agricultural inputs as currently practiced in the region and the high biomass scenario with increased frequency of corn in the cropping system, resulting in about 80% higher biomass addition to soils. Century simulations were in close agreement with SOC stocks measured in 2005 in the Oxisols with finer texture surface horizon originally under woodlands. However, simulations in the Oxisols with loamy surface horizon under woodlands and in the grassland soils were not as accurate. SOC stock decreased from 44% to 50% in fields originally under woodland and from 20% to 27% in fields under grasslands with the introduction of intensive annual grain crops with intensive tillage and harrowing operations. The adoption of conservation practices in the 1980s led to a stabilization of SOC stocks followed by a partial recovery of native stocks. Simulations to 2050 indicate that maintaining status quo would allow SOC stocks to recover from 81% to 86% of the native stocks under woodland and from 80% to 91 % of the native stocks under grasslands. Adoption of a high biomass scenario would result in stocks from 75% to 95% of the original stocks under woodlands and from 89% to 102% in the grasslands by 2050. These simulations outcomes underline the importance of cropping system yielding higher biomass to further increase SOC content in these Oxisols. This application of the Century Model could reproduce general trends of SOC loss and recovery in the Oxisols of the Ibiruba region. Additional calibration and validation should be conducted before extensive usage of Century as a support tool for soil carbon sequestration projects in this and other regions can be recommended. (C) 2009 Elsevier B.V. All rights reserved.

Tillering dynamics in palisadegrass swards continuously stocked by cattle

Plant communities on pastures adapt to varying frequencies and severities of defoliation through mechanisms capable of ensuring their longevity and photosynthetic efficiency. The objective of this experiment was to evaluate tiller population density, demographic patterns of tillering and population stability of palisadegrass swards subjected to four grazing intensities. Treatments corresponded to four sward steady state conditions (sward heights of 10, 20, 30 and 40 cm) generated by continuous stocking. Measurements of tiller population density and population dynamics were performed at 4 week intervals and the results were used to calculate tiller appearance, death and survival rates. Tiller appearance and death rate were used to calculate sward stability index. The results indicate that keeping swards low (10 cm or lower) may be prejudicial to persistency and productivity of palisadegrass. The results also indicate that a low tiller population alone should not be considered as an indicator of loss of productive potential and of reduced plant persistency, since swards may be stable even with low population of tillers.

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.

Influence of magnesium status and magnesium intake on the blood glucose control in patients with type 2 diabetes

Background & aims: This study was undertaken to assess magnesium intake and magnesium status in patients with type 2 diabetes, and to identify the parameters that best predict alterations in fasting glucose and plasma magnesium. Methods: A cross-sectional study was carried out in patients with type 2 diabetes (n = 51; 53.6 +/- 10.5 y) selected within the inclusion factors, at the University Hospital Onofre Lopes. Magnesium intake was assessed by three 24-h recalls. Urine, plasma and erythrocytes magnesium, fasting and 2-h postprandial glucose, HbA1, microalbuminuria, proteinuria, and serum and urine creatinine were measured. Results: Mean magnesium intake (9.37 +/- 1.76 mmol/d), urine magnesium (2.80 +/- 1.51 mmol/d), plasma magnesium (0.71 +/- 0.08 mmol/L) and erythrocyte magnesium (1.92 +/- 0.23 mmol/L) levels were low. Seventy-seven percent of participants presented one or more magnesium status parameters below the cut-off points of 3.00 mmol/L for urine, 0.75 mmol/L for plasma and 1.65 mmol/L for erythrocytes. Subjects presented poor blood glucose control with fasting glucose of 8.1 +/- 3.7 mmol/L, 2-h postprandial glucose of 11.1 +/- 5.1 mmol/L, and HbA1 of 11.4 +/- 3.0%. The parameters that influenced fasting glucose were urine, plasma and dietary magnesium, while plasma magnesium was influenced by creatinine clearance. Conclusions: Magnesium status was influenced by kidney depuration and was altered in patients with type 2 diabetes, and magnesium showed to play an important role in blood glucose control. (C) 2011 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Biomarkers of metabolic syndrome and its relationship with the zinc nutritional status in obese women

Introduction: Obesity is a chronic disease that induces risk factors for metabolic syndrome and, is associated with disturbances in the metabolism of the zinc. Therefore, the aim of this study was to investigate the existence of relationship between the biomarkers of metabolic syndrome and the zinc nutricional status in obese women. Method: Seventy-three premenopausal women, aged between 20 and 50 years, were divided into two groups: case group, composed of obese (n = 37) and control group, composed of no obese (n = 36). The assessment of the body mass index and waist circumference were carried out using anthropometric measurements. The plasmatic and erythrocytary zinc were analyzed by method atomic absorption spectrophotometry (lambda=213.9 nm). Results: In the study, body mass index and waist circumference were higher in obese women than control group (p < 0.05). The mean plasmatic zinc was 72.2 +/- 9.0 mu g/dl in obese women and 73.4 +/- 8.5 mu g/dl in control group (p > 0.05). The mean erythrocytary zinc was 36.4 +/- 15.0 mu g/gHb and 45.4 +/- 14.3 mu g/gHb in the obese and controls, respectively (p < 0.05). Regression analysis showed that the body mass index (t=-2.85) and waist circumference (t=-2.37) have a negative relationship only with the erythrocytary zinc (R(2)=0.32, p < 0.05). Conclusions: The study shows that there are alterations in biochemical parameters of zinc in obese women, with low zinc concentrations in erythrocytes. Regression analysis demonstrates that the erythrocytary zinc is influenced by biomarkers of the metabolic syndrome, presenting an inverse relationship with the waist circumference and body mass index.

Cloning, characterization and functional analysis of a 1-FEH cDNA from Vernonia herbacea (Vell.) Rusby

Variations in the inulin contents have been detected in rhizophores of Vernonia herbacea during the phenological cycle. These variations indicate the occurrence of active inulin synthesis and depolymerization throughout the cycle and a role for this carbohydrate as a reserve compound. 1-Fructan exohydrolase (1-FEH) is the enzyme responsible for inulin depolymerization, and its activity has been detected in rhizophores of sprouting plants. Defoliation and low temperature are enhancer conditions of this 1-FEH activity. The aim of the present work was the cloning of this enzyme. Rhizophores were collected from plants induced to sprout, followed by storage at 5C. A full length 1-FEH cDNA sequence was obtained by PCR and inverse PCR techniques, and expressed in Pichia pastoris. Cold storage enhances FEH gene expression. Vh1-FEH was shown to be a functional 1-FEH, hydrolyzing predominantly -2,1 linkages, sharing high identity with chicory FEH sequences, and its activity was inhibited by 81 in the presence of 10 mM sucrose. In V. herbacea, low temperature and sucrose play a role in the control of fructan degradation. This is the first study concerning the cloning and functional analysis of a 1-FEH cDNA of a native species from the Brazilian Cerrado. Results will contribute to understanding the role of fructans in the establishment of a very successful fructan flora of the Brazilian Cerrado, subjected to water limitation and low temperature during winter.

Abnormal Neurovascular Control in Anabolic Androgenic Steroids Users

NUNES ALVES, M. J. N., M. R. DOS SANTOS, R. G. DIAS, C. A. AKIHO, M. C. LATERZA, M. U. P. B. RONDON, R. L. DE MORAES MOREAU, and C. E. NEGRAO. Abnormal Neurovascular Control in Anabolic Androgenic Steroids Users. Med. Sci. Sports Exerc., Vol. 42, No. 5, pp. 865-871, 2010. Purpose: Previous studies showed that anabolic androgenic steroids (AAS) increase vascular resistance and blood pressure (BP) in humans. In this study, we tested the hypotheses 1) that AAS users would have increased muscle sympathetic nerve activity (MSNA) and reduced forearm blood flow (FBF) compared with AAS nonusers and 2) that there would be an association between MSNA and 24-h BP. Methods: Twelve AAS users aged 31 +/- 2 yr (means +/- SE) and nine age-matched AAS nonusers aged 29 T 2 yr participated in the study. All individuals were involved in strength training for at least 2 yr. AAS was determined by urine test (chromatography-mass spectrometry). MSNA was directly measured by microneurography technique. FBF was measured by venous occlusion plethysmography. BP monitoring consisted of measures of BP for 24 h. Results: MSNA was significantly higher in AAS users than that in AAS nonusers (29 +/- 3 vs 20 +/- 1 bursts per minute, P = 0.01). FBF (1.92 +/- 0.17 vs 2.77 +/- 0.24 mL.min(-1).100 mL(-1), P = 0.01) and forearm vascular conductance (2.01 +/- 0.17 vs 2.86 +/- 0.31 U, P = 0.02) were significantly lower in AAS users than that in AAS nonusers. Systolic (131 +/- 4 vs 120 +/- 3 mm Hg, P = 0.001), diastolic (74 +/- 4 vs 68 +/- 3 mm Hg, P = 0.02), and mean BP (93 +/- 4 vs 86 +/- 3 mm Hg, P = 0.005) and heart rate (74 +/- 3 vs 68 +/- 3 bpm, P = 0.02) were significantly higher in AAS users when compared with AAS nonusers. Further analysis showed that there was a significant correlation between MSNA and 24-h mean BP (r = 0.75, P = 0.002). Conclusions: AAS increases MSNA and reduces muscle blood flow in young individuals. In addition, the increase in BP levels in AAS users is associated with augmented sympathetic outflow. These findings suggest that AAS increases the susceptibility for cardiovascular disease in humans.

RECK-Mediated Inhibition of Glioma Migration and Invasion

RECK is an anti-tumoral gene whose activity has been associated with its inhibitory effects regulating MMP-2, MMP-9, and MT1-MMP. RECK level decreases as gliobastoma progresses, varying from less invasive grade II gliomas to very invasive human glioblastoma multiforme (GBM). Since RECK expression and glioma invasiveness show an inverse correlation, the aim of the present study is to investigate whether RECK expression would inhibit glioma invasive behavior. We conducted this study to explore forced RECK expression in the highly invasive T98G human GBM cell line. Expression levels as well as protein levels of RECK, MMP-2, MMP-9, and MT1-MMP were assessed by qPCR and immunoblotting in T98G/RECK+ cells. The invasion and migration capacity of RECK+ cells was inhibited in transwell and wound assays. Dramatic cytoskeleton modifications were observed in the T98G/RECK+ cells, when compared to control cells, such as the abundance of stress fibers (contractile actin-myosin II bundles) and alteration of lamellipodia. T98G/RECK+ cells also displayed phosphorylatecl focal adhesion kinase (P-FAK) in mature focal adhesions associated with stress fibers; whereas P-FAK in control cells was mostly associated with immature focal complexes. Interestingly, the RECK protein was predominantly localized at the leading edge of migrating cells, associated with membrane ruffles. Unexpectedly, introduced expression of RECK effectively inhibited the invasive process through rearrangement of actin filaments, promoting a decrease in migratory ability. This work has associated RECK tumor-suppressing activity with the inhibition of motility and invasion in this GBM model, which are two glioma characteristics responsible for the inefficiency of current available treatments. J. Cell. Biochem. 110: 52-61, 2010. (C) 2010 Wiley-Liss. Inc.

Effects of isoflavone-supplemented soy yogurt on lipid parameters and atherosclerosis development in hypercholesterolemic rabbits: a randomized double-blind study

Background: There is increasing interest in natural treatments to control dyslipidemia and reduce the risk of cardiovascular disease. Previous studies have demonstrated the beneficial effects of soy yogurt fermented with Enterococcus faecium CRL 183 and of dietary isoflavones on the lipid profile. The purpose of the present study was to investigate the effects of isoflavone-supplemented soy yogurt, fermented with E. faecium CRL183, on lipid parameters and atherosclerosis development in rabbits with induced hypercholesterolemia. Methods: Forty-eight rabbits were randomly assigned to eight groups fed on the following diets for 60 days: C - control; IY - isoflavone-supplemented soy yogurt; H - hypercholesterolemic (1.0% cholesterol wt/wt diet); HY - hypercholesterolemic plus soy yogurt; HIY - hypercholesterolemic plus isoflavone-supplemented soy yogurt; HP - hypercholesterolemic plus placebo; HI hypercholesterolemic plus isoflavone and HE - hypercholesterolemic plus pure culture of E. faecium CRL 183. Serum lipids and autoantibodies against oxLDL (oxLDL Ab) were analyzed on days 0, 30 and 60 of the treatment and the atherosclerotic lesions were quantified at the end of the experiment. Results: Soy yogurt, soy yogurt supplemented with isoflavones and placebo promoted significant reductions in total cholesterol level (38.1%, 27.0% and 26.6%, respectively). Significant increases in serum HDL-C concentration relative to group H were detected in animals that ingested soy yogurt, with or without the isoflavone supplement (55.2%), E. faecium culture (43.3%) or placebo (35.8%). Intake of soy yogurt and soy yogurt supplemented with isoflavones prevented the rise of oxLDL Ab during the study period. The extent of atherosclerosis in the thoracic and abdominal aortas was reduced in the HIY, HY and HP groups. However, when the whole aorta was analyzed, animals treated with soy yogurt supplemented with isoflavones exhibited the greatest reduction (51.4%, P < 0.05) in atherosclerotic lesion area, compared to group H. Conclusion: Soy yogurt could be consumed as an alternative means of reducing the risk of cardiovascular disease by improving the lipid profile and inhibiting oxLDL Ab formation. Our findings also suggest that isoflavone supplementation may enhance the antiatherosclerotic effect of soy yogurt.

Detection of the TLR4 1196C > T Polymorphism by Mismatched-Polymerase Chain Reaction Using Plasmid DNA as Internal Control in Restriction Fragment Length Polymorphism Assays

Background: Restriction fragment length polymorphism (RFLP) is a common molecular assay used for genotyping, and it requires validated quality control procedures to prevent mistyping caused by impaired endonuclease activity. We have evaluated the usefulness of a plasmid-based internal control in RFLP assays. Results: Blood samples were collected from 102 individuals with acute myocardial infarction (AMI) and 108 non-AMI individuals (controls) for DNA extraction and laboratory analyses. The 1196C> T polymorphism in the toll-like receptor 4 (TLR4) gene was amplified by mismatched-polymerase chain reaction (PCR). Amplicons and pBluescript II SK-plasmid were simultaneously digested with endonuclease HincII. Fragments were separated on 2% agarose gels. Plasmid was completely digested using up to 55.2 nmL/L DNA solutions and 1 mu L PCR product. Nevertheless, plasmid DNA with 41.4 nM or higher concentrations was incompletely digested in the presence of 7 mL PCR product. In standardized conditions, TLR4 1196C> T variant was accurately genotyped. TLR4 1196T allele frequency was similar between AMI (3.1%) and controls (2.0%, p = 0.948). TLR4 SNP was not associated with AMI in this sample population. In conclusion, the plasmid-based control is a useful approach to prevent mistyping in RFLP assays, and it is validate for genetic association studies such as TLR4 1196C> T.

Influence of ammonium sulphate feeding time on fed-batch Arthrospira (Spirulina) platensis cultivation and biomass composition with and without pH control

Previous work demonstrated that a mixture of NH(4)Cl and KNO(3) as nitrogen source was beneficial to fed-batch Arthrospira (Spirulina) platensis cultivation, in terms of either lower costs or higher cell concentration. On the basis of those results, this study focused on the use of a cheaper nitrogen source mixture, namely (NH(4))(2)SO(4) plus NaNO(3), varying the ammonium feeding time (T = 7-15 days), either controlling the pH by CO(2) addition or not. A. platensis was cultivated in mini-tanks at 30 degrees C, 156 mu mol photons m(-2) s(-1), and starting cell concentration of 400 mg L(-1), on a modified Schlosser medium. T = 13 days under pH control were selected as optimum conditions, ensuring the best results in terms of biomass production (maximum cell concentration of 2911 mg L(-1), cell productivity of 179 mg L(-1) d(-1) and specific growth rate of 0.77 d(-1)) and satisfactory protein and lipid contents (around 30% each). (C) 2011 Elsevier Ltd. All rights reserved.

Sterilization of Medical Devices by Ethylene Oxide, Determination of the Dissipation of Residues, and Use of Green Fluorescent Protein as an Indicator of Process Control

Ethylene oxide (EO) is used to sterilize Oxygenator and Tubing applied to heart surgery. Residual levels of EO and its derivatives, ethylene chlorohydrin (ECH) and ethylene glycol (EG), may be hazardous to the patients. Therefore, it must be removed by the aeration process. This study aimed to estimate the minimum aeration time for these devices to attain safe limits for use (avoiding excessive aeration time) and to evaluate the Green Fluorescent Protein (GFP) as a biosensor capable of best indicating the distribution and penetration of EO gas throughout the sterilization chamber. Sterilization cycles of 2, 4, and 8 h were monitored by Bacillus atrophaeus ATCC 9372 as a biological indicator (131) and by the GFP. Residual levels of EO, ECH, and EG were determined by gas chromatography (GC), and the residual dissipation was studied. Safe limits were reached right after the sterilization process for Oxygenator and after 204 h of aeration for Tubing. In the 2 h cycle, the GFP concentration decreased from 4.8 (+/- 3.2)% to 7.5 (+/- 2.5)%. For the 4 h cycle, the GFP concentration decreased from 17.4 (+/- 3.0)% to 21.5 (+/- 6.8)%, and in the 8 h cycle, it decreased from 22.5 (+/- 3.2)% to 23.9 (+/- 3.9)%. This finding showed the potentiality for GFP applications as an EO biosensor. (C) 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 9113: 626-630, 2009

Ultra-Fast Gradient LC Method for Omeprazole Analysis Using a Monolithic Column: Assay Development, Validation, and Application to the Quality Control of Omeprazole Enteric-Coated Pellets

A method was optimized for the analysis of omeprazole (OMZ) by ultra-high speed LC with diode array detection using a monolithic Chromolith Fast Gradient RP 18 endcapped column (50 x 2.0 mm id). The analyses were performed at 30 degrees C using a mobile phase consisting of 0.15% (v/v) trifluoroacetic acid (TFA) in water (solvent A) and 0.15% (v/v) TFA in acetonitrile (solvent B) under a linear gradient of 5 to 90% B in 1 min at a flow rate of 1.0 mL/min and detection at 220 nm. Under these conditions, OMZ retention time was approximately 0.74 min. Validation parameters, such as selectivity, linearity, precision, accuracy, and robustness, showed results within the acceptable criteria. The method developed was successfully applied to OMZ enteric-coated pellets, showing that this assay can be used in the pharmaceutical industry for routine QC analysis. Moreover, the analytical conditions established allow for the simultaneous analysis of OMZ metabolites, 5-hydroxyomeprazole and omeprazole sulfone, in the same run, showing that this method can be extended to other matrixes with adequate procedures for sample preparation.