Organic and Nitrogen Fertilization of Soil under ‘Syrah’ Grapevine: Effects on Soil Chemical Properties and Nitrate Concentration

ABSTRACT Viticulture is an activity of great social and economic importance in the lower-middle region of the São Francisco River valley in northeastern Brazil. In this region, the fertility of soils under vineyards is generally poor. To assess the effects of organic and nitrogen fertilization on chemical properties and nitrate concentrations in an Argissolo Vermelho-Amarelo (Typic Plinthustalf), a field experiment was carried out in Petrolina, Pernambuco, on Syrah grapevines. Treatments consisted of two rates of organic fertilizer (0 and 30 m3 ha-1) and five N rates (0, 10, 20, 40, and 80 kg ha-1), in a randomized block design arranged in split plots, with five replications. The organic fertilizer levels represented the main plots and the N levels, the subplots. The source of N was urea and the source of organic fertilizer was goat manure. Irrigation was applied through a drip system and N by fertigation. At the end of the third growing season, soil chemical properties were determined and nitrate concentration in the soil solution (extracted by porous cups) was determined. Organic fertilization increased organic matter, pH, EC, P, K, Ca, Mg, Mn, sum of bases, base saturation, and CEC, but decreased exchangeable Cu concentration in the soil by complexation of Cu in the organic matter. Organic fertilization raised the nitrate concentration in the 0.20-0.40 m soil layer, making it leachable. Nitrate concentration in the soil increased as N rates increased, up to more than 300 mg kg-1 in soil and nearly 800 mg L-1 in the soil solution, becoming prone to leaching losses.

Combining ability of twelve maize populations

Genetic progress depends on germplasm quality and breeding methods. Twelve maize populations and their crosses were evaluated to estimate combining ability and potential to be included as source populations in breeding programs. Plant height, point of insertion of the first ear, number of ears per plant, number of grains per ear, root and stalk lodging and grain yield were studied in two locations in Brazil, during the 1997/98 season. Genotype sum of squares was divided into general (GCA) and specific (SCA) combining ability. Results indicated the existence of genetic divergence for all traits analyzed, where additive effects were predominant. The high heterosis levels observed, mainly in Xanxerê, suggested the environmental influence on the manifestation of this genetic phenomenon. Populations revealed potential to be used in breeding programs; however, those more intensively submitted to selection could provide larger genetic progress, showing the importance of population improvement for the increment of the heterosis in maize.

Spatial variability of yield and other parameters associated with pear trees

In the last few years, precision agriculture has become commonly used with many crops, particularly cereals, and there is also interest in precision horticulture. Pear is a seasonal fruit and well appreciated by Brazilian people, although it is mostly imported. Brazilian farmers are nowadays trying to increase pear production. Thus, this research aimed at mapping the yield of pear trees in order to study the spatial variability of yield as well as its comparison with spatial variability of soil and plant attributes. The experimental field had 146 pear trees, variety 'Pêra d'água', distributed on a 1.24 ha. Four harvests were performed according to the fruit ripening and from each tree; only the ripe fruits were harvested. In each harvest, all the fruits were weighed and the total yield was obtained based on the sum of each harvest. The soil attributes analyzed were P, K, Ca, Mg, pH in CaCl2, C, Cu, Zn, Fe, Mn and base saturation, and the plant attributes were fruit length, diameter and yield. Yield had low correlation with soil and plant attributes. An index of spatial variability was suggested in this study and helped in classifying levels of spatial dependence of the various soil and plant attributes: very low (fruit length); low (P, fruit diameter), medium (Mg, pH, Cu, Zn, Fe), high (Ca, K, base saturation and yield), and very high (Mn and C).

Nitrogen fertilization by deep-bedding swine production and its effects on the properties of a Quartzarenic Neosol

The objective of this study was to evaluate the effects of the nitrogen fertilization in the form of swine deep bed in the properties of a quartz-sand neosol. The organic compound used was the deep bed made with rice hulls, from a commercial swine finishing system farm. Deep bed samples have been collected at various points in the installation in order to obtain a representative composite sample which has been fractionated in a 2.0 mm sieve and submitted to a 50-day maturation period. Then, agronomic value analyses were done. The experimental design was completely randomized. The treatments consisted of 0; 75; 150 and 300 mg dm-3 of N doses of deep bed as well as an additional treatment with ammonium sulfate at a 150 mg dm-3 of N. The experimental period in the greenhouse was 45 days, where the soil was cultivated with maize. After the experiment completion, further soil properties analyses were done. From the results, it was noted that the organic fertilization with deep bed provided a significant increase in the levels of potassium, in the sum of the bases, in the effective CEC, in the CEC at pH 7.0 and in the percentage of saturation.

Unexpected effects of pigeon-peas (Cajanus cajan) in the restoration of rupestrian fields

Several degraded areas can be found along the Highway MG-010 that crosses the Espinhaço Mountain Biosphere Reserve in the Brazilian state of Minas Gerais. Restoration by planting the legume Cajanus cajan was implemented in some of these areas. The present study compares plant species richness, diversity, abundance, equitability, similarity, and soil composition between restored and non-restored areas, in an attempt to evaluate the effectiveness of the use of C. cajan in the restoration process in the mountain environment. Each treatment (restored and non-restored) had four sampling areas, each with three 300 m² plots. We counted and identified every individual plant found within these plots. We also collected soil from the superficial layer (0-10 cm) of each sampling area in both treatments. The areas where C. cajan was planted revealed lower species richness, diversity, and plant abundance. The soil of these areas also contained higher levels of Phosphorus and Magnesium. Plant equitability and similarity between plots and other soil components (pH, Nitrogen, Aluminum, Calcium, Potassium, H+Al, sum of bases - SB, cation exchange capacity - CTC, base saturation - V%, aluminum saturation - M%) did not differ between the two treatments. Contrary to the expectations, soil enhancement in the quartzitic soil poor in nutrients in the rupestrian fields can facilitate the invasion by exotic plants, which are not adapted to the lack of nutrients. As it appears, the use of C. cajan in restoration projects represents a mistake and future restoration plans should avoid the use of exotic species, given that they may cause negative effects on the native plant community, as demonstrated here in the rupestrian fields.

Calculation of breed direct and maternal genetic fractions and breed specific direct and maternal heterozygosity for crossbreeding data

Teaching, research, and herd breeding applications may require calculation of breed additive contributions for direct and maternal genetic effects and fractions of heterozygosity associated with breed specific direct and maternal heterosis effects. These coefficients can be obtained from the first NB rows of a pseudo numerator relationship matrix where the first NB rows represent fractional contributions by breed to each animal or group representing a specific breed cross. The table begins with an NB x NB identity matrix representing pure breeds. Initial animals or representative crosses must be purebreds or two-breed crosses. Parents of initial purebreds are represented by the corresponding column and initial two-breed cross progeny by the two corresponding columns of the identity matrix. After that, usual rules are used to calculate the NB column entries corresponding to breeds for each animal. The NB entries are fractions of genes expected to be contributed by each of the pure breeds and correspond to the breed additive direct fractions. Entries in the column corresponding to the dam represent breed additive maternal fractions. Breed specific direct heterozygosity coefficients are entries of an NB x NB matrix formed by the outer product of the two NB by 1 columns associated with sire and dam of the animal. One minus sum of the diagonals represents total direct heterozygosity. Similarly, the NB x NB matrix formed by the outer product of columns associated with sire of dam and dam of dam contains breed specific maternal heterozygosity coefficients. These steps can be programmed to create covariates to merge with data. If X represents these coefficients for all unique breed crosses, then the reduced row echelon form function of MATLAB or SAS can be used on X to determine estimable functions of additive breed direct and maternal effects and breed specific direct and maternal heterosis effects

Persistent attenuation and enhancement of the earthworm main muscle contraction generator response induced by repeated stimulation of a peripheral neuron

Responses evoked in the earthworm, Amynthas hawayanus, main muscle contraction generator M-2 (postsynaptic mechanical-stimulus-sensitive) neuron by threshold mechanical stimuli in 2-s intertrial intervals (ITI) were used as the control or unconditioned responses (UR). Their attenuation induced by decreasing these intervals in non-associative conditioning and their enhancement induced by associating the unconditioned stimuli (US) to a train of short (0.1 s) hyperpolarizing electrical substitutive conditioning stimuli (SCS) in the Peri-Kästchen (PK) neuron were measured in four parameters, i.e., peak numbers (N) and amplitude ()averaged from 120 responses, sum of these amplitudes (SAMP) and the highest peak amplitude (V) over a period of 4 min. Persistent attenuation similar to habituation was induced by decreasing the control ITI to 0.5 s and 2.0 s in non-associative conditioning within less than 4 min. Dishabituation was induced by randomly pairing one of these habituated US to an electrical stimulus in the PK neuron. All four parameters of the UR were enhanced by forward (SCS-US), but not backward (US-SCS), association of the US with 25, 100 and 250-Hz trains of SCS with 40-ms interstimulus intervals (ISI) for 4 min and persisted for another 4 min after turning off the SCS. The enhancement of these parameters was proportional to the SCS frequencies in the train. No UR was evoked by the SCS when the US was turned off after 4 min of classical conditioning.

Influences of alpha-tocopherol on cholesterol metabolism and fatty streak development in apolipoprotein E-deficient mice fed an atherogenic diet

Although the role of oxidized lipoproteins is well known in atherogenesis, the role of vitamin E supplementation is still controversial. There is also little information about cholesterol metabolism (hepatic concentration and fecal excretion) in the new models of atherosclerosis. In the present study, we evaluated the effect of moderate vitamin E supplementation on cholesterol metabolism and atherogenesis in apolipoprotein E (apo E)-deficient mice. Apo E-deficient mice were fed an atherogenic diet containing 40 or 400 mg/kg of alpha-tocopherol acetate for 6 weeks. Total cholesterol in serum and liver and 3-OH-alpha-sterols in feces, and fecal excretion of bile acids were determined and histological analyses of aortic lesion were performed. A vitamin E-rich diet did not affect body weight, food intake or serum cholesterol. Serum and hepatic concentrations of cholesterol as well as sterol concentration in feces were similar in both groups. However, when compared to controls, the alpha-tocopherol-treated mice showed a reduction of about 60% in the atherosclerotic lesions when both the sum of lesion areas and the average of the largest lesion area were considered. These results demonstrate that supplementation of moderate doses of alpha-tocopherol was able to slow atherogenesis in apo E-deficient mice and to reduce atherogenic lipoproteins without modifying the hepatic pool or fecal excretion of cholesterol and bile acids.

Insulin secretion, insulin sensitivity, and hepatic insulin extraction in first-degree relatives of type 2 diabetic patients

To identify early metabolic abnormalities in type 2 diabetes mellitus, we measured insulin secretion, sensitivity to insulin, and hepatic insulin extraction in 48 healthy normal glucose-tolerant Brazilians, first-degree relatives of type 2 diabetic patients (FH+). Each individual was matched for sex, age, weight, and body fat distribution with a person without history of type 2 diabetes (FH-). Both groups were submitted to a hyperglycemic clamp procedure (180 mg/dl). Insulin release was evaluated in its two phases. The first was calculated as the sum of plasma insulin at 2.5, 5.0, 7.5, and 10.0 min after the beginning of glucose infusion, and the second as the mean plasma insulin level in the third hour of the clamp procedure. Insulin sensitivity index (ISI) was the mean glucose infusion rate in the third hour of the clamp experiment divided by the mean plasma insulin concentration during the same period of time. Hepatic insulin extraction was determined under fasting conditions and in the third hour of the clamp procedure as the ratio between C-peptide and plasma insulin levels. FH+ individuals did not differ from FH- individuals in terms of the following parameters [median (range)]: a) first-phase insulin secretion, 174 (116-221) vs 207 (108-277) µU/ml, b) second-phase insulin secretion, 64 (41-86) vs 53 (37-83) µU/ml, and c) ISI, 14.8 (9.0-20.8) vs 16.8 (9.0-27.0) mg kg-1 min-1/µU ml-1. Hepatic insulin extraction in FH+ subjects was similar to that of FH- ones at basal conditions (median, 0.27 vs 0.27 ng/µU) and during glucose infusion (0.15 vs 0.15 ng/µU). Normal glucose-tolerant Brazilian FH+ individuals well-matched with FH- ones did not show defects of insulin secretion, insulin sensitivity, or hepatic insulin extraction as tested by hyperglycemic clamp procedures.

Reliability and clinical utility of a Portuguese version of the Abnormal Involuntary Movements Scale (AIMS) for tardive dyskinesia in Brazilian patients

The objective of the present study was to evaluate the reliability and clinical utility of a Portuguese version of the Abnormal Involuntary Movements Scale (AIMS). Videotaped interviews with 16 psychiatric inpatients treated with antipsychotic drugs for at least 5 years were evaluated. Reliability was assessed by the intraclass correlation coefficient (ICC) between three raters, two with and one without clinical training in psychopathology. Clinical utility was assessed by the difference between the scores of patients with (N = 11) and without (N = 5) tardive dyskinesia (TD). Patients with TD exhibited a higher severity of global evaluation by the AIMS (sum of scores: 4.2 ± 0.9 vs 0.4 ± 0.2; score on item 8: 2.3 ± 0.3 vs 0.4 ± 0.2, TD vs controls). The ICC for the global evaluation was fair between the two skilled raters (0.58-0.62) and poor between these raters and the rater without clinical experience (0.05-0.29). Thus, we concluded that the Portuguese version of the AIMS shows an acceptable inter-rater reliability, but only between clinically skilled raters, and that it is clinically useful.

Abnormal subcellular distribution of GLUT4 protein in obese and insulin-treated diabetic female dogs

The GLUT4 transporter plays a key role in insulin-induced glucose uptake, which is impaired in insulin resistance. The objective of the present study was to investigate the tissue content and the subcellular distribution of GLUT4 protein in 4- to 12-year-old control, obese and insulin-treated diabetic mongrel female dogs (4 animals per group). The parametrial white adipose tissue was sampled and processed to obtain both plasma membrane and microsome subcellular fractions for GLUT4 analysis by Western blotting. There was no significant difference in glycemia and insulinemia between control and obese animals. Diabetic dogs showed hyperglycemia (369.9 ± 89.9 mg/dl). Compared to control, the plasma membrane GLUT4, reported per g tissue, was reduced by 55% (P < 0.01) in obese dogs, and increased by 30% (P < 0.05) in diabetic dogs, and the microsomal GLUT4 was increased by ~45% (P < 0.001) in both obese and diabetic animals. Considering the sum of GLUT4 measured in plasma membrane and microsome as total cellular GLUT4, percent GLUT4 present in plasma membrane was reduced by ~65% (P < 0.001) in obese compared to control and diabetic animals. Since insulin stimulates GLUT4 translocation to the plasma membrane, percent GLUT4 in plasma membrane was divided by the insulinemia at the time of tissue removal and was found to be reduced by 75% (P < 0.01) in obese compared to control dogs. We conclude that the insulin-stimulated translocation of GLUT4 to the cell surface is reduced in obese female dogs. This probably contributes to insulin resistance, which plays an important role in glucose homeostasis in dogs.

A routine electrocardiogram cannot be used to determine the size of myocardial infarction in the rat

Nine lead electrocardiograms of non-infarcted (N = 61) and infarcted (N = 71) female Wistar rats (200-250 g) were analyzed in order to distinguish left ventricle myocardial infarction (MI) larger than 40% (LMI) from MI smaller than 40% (SMI). MI larger than 40% clearly caused a deviation of ÂQRS and ÂT from normal values of 270-360 degrees to 90-270 degrees. Infarcted rats showed Q wave in D1 larger than 1 mm with 94% sensitivity and 100% specificity. The sum of QRS positivity in V1, V2 and V6 lower than 10 mm identified MI with 82% sensitivity and 100% specificity. The data showed that MI can be easily and reliably diagnosed by electrocardiogram in the rat. However, contradicting what is frequently believed, when specificity and sensitivity were analyzed focusing on MI size, none of these current electrocardiographic indices of MI size adequately discriminates LMI from SMI.

Comparison of etoricoxib and indomethacin for the treatment of experimental periodontitis in rats

We investigated the effect of etoricoxib, a selective cyclooxygenase-2 inhibitor, and indomethacin, a non-selective cyclooxygenase inhibitor, on experimental periodontitis, and compared their gastrointestinal side effects. A ligature was placed around the second upper left molars of female Wistar rats (160 to 200 g). Animals (6 per group) were treated daily with oral doses of 3 or 9 mg/kg etoricoxib, 5 mg/kg indomethacin, or 0.2 mL saline, starting 5 days after the induction of periodontitis, when bone resorption was detected, until the sacrifice on the 11th day. The weight and survival rate were monitored. Alveolar bone loss (ABL) was measured as the sum of distances between the cusp tips and the alveolar bone. The gastric mucosa was examined macroscopically and the periodontium and gastric and intestinal mucosa were examined by histopathology. The ongoing ABL was significantly inhibited (P < 0.05) by 3 and 9 mg/kg etoricoxib and by indomethacin: control = 4.08 ± 0.47 mm; etoricoxib (3 mg/kg) = 1.89 ± 0.26 mm; etoricoxib (9 mg/kg) = 1.02 ± 0.14 mm; indomethacin = 0.64 ± 0.15 mm. Histopathology of periodontium showed that etoricoxib and indomethacin reduced inflammatory cell infiltration, ABL, and cementum and collagen fiber destruction. Macroscopic and histopathological analysis of gastric and intestinal mucosa demonstrated that etoricoxib induces less damage than indomethacin. Animals that received indomethacin presented weight loss starting on the 7th day, and higher mortality rate (58.3%) compared to etoricoxib (0%). Treatment with etoricoxib, even starting when ABL is detected, reduces inflammation and cementum and bone resorption, with fewer gastrointestinal side effects.

Nutritional status and body composition after 6 months of patients switching from continuous ambulatorial peritoneal dialysis to automated peritoneal dialysis

Our objective was to determine if automated peritoneal dialysis (APD) leads to changes in nutritional parameters of patients treated by continuous ambulatory peritoneal dialysis (CAPD). Twenty-six patients (15 males; 50.5 ± 14.3 years) were evaluated during CAPD while training for APD and after 3 and 6 months of APD. Body fat was assessed by the sum of skinfold thickness and the other body compartments were assessed by bioelectrical impedance. During the 6-month follow-up, 12 patients gained more than 1 kg (GW group), 8 patients lost more than 1 kg (LW group), and 6 patients maintained body weight (MW group). Except for length on dialysis that was longer for the LW group compared with the GW group, no other differences were found between the groups at baseline. After 6 months on APD, the LW group had a reduction in body fat (24.5 ± 7.7 vs 22.1 ± 7.3 kg; P = 0.01), body cell mass (22.6 ± 6.2 vs 21.6 ± 5.8 kg, P = 0.02) and phase angle (5.4 ± 0.9 vs 5.1 ± 0.8 degrees, P = 0.004). In the GW group, body fat (25 ± 7.6 vs 27.2 ± 7.6 kg, P = 0.001) and body cell mass (20.1 ± 3.9 vs 20.8 ± 4.0 kg, P = 0.05) were increased. In the present study, different patterns of change in body composition were found. The length of previous dialysis treatment seems to be the most important factor in determining these nutritional modifications.

Characterization of the interdependency between residues that bind the substrate in a β-glycosidase

The manner by which effects of simultaneous mutations combine to change enzymatic activity is not easily predictable because these effects are not always additive in a linear manner. Hence, the characterization of the effects of simultaneous mutations of amino acid residues that bind the substrate can make a significant contribution to the understanding of the substrate specificity of enzymes. In the β-glycosidase from Spodoptera frugiperda (Sfβgly), both residues Q39 and E451 interact with the substrate and this is essential for defining substrate specificity. Double mutants of Sfβgly (A451E39, S451E39 and S451N39) were prepared by site-directed mutagenesis, expressed in bacteria and purified using affinity chromatography. These enzymes were characterized using p-nitrophenyl β-galactoside and p-nitrophenyl β-fucoside as substrates. The k cat/Km ratio for single and double mutants of Sfβgly containing site-directed mutations at positions Q39 and E451 was used to demonstrate that the effect on the free energy of ES‡ (enzyme-transition state complex) of the double mutations (∆∆G‡xy) is not the sum of the effects resulting from the single mutations (∆∆G‡x and ∆∆G‡y). This difference in ∆∆G‡ indicates that the effects of the single mutations partially overlap. Hence, this common effect counts only once in ∆∆G‡xy. Crystallographic data on β-glycosidases reveal the presence of a bidentate hydrogen bond involving residues Q39 and E451 and the same hydroxyl group of the substrate. Therefore, both thermodynamic and crystallographic data suggest that residues Q39 and E451 exert a mutual influence on their respective interactions with the substrate.