Assessment of effective doses from radon levels for tour guides at several galleries of Santana Cave, Southern Brazil, with CR-39 detectors: preliminary results

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeitos de baixas doses de cloprostenol via intramuscular ou submucosavulvar na indução do estro e taxas de prenhez em vacas Nelore

The present study aims to compare the effects of lower doses of cloprostenol intramuscular (IM) or into vulvar submucosa (IVS) on estrus induction and pregnancy rate in Nelore cows. A total of 100 cycling Nelore cows with body condition score (BCS 3.5) 1 to 5 scale (Radostitis; Blood, 1986) and 170 +/- 11 days postpartum. Females were randomly divided in 5 groups (N=20) G1 to G5 and treated with cloprostenol (Ciosin (R)) on day 0 (D0) and on day 11 (D11) if not detected in estrus. Cows were injected with 500 mu g IM (G1), 250 mu g IM (G2), 125 mu g IM (G3), 250 mu g IVS (G4) and 125 mu g IVS (G5). Estrus was observed twice a day and the females artificially inseminated 12 hours after heat detection. There was no statistical difference (P>0.80) between groups in the estrus induction (first injection to estrus interval): 16/20-96.00 hours (G1), 13/20-90.42 hours (G2), 10/20-84.45 hours (G3), 15/20-87.86 hours (G4), 12/20-81.25 hours (G5) and second injection (P>0.10): 4/20-67.50 hours (G1), 7/20-85.50 hours (G2), 10/20-57.00 hours (G3), 5/20-70.60 hours (G4), 8/20-60.00 hours (G5). There was no statistical difference (0.65(ns)) between groups in the pregnancy rates: 40% (G1), 45% (G2), 50% (G3), 40% (G4), 40% (G5). The results demonstrate that the treatments with lower doses of cloprostenol intramuscular or into vulvar submucosa may be used to induce heat with similar pregnancy rates in cycling Nelore cows with good body condition.

Épocas de aplicação de nitrogênio para híbridos de mamona no sistema plantio direto em safrinha

The castor bean cultivation has a high demand for nitrogen, in addition, the efficiency of nitrogen fertilization in most cases is low, so that this essential nutrient is provided at the appropriate time. The objective was to study the time nitrogen application in castor bean hybrids under no-till system in off-season. The experiment was carried out in an experimental area located in Botucatu, São Paulo State, Brazil, for two growing off-seasons (2006 and 2007). The experimental design was a randomized block in split plot design, with four replications. The plots were constituted by two castor bean hybrids (Lyra/Savana in 2006 and Lyra/Sara in 2007). Six combination of times out rates (0-0, 0-100, 100-0, 30-70, 70-30, 50-50 kg ha-1 of N) side dressing nitrogen fertilization constituted the subplots. The N source used was ammonium nitrate, applied 20 days after emergence and 40 days after emergence. Measurements were carried out: dry matter production of shoots, nitrate and ammonium leaf, leaf analysis, yield components and nitrogen factor utilization. The highest grain yield was obtained to the hybrid Lyra with nitrogen fertilization. In 2006 the highest nitrogen utilization factor to the hybrid Lyra was obtained with the form 70-30 and in the 2007 with 50-50.

Parâmetros bioquímicos sanguíneos, balanço de nitrogênio e metabolizabilidade da energia bruta em suínos alimentados com dietas contendo diferentes balanços eletrolíticos

The aim of this study was to evaluate different dietary electrolyte balance (DEB) on the blood biochemical parameters, nitrogen balances and crude metabolizable energy of swine in the initial phase. Sixteen barrows were used, averaging 27.95 kg of initial weight, allotted individually in metabolic cages in a randomized blocks design with four treatments (DEB of 160, 208, 257 and 305 mEq/kg) and 4 replicates. The blood biochemical parameters analyzed were chloride, potassium, sodium and urea in blood. Urine pH was also evaluated, and the parameters evaluated in nitrogen (N) balance were N intake, fecal N, N excreted in urine, absorbed N, N retention, retained N/absorbed N and total excretion of N. The gross energy digestibility and metabolizibility coefficients were determined, and the respectives values of digestible and metabolizable energy. The values of urinary pH increased (P < 0.01) linearly with increasing levels of DEB, ranging from 6.90 to 8.03. The results for chloride, potassium and nitrogen balances of variables and gross energy were similar (P > 0.05) between the evaluated DEB. A linear increase (P < 0.01) was also observed for sodium concentrations in blood serum due to the increase of DEB, with values of 2.91, 3.03, 3.27 and 3.18 g/l, respectively for the different treatments. Urea levels in blood serum increased linearly (P < 0.01), with values of 26.21, 28.64, 34.32 and 32.89 mg/dl. It was concluded that increasing the dietary electrolyte balance, from 160 to 305 mEq/kg resulted in higher concentrations of urea and sodium in blood serum, and higher pH values in the urine of swine in the initial phase.

Doses and sources of nitrogen fertilizer and their effects on soil chemical properties and forage yield of Brachiaria brizantha cv. Xaraes

Forage plants, particularly the Brachiaria genus, are the main source of nutrients for cattle and are at times the only feed offered. The concentration of elements in the plant is related to the soil, fertilization, climate, season, variety, and cultural practices. An experiment on dystrophic Red-Yellow Latosol soil in Aracatuba, São Paulo was performed to evaluate the effects of the doses and sources of nitrogen fertilizers on the chemical properties of the soil and the dry matter yield of the grass Brachiaria brizantha cv. Xaraes. A randomized block design was employed involving three replicates in a 3 x 3 factorial, with three doses (100, 200 and 400 kg ha(-1) year(-1)) and three sources (Ajifer (R) L40, ammonium sulfate and urea) of nitrogen and a control treatment without nitrogen (zero). The greatest effects on the chemical properties of the soil as a function of nitrogen fertilization in the Xaraes grass were observed in the topsoil. The use of Ajifer (R) L40 and ammonium sulfate as sources of nitrogen had similar effects, with an increase in the sulfur content and a reduction in the soil pH at the superficial layer. The use of the fertilizers Ajifer (R) L40, ammonium sulfate and urea did not affect the micronutrient contents, except for Fe and Mn, and did not alter the sodium concentration or electrical conductivity of the soil. The dry matter yield of Xaraes grass was similar for all three nitrogen sources.

Modificacoes na ação mecânica do coração isolado de cobaia por doses de propafenon capazes de alterar o eletrocardiograma

Inotropic effects of Propafenon were studied in isovolumic isolated guinea pig hearts submitted to infusion of the drug during 10 minutes. The dosages utilized caused: bradycardia, depression of AV nodal conduction and QRS widening. Simultaneously there was: decrease of the developed pressure (DP) and of the rate of rise of pressure (dp/dt), and elongation of the time of peak pressure. Since there was no clear relation between the heart rate and the inotropic indices (PD and dp/dt), it could be supposed that the depressor effect was not due to impairment of the chronotropism only. After the infusion of Propafenon, the chronotropic effect disapeared after 15 min, while the inotropic state presented a less satisfatory recuperation. The coronary output accompanied the myocardial metabolic needs, that is to say, there was a fall during the period of depressed cardiac function and a later tendency to increase during recovery.

Effects of cumulative doses of vinasse on soil microorganisms in cerrado

Counts of colony forming units of actinomycetes, bacteria and filamentous fungi were determined in cerrado soil treated with vinasse (processed sugar cane effluent) for 5 yr, using doses of 20 l m-2a-1 and 50 l m-2a-1. A temporary increase in the counts of actinomycetes and bacteria for some months after the addition of vinasse was observed. An increased number of fungi was detected throughout the experiment together with qualitative changes in the population. The most abundant fungi in cerrado soil not treated with vinasse (control soil) were Chaetomium, yeasts, Mucor, Penicillium and Trichoderma, while in vinasse treated soils, the same genera adding Verticillium, with the exception of yeasts, were the most common fungi. -Author

Niobium filtration of conventional and high-frequency x-ray generator beams for intraoral radiography. Effects on absorbed doses, image density and contrast, and photon spectra

We have studied the effects of niobium beam filtration on absorbed doses, on image density and contrast, and on photon spectra with conventional and high-frequency dental x-ray generators. Added niobium reduced entry and superficial absorbed doses in periapical radiography by 9% to 40% with film and digital image receptors, decreased the radiation necessary to produce a given image density on E-speed film and reduced image contrast on D- and E-speed films. As shown by increased half-value layers for aluminum, titanium, and copper and by pulse-height analyses of beam spectra, niobium increased average beam energy by 6% to 19%. Despite the benefits of adding niobium on patient dose reduction and on narrowing the beams' energy spectra, the beam can be overhardened. Adding niobium, therefore, strikes the best balance between radiation dose reduction and beam attenuation, with its risks of increased exposure times, motion blur, and diminished image contrast, when it is used at modest thicknesses (30 μm) and at lower kVp (70) settings. © 1995 Mosby-Year Book, Inc.

Efeitos nutricionais da substituição parcial do farelo de soja por uréia, em dieta de ovinos. Comparação da digestibilidade aparente e balanço de nitrogênio com a cinética do metabolismo da 15N-glicina

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Degradabilidade ruminai da fibra em detergente neutro e do nitrogênio insolúvel em detergente neutro da silagem de milho e do farelo de soja, em bovinos da raça nelore

The nylon bag in situ degradation thecnique was employed to study the ruminai degradability of the neutral detergent fiber and neutral detergent insoluble nitrogen of the corn silage and soybean meal in four rumen fistulated Nellore steers, averaging 36 months of age and 520 kg of liveweight. A randomized completelcs block experimental design was used, where the animals constituted the blocks. It was used diets with two levels of concentrate: 20 and 40%.The forage used in the diets was corn silage, and the concentrate ingredients were: soybean meal, cottonseed meal, corn grain and sorghum grain. The NIDN degradation rate of the corn silage and the soybean meal showed a decrease of 32,1% and of 46,0 % as a function of the higher concentrate level of the diet, but the effective and potential degradability of this fraction were not affected. Concerning to the NDF, the soluble fraction, potentially degradable and undegrable , were not affected by the increase on the diet concentrate level, but for the corn silage, there were 21,8% of reduction on the effective degradability of NDF. The use of lag time promoted higher degradability values for the studied fraction. The obtained values for some evaluated parameters, different from that assumed by CNCPS, showed the necessity of more data about brazilian used feeds, for model adjustments.

Efeitos de diferentes doses de tenoxicam sobre a medula espinhal e as meninges. Estudo experimental em caes

Background and Objectives. The analgesic actions of nonsteroidal anti-inflammatory drugs (NSAID) result from the inhibition of the peripheral synthesis of prostaglandins. In spite of the emphasis on the peripheral action, several studies have shown the potential central action of such drugs. In rats, NSAID doses insufficient to block pain when systemically administered were effective when intrathecally injected. This effect could be mediated by interaction with descending serotoninergic ways together with neurotransmission modulation of glycine or N-methyl-D-aspartate receptors. Our goal was to study the effect of different tenoxican doses in the histology of dogs spinal cord and meninges. Methods. Thirty two dogs (7 to 17 kg) were randomly distributed in four groups: G1 - Control with distilled water (DW); G2 - 2 mg tenoxican diluted in DW; G3 - 4 mg tenoxican diluted in DW; G4 - 10 mg tenoxican diluted in DW in a constant volume of 1 ml. Anesthesia was induced with etomidate and fentanyl and dural puncture was performed with a 25G spinal needle in interspace L6-7. Animals were observed for 72 hours and subsequently euthanized by electrocution. Lumbar and sacral spinal cord segments were removed for further histologic examination. Results. All animals were clinically normal during the observation period and there has been no histologic alteration of the nervous system and meninges. Conclusions. In our experimental model intrathecal tenoxican doses up to 10 mg have not triggered nervous tissue or meningeal injuries in dogs.

The effect of non-antihypertensive doses of angiotensin converting enzyme inhibitor on myocardial necrosis and hypertrophy in young rats with renovascular hypertension

In renovascular hypertensive rats, low doses of angiotensin converting enzyme (ACE) inhibitors have been found to prevent myocardial hypertrophy independent of blood pressure level. This finding would suggest humoral rather than mechanical control of myocyte growth. The aim of this study was to examine the effect of nonantihypertensive doses of ACE inhibitor on myocardial hypertrophy and necrosis in hypertensive rats. Renovascular hypertension (RHT) was induced in four-week-old Wistar rats. Twenty-eight animals were treated for four weeks with three doses of ramipril (0.01, 0.1 or 1.0 mg/kg/day, which are unable to lower blood pressure. Fourteen animals were not treated (RHT group). A sham operated, age/sex-matched group was used as control (n=10). Myocardial histology was analysed in 3 μm thick sections of the ventricle stained with either haematoxylin-eosin, reticulin silver stain or Masson's trichrome. There was a significant correlation between systolic blood pressure and left ventricular to body weight ratio in both sets of animals: untreated plus controls and ramipril-treated rats. ACE inhibition prevented myocyte and perivascular necrosis and fibrosis in a dose-dependent manner. We conclude that myocardial hypertrophy in rats with renovascular hypertension is directly related to arterial pressure, and that this relationship is not affected by nonantihypertensive doses of ACE inhibitor. Myocardial necrosis/fibrosis and coronary artery damage induced by angiotensin II are prevented by ACE inhibitor in a dose-dependent manner, despite the presence of arterial hypertension.

Experimental control of the effect of extra doses of juvenile hormone on bee development: The case of the wax glands of Apis mellifera (Hymenoptera: Apidae)

Experiments on the effect of topical application of the synthetic juvenile hormone (JH-III) and of the solvent used to dissolve the hormone on the development of the wax glands of workers of Apis mellifera, were made. The results show that it was impossible to determine the effect of the juvenile hormone (JH) apart from its solvent (acetone), which also alters the developmental pattern of the gland. Most of the experiments reported in scientific literature do not consider the effect of the solvent, analyzing the results by only comparing the treatment with the hormone plus solvent to a control without any treatment. The data presented suggests that this kind of procedure compromises the evaluation of the real JH effect.