Yield and nitrogen uptake of peanuts as affected by lime, cobalt, and molybdenum

Peanut response to lime has been associated to calcium (Ca) nutrition, but a higher nitrogen (N) uptake has been observed in limed plots probably due to an increase in molybdenum (Mo) availability. A two-year experiment was conducted to study the effects of Mo, cobalt (Co), and liming on peanut yields and N nutrition. Peanut seeds were treated with Mo and/or Co and grown in soil with base saturation about 13, 41, 57, and 71%. There was no effect of seed treatment with Co on peanut yields or N nutrition. Liming and Mo application increased N contents in the leaves. Nitrogen uptake was increased by Mo and liming in cv. Tatu and only by liming in cv. Tupa. Manganese (Mn) contents in the leaves were decreased by liming. The higher yields were observed when the Ca/Mn ratio in the leaves was above 25. In acid soils, low availability of Mo and Mn toxicity can impair N acquisition by peanut plants and decrease grain yields.

Thiabendazole uptake and persistence in lemons following postharvest dips at 50 degrees C

Thiabendazole (TBZ) uptake and degradation rate in lemon fruits, following prestorage dipping at 50 degrees C in mixtures containing different amounts of fungicide, was compared with those measured after treatment at standard room temperature. TBZ residues were strictly dependent upon the amount of fungicide. Following 1,200 ppm TBZ dipping at 20 degrees C residue uptake in fruit was the same that would have been accumulated with ca. 150 ppm fungicide at 50 degrees C, a value that can be calculated due to the linear relationship between the residue in fruit after treatment and fungicide concentration TBZ residues showed great persistence during fruit storage: after 13 weeks at 8 degrees C and 1 week at 20 degrees C residues in fruit averaged ca. 70% of their initial values. In this study it was shown that it is possible to employ remarkably low amounts of TBZ (ca. 150 mg kg(-1)), when applied in combination with water at 50 degrees C, and keep the same residues of fruit treated at room temperature with high amounts of TBZ (1,200 mg kg(-1)).

CIRCADIAN OSCILLATORY PATTERNS OF OXYGEN-UPTAKE IN INDIVIDUAL WORKERS OF THE ANT CAMPONOTUS-RUFIPES

Respiratory rates of individual workers of Camponotus rufipes Fabricius (Hymenoptera: Formicidae) were measured at 25-degrees-C and LD 12:12 h (lights on 06.00 hours), DL 12:12 h (lights on 18.00 hours), LL (850 lux) and DD (red light, 20-30 lux), using the micro-Warburg technique. Worker ants were collected from natural nest during the winter of 1987 in a woodland park in the region of Rio Claro, São Paulo, Brazil. The respiration of ants showed a circadian rhythm with acrophase ranging from 20 h 41 min to 01 h 18 min and from 10 h 32 min to 12 h 22 min at LD and DD, respectively. In constant darkness the rhythmometric variables were similar to those presented by ants kept at LD 12:12 h. Under constant light no circadian rhythm in the respiration rates was found. A reduction in the amplitude was observed, indicating an inhibitory effect of this light regime on the respiration process.

RESPONSE TO TEMPERATURE IN THE OXYGEN-UPTAKE OF AWAKE AND DORMANT FROGS (AMPHIBIA, LEPTODACTYLIDAE)

In southeastern Brazil the leptodactylid frogs Leptodactylus fuscus and Physalaemus fuscomaculatus enter dormancy during the dry season. Oxygen uptake was measured in awake and dormant groups of both species in a temperature range at which these frogs are usually exposed throughout the year. Oxygen uptake was lower for dormant groups at high temperature, and a lack of response to temperature was reported between 20 - 25 C in the dormant group of both species. This temperature-intensitive range can be considered an adaptive feature to save fat reserves during dormancy.

Effects of aerobic endurance training status and specificity on oxygen uptake kinetics during maximal exercise

The main purpose of this study was to analyze the effects of exercise mode, training status and specificity on the oxygen uptake ((V)over dot O-2) kinetics during maximal exercise performed in treadmill running and cycle ergometry. Seven runners (R), nine cyclists (C), nine triathletes (T) and eleven untrained subjects (U), performed the following tests on different days on a motorized treadmill and on a cycle ergometer: (1) incremental tests in order to determine the maximal oxygen uptake ((V)over dot O-2max) and the intensity associated with the achievement of (V)over dot O-2max (I(V)over dot O-2max); and (2) constant work-rate running and cycling exercises to exhaustion at I(V)over dot O-2max to determine the effective time constant of the (V)over dot O-2 response (tau(V)over dot O-2). Values for (V)over dotO(2max) obtained on the treadmill and cycle ergometer [R=68.8 (6.3) and 62.0 (5.0); C=60.5 (8.0) and 67.6 (7.6); T=64.5 (4.8) and 61.0 (4.1); U=43.5 (7.0) and 36.7 (5.6); respectively] were higher for the group with specific training in the modality. The U group showed the lowest values for VO2max, regardless of exercise mode. Differences in tau(V)over dot O-2 (seconds) were found only for the U group in relation to the trained groups [R=31.6 (10.5) and 40.9 (13.6); C=28.5 (5.8) and 32.7 (5.7); T=32.5 (5.6) and 40.7 (7.5); U=52.7 (8.5) and 62.2 (15.3); for the treadmill and cycle ergometer, respectively]; no effects of exercise mode were found in any of the groups. It is concluded that tauVO(2) during the exercise performed at I(V)over dot O-2max is dependent on the training status, but not dependent on the exercise mode and specificity of training. Moreover, the transfer of the training effects on tau(V)over dotO(2) between both exercise modes may be higher compared with (V)over dot O-2max.

REEVALUATION OF CHLORIDES REGULATION OF HEMOGLOBIN OXYGEN-UPTAKE - THE NEGLECTED CONTRIBUTION OF PROTEIN HYDRATION IN ALLOSTERISM

We have measured hemoglobin oxygen uptake vs. The partial pressure of oxygen, with independently controlled activities of chloride and water. This control is effected by combining different concentrations of NaCl and sucrose in the bathing solution to achieve: (i) water activities were varied and CI- activity was fixed, (ii) both water and CI- activities were varied with a traditional NaCI titration, or (iii) CI- activities were varied and water activity was fixed by adding compensating sucrose. Within this analysis, the CI--regulated loading of four oxygens can be described by the reaction Hb.CI- + 4 O-2 + 65 H2O reversible arrow Hb.4O(2).65H(2)O + CI-. The dissociation of a neatly integral chloride, rather than the nonintegral 1.6 chlorides inferred earlier from simple salt titration, demonstrates the need to recognize the potentially large contribution from changes in water activity when titrating weakly binding solutes. The single-chloride result might simplify structural considerations of the action of CI- in hemoglobin regulation.

Kinetics of zinc uptake and anatomy of roots and leaves of coffee trees as affected by zinc nutrition

Zinc (Zn) uptake kinetics and root and leaf anatomy were studied in coffee trees grown in nutrient solutions with or without Zn. Leaves and roots were sampled and cuts were made in the medium part of the leaves and in root tips and observed under an optical microscope. Plants grown without Zn showed an increase in root and in root stele diameter. There was also an increase in epidermis thickness and in the cross-sectional area of the cortex and stele due to Zn deficiency, but the diameter of xylem vessels was decreased. An increase in root cortex and stele diameter provided for an increased surface for nutrient uptake. Accordingly, C(min) was decreased from 13.8 to 3.4 mu mol L(-1) and V(max) increased from 0.50 to 2.1 mu mol cm(-2) h(-1) .

Characterization of PLGA microparticles as a drug carrier for 3-ethoxycarbonyl-2H-benzofuro[3,2-f]-1-benzopyran-2-one. Ultrastructural study of cellular uptake and intracellular distribution

Here we describe the application of microparticles (MPs) for the delivery and release of the drug a benzopsoralen. We also evaluated the intracellular distribution and cellular uptake of the drug by using an encapsulation technique for therapeutic optimization. MPs containing the compound 3-ethoxycarbonyl-2H-benzofuro[3,2-f]-1-benzopyran-2-one (psoralen A) were prepared by the solvent evaporation technique, and parameters such as particle size, drug encapsulation efficiency, effect of the encapsulation process on the drug's photochemistry, zeta potential, external morphology, and < i > in vitro release behavior were evaluated. The intracellular distribution of MPs as well as their uptake by tissues were monitored. Size distribution studies using dynamic ligh scattering and scanning electron microscopy revealed that the MPs are spherical in shape with a diameter of 1.4 mu m. They present low tendency toward aggregation, as confirmed by their zeta potential (+10.6 mV). The loading efficiency obtained was 75%. As a consequence of the extremely low diffusivity of the drug in aqueous medium, the drug release profile of the MPs in saline phosphate buffer (pH 7.4) was much slower than that obtained in the biological environment. Among the population of peritoneal phagocytic cells, only macrophages were able to phagocytose poly-d,l-lactic-co-glycolic acid (PLGA) MP. The use of psoralen A in association with ultraviolet light (360 nm) revealed morphological characteristics of cell damage such as cytoplasmic vesiculation, mitochondria condensation, and swelling of both the granular endoplasmatic reticulum and the nuclear membrane. These results indicate that PLGA MP could be a promising delivery system for psoralen in connection with ultraviolet irradiation therapy (PUVA).

Effects of Exercise Mode on the Oxygen Uptake Kinetic Response to Severe-Intensity Exercise in Prepubertal Children

The objective of this study was to verify the effect of the exercise mode on slow component of VO(2) (VO(2)SC) in children aged 11-12 years during severe-intensity exercise. After determination of the lactate threshold (LT) and peak VO(2) (VO(2)peak) in both cycling (CE) and running exercise (TR), fourteen active boys completed a series of "square-wave" transitions of 6-min duration at 75%Delta [75%Delta = LT + 0.75 X (VO(2)peak-LT)l to determine the VO(2) kinetics. The VO(2)SC was significantly higher in CE (180.5 +/- 155.8 ml . min(-1)) than in TR (113.0 +/- 84.2 ml . min(-1)). We can conclude that, although a VO(2)SC does indeed develop during TR in children, its magnitude is considerably lower than in CE during severe-intensity exercise.

On-line redox speciation analysis of antimony using L-proline immobilized on controlled pore glass and hydride generation inductively coupled plasma optical emission spectrometry for detection

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

Skin water uptake and renal function in the toad

1. 1. Water balance in the toad Bufo marinus ictericus was studied by evaluating cutaneous water uptake and renal excretion. 2. 2. The permeability of the skin to water was 78 ± 6 nl min -1 cm -2 atm -1 in 60 toads anaesthetized by chloralose and preincubated in water for 3 hr. Injection of Ringer's solution did not reduce the water uptake by the skin, while hemorrhage, or injection of vasopressin, or oxytocin approximately doubled the rates of water transport. In vivo values of skin water permeability were similar to those observed in vitro. 3. 3. The renal parameters of the water balance were significantly reduced by hemorrhage and by injection of vasopressin. Injection of Ringer's solution promoted a significant increase of the urinary flow and osmolar clearance. 4. 4. It is suggested that the fight against water deprivation could proceed initially by the triggering of the urinary mechanisms of water retention, while the increase of the skin water permeability would occur in a later stage. © 1981.

Oxygen uptake of active and aestivating earthworm Glosso scolex pa ulistus (Oligochaeta, Glossoscolecidae)

1. 1. The onset of or reactivation from aestivation in the earthworm Glossoscolex paulistus were dependent upon soil moisture. No evidence of temperature effect in the process was found either in field or laboratory data. 2. 2. Oxygen uptake measured in active and aestivating groups revealed remarkable reduction for aestivating earthworms at various temperatures studied. 3. 3. No evidences of temperature compensation in oxygen uptake was found in both groups of earthworms, indicating that reduction in oxygen uptake is the only adaptation for the aestivating G. paulistus. © 1985.