Efeitos da nutrição mineral na competição inter e intraespecífica de Eucalyptus grandis e brachiaria decumbens: 1- crescimento

The present work was conducted with the objective to study the effects of mineral nutrition on Eucalyptus grandis and Brachiaria decumbens (#BRADC) growth, when submitted to inter- and intra-specific competition. The treatments consisted of two plants of Eucalypts/pot, two plants of BRADC/pot, and one plant of each species/pot. The plants were nourished with the Hoagland e Arnon (1950) complete solution; with no K, P or N; or only with either N, P or K. Sixty days after growing side by side, no effect of the inter- and intra-specific competition on eucalypts plant high, branch number and leaf dry mass was observed. When mineral nutrition did not limit plant growth (complete solution or solution with no K), intra-specific competition reduced on average, 23% of eucalypts root length, leaf area, and stem and root dry mass, and inter-specific competition reduced, on average, 75% of BRADC dry mass. When mineral nutrition became a limiting factor, no plant competition effect on the parameters studied was detected.

Efeito da densidade de plantas de Bracharia decumbens Stapf sobre o crescimento inicial de mudas de Eucalyptus grandis W. Hill ex Maiden

In order to verify the effect of Brachiaria decumbens plant density on the initial growth of Eucalyptus grandis plants, one assay was conducted under semi-controlled conditions of soil fertility and humidity. Dark red Latossol, collected from the arable layer, was used as substrate in 50 liters amianthus cement boxes. One seedling of Eucalyptus was planted in each box. Fifteen days later, seedlings of B. decumbens were transplanted on the same box. The treatments consisted of 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 60, 80, 100, and 120 plants of B. decumbens. The experimental design was the complete randomized design, with 15 treatments and four replicates. The Eucalyptus plants that lived with B. decumbens were evaluated for stem diameter, plant high, leaf area, and dry weight of stem, branches and leaves. B. decumbens plants were evaluated for dry weight of aerial parts. B. decumbens, at the density level of four plants per m 2 and over, reduced of the initial growth of the Eucalyptus plants. B. decumbens reduced on average 27.78% stem diameter, 18.47% plant high, 70.56% leaf number, 63.26% leaf area, and 55.22%, 77.29% and 55.30% of stem, branch and leaf dry weight, respectively. Plant high was not a good parameter to evaluate the B. decumbens interference.

Estudo de modelo alternativo para estimação de componentes de (co)variância e predição de valores genéticos de características de crescimento em bovinos da raça Nelore

The objectives of this study were to estimate genetic parameters for non-standardized weights at nursing (PR120), at weaning (PR240), at yearling (PR365) and at post yearling (PR550), and to predict EPD's (expected progeny differences) for these traits using records from 29,769 Nellores. Covariance components and genetic parameters were estimated by mixed-model methodology, REML, using an animal model. Models for PR120, PR240, PR365 and PR455 included the random direct and maternal animal effects, the dam permanent environmental effect and the error. Fixed effects were contemporary group (CG) and age of cow at parturition (CIVP) and the covariate age of the calf at measuring. Two additional models for PR365, PR455 and PR550 analyses were used: the first included CG and CIVP, animal and maternal direct effect, residual and age of the calf (as covariate), and the second included CG and CIVP (as fixed effects), animal direct effect, residual and age of calf at measuring. Observed means±standard deviations were: 127±25kg (PR120); 191±34kg (PR240); 225±42kg (PR365); 266±51kg (PR455) and 310±56kg (PR550). From single-trait analyses, direct and maternal heritabilities for PR120, PR240, PR365 and PR455 were, respectively, .23 and .08; .19 and .10; .24 and .04; .30 and .04. Direct heritabilities were .39; .44 and .43, respectively, for PR365, PR455 and PR550. In the model without permanent effect, direct and maternal heritabilities for PR365, PR455 and PR550 were .25 and .08; .32 and .07; .38 and .03, respectively. When the estimates for standardized traits at the same period were compared, no differences in magnitude were found. Rank correlation had important changes when standardized and non-standardized traits were compared.

Períodos de interferência de erva-quente (Spermacoce atifolia) no crescimento inicial de eucalipto (Eucalyptus grandis)

The buttonweed (Spermacoce latifolia) is becoming a plant among the most current infesting eucalypts plantation in State of São Paulo due to the continual use of same herbicides and control methods. Owing this, this work aimed to evaluate the effects of periods of company and control of S. Iatifolia on the initial growth of Eucalyptus grandis, planted in winter and summer. Only one seedling of Eucalyptus was planted in amianthus cement box and submitted for crescent periods of company and control of S. Iatifolia (0, 20, 60 and 80 days in competition or not). The densities of plants of S. Iatifolia were 4 and 16 plants per m 2 (under winner and summer conditions). The experimental period was 100 days after the planting (DAP). The experimental design for both experiments was the completely randomized blocks (CRB) with ten treatments and four replicates. The results of plant high, stem diameter, dries weights and leaf area showed that the before interference period (BIP), whole period of prevention for interference (WPPI) and critical period of prevention for interference (CPPI) were 40, 60, and 60 DAR, respectively, under winner conditions. Under summer conditions, the WPPI and CPPI were 20, 80 and 20 to 80 DAR.

Influência do fotoperíodo no crescimento e sobrevivência de póslarvas de piracanjuba Brycon orbignyanus (Valenciennes, 1849) (Osteichthyes, Characidae)

This paper aims at studying the influence of photoperiod on the cultivation of Brycon orbignyanus (Valenciennes, 1849) (Osteichthyes, Characidae) post-larvae submitted to four treatments: 0L-24D (L=Light; D=Dark), 10 - L14D, 14L - 10D and 24L-0D, with 3 repetitions. Post-larvae measuring 7.8±0.7mm and weighting 3.5±0.8mg were distributed in 12 aquariums (10L), stocked with 12 post-larvae per aquarium. Fishes were fed daily with Artemia sp. nanplii, in 10 days experiment. A positive relationship between the survival rate (88.9±9.7%) observed in the treatment with 24 hours of luminosity, and the lowest (58.3±8.3%), in the treatment with 24 hours of darkness. No difference was showed (P>0.05) in the mean length and weight of the post-larvae, although there was greater heterogeneity among the post-larvae cultivated at the longer darkness period.

Abundância natural do isótopo estável de carbono (13C) de alguns itens alimentares e sua contribuição no crescimento de juvenis de pintado, Pseudoplatystoma corruscans (Agassiz, 1829) (Osteichthyes, Pimelodidae)

The aim of this study is to determine the natural abundance of carbon stable isotope (13C) of some food components and determine its contribution to the pintado juvenile growth, in laboratory conditions. 150 fishes were used with average weight of 1.39 g, and stocked in two net ponds with 125L each, during 60 days. Every 10 days a water sample was collected to analyse phytoplakton and zooplankton. Clacocera was dominant in the analysis of the stomach contents, following Chironomidae and Copepoda. A fish sample was collected in the beginning, and at the end of the experiment to analyses the isotopic signal. An average value of -20.94; -15.36 and -18.81 δ13C%o was obtained for phytoplankton, Cladocera and Chironomidae, respectively. Cladocera was the main carbon source and contribution with carbon average 89.24% in feeding this species, while the Chironomid contribution was 10.76%. The δ13C was effective as carbon tracer in food chain, because the consumer reflects its diet isotopicly.

Efeito do alumínio no crescimento de brotações de Eucalyptus grandis x E. urophylla cultivadas in vitro

The aim of this work was to evaluate the effects of aluminum on the growth of Eucalyptus shoots cultivated in vitro through nutrient and total soluble protein content. The trial had a totally randomized design with four treatments and four replicates. The treatments were: 0.0; 0.25; 0.5 and 1.0 mM of AlCl 3.6H 2O. Shoots without roots of a Eucalyptus grandis x E urophylla clone were used for the in vitro culture. Evaluations were made on the 4th, 8th, 12th, 16th, 20th, 24th and 28th day of culture. The Al addition to the culture media reduced mainly Ca, P and K availability and absorptions by the shoots. The cellular metabolism was affected, conducted to morphological alterations in shoots (browning, mass calluses formation and shoots not friable), dry matter increased and a decreased in total protein soluble.

Efeito da densidade de plantas de Panicum maximum Jacq. sobre o crescimento inicial de Eucalyptus grandis W.Hill ex Maiden

In order to verify the effect of Panicum maximum plant density on the initial growth of Eucalyptus grandis plants, one assay was conducted under semi-controlled conditions of soil fertility and humidity. Dark red Latossol, collected from the arable layer, was used as substrate in 50 liters amianthus cement boxes. One seedling of Eucalyptus was planted in each box. Fifteen days later, seedlings of P. maximum were transplanted on the same box. The treatments consisted of 0, 4, 8, 12, 16 and 20 plants of P. maximum per m 2. The experimental design was the complete randomized design, with six treatments and eight replicates for P. maximum. One hundred and ten and 190 days after transplanting, Eucalyptus plants grown among P. maximum showed an average reduction of 30.80 and 46.55% stem diameter, 25.10 and 22.50 plant high, 40.18 and 31.29% stem dry weight, 61.32 and 54.06% branch dry weight, 53.72 and 51.82% root dry weight, 44.62 and 38.50% leaf dry weight, 22.51 and 23.16 branch number, 20.72 and 19.97% leaf number, and 33.88 and 17.05% leaf area, respectively.

Faixas de controle de plantas daninhas e seus reflexos no crescimento de plantas de eucalipto

Two field trial were conducted in Eucalyptus grandis W. Hill ex Maiden x Eucalyptus urophylla S.T. Blake crops at Três Lagoas, Mato Grosso do Sul State and Brotas, São Paulo State, Brazil, to evaluate the effects of weed control in strip of different width on the Eucalyptus plant growth. The experiments consisted of two groups treatments: group 1 - with constant width control strips being kept during the first 12 months, i.e., at 0, 25, 50, 100, 125 and 150cm on each side of the Eucalyptus row and, group 2: with increasing width control strips being adopted along the experimental period, i.e., at 25 to 150, 25-50-150, 50 to 150, 50-125-150, 100-125-150, 100 tot 150 and 125 to 150 cm on each side of the Eucalyptus row during the first 12 months. At 49 moths after planting it was verified that the Eucalyptus plants that had grown both in the constant and increasing width control strips, equal to or higher than 100 and 50 cm, respectively, showed higher steam diameter, plant height, volume and annual increment average of wood. These results led to the conclusion that the minimum control strip width should be 100 cm on each side of the Eucalyptus row in order to keep the crop free of weed interference.

Fator de crescimento derivado de plaquetas humanas obtido por uma metodologia rápida e de baixo custo

Human platelet-derived growth factor (PDGF) was purified from lysates of clinically outdated human platelets by ionic exchange chromatography in CM-Sepharose. The eluated fraction was submitted to the Immunoblot/Slot Blot assay using anti-PDGF-AA and anti-PDGF-BB polyclonal antibodies and was evaluated as to its biological activity through the test of [H 3]-thymidine incorporation in NIH/3T3 cell line fibroblasts in culture. The Immunoblot/Slot Blot assay using anti-PDGF-AA and anti-PDGF-BB antibodies proved the presence of the PDGF in chromatographic cationic fraction. The comparison of biological activities between fiblobrast stimulation assay using recombinant PDGF-AB and partially purified PDGF was demonstrated in 165.796 and 157.567 cpm, respectively. This result, proved the potent mitogenic effect of partially purified PDGF and consequently their evidence about the wound healing activity.

Tendências genéticas para características relacionadas à velocidade de crescimento em bovinos nelore na região nordeste do brasil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A administração precoce de hormônio de crescimento resulta em efeitos deletérios na remodelação ventricular após o infarto agudo do miocárdio

Objective: To assess the effect of growth hormone (GH) on myocardial remodeling in infarcted rats. Methods: This study comprised 24 Wistar rats divided into 3 groups as follows: 1) AMI-GH group - comprising 8 rats that underwent infarction and were treated with GH; 2) AMI group - comprising 8 rats that underwent infarction and received only the diluent of the GH solution; and 3) control group (C group) - comprising 8 rats that underwent simulated infarction. After 30 days, the animals underwent functional study through echocardiography, and the changes in myocardial contractility of the isolated left ventricular (LV) papillary muscle were studied. Results: The echocardiography identified an increase in the diastolic (C=7.32±0.49; AMI=8.50±0.73; AMI-GH=9.34±0.73; P<0.05) and systolic (C=3.38±0.47, AMI=5.16±1.24; AMI-GH=5.96±1.54; P<0.05) diameters (mm) in the LV of the infarcted animals. The AMI-GH group animals had a lower ejection fraction (%) (C=0.9±0.03; AMI=0.76±0.12; AMI-GH=0.72± 0.14; P<0.05 for C vs AMI-GH) compared with those in controls. The study of the isolated left ventricular papillary muscle showed that the AMI-GH group had changes (C=1.50±0.59; AMI= 1.28±0.38; AMI-GH=1.98±0.41; P<0.05 for C vs AMI-GH) only in the tension at rest (TR - g/mm2) and in the time delta for a 50% decrease in the tension developed (TR50, ms) after stimulation with calcium (C=23.75±9.16; AMI=-16.56±14.82; AMI-GH=-4.69±8.39; P<0.05 for C vs AMI-GH) and in the delta of tension developed (TD, g/mm2) after stimulation with isoproterenol (C=0.99±0.17; AMI=0.54±0.62; AMI-GH=0.08±0.75; P<0.05 for C vs AMI-GH) compared with those in control animals. Conclusion: The early administration of GH in the experimental infarction model in rats may result in adverse effects on the process of ventricular remodeling.

Parâmetros genéticos para caracteres de crescimento, de produção e tecnológicos da madeira em clones de Eucalyptus spp

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito da temperatura ambiente e da restrição alimentar protéica ou energética sobre o ganho de peso e crescimento ósseo de frangos de corte

The effect of protein or energy restriction during the second week post-hatching on body weight gain and femur development of broiler chickens reared at different environmental temperatures (18°C, 25°C and 33°C) was studied. From 1 to 7 days of age and after a restriction period broilers were fed on a control diet with 2850 kcal ME/kg and 20% crude protein. From 8 to 14 days of age, two groups of broilers were fed on restricted energy and protein diets with 2565kcal ME/kg and 20% of crude protein or 2850kcal ME/kg and 15% of crude protein, respectively. At 14, 21, 28, 35 and 42 days, the bones were weighed and the length and width of bones measured. The protein restriction reduced the body weight gain and the diameter of bone at second week of life. After 21 days of age no differences between treatments for these traits were observed. The body weight gain and femur growth were not affected by energy restriction. The high temperature (33°C) reduced weight gain and femur diameter from 21 to 42 days of age, and femur length at 42 days of age. The protein restriction at second week or the high environmental temperature after 21 st day of life decreased body weight gain and femur growth of broiler chickens.

Diltiazem não induziu crescimento gengival em ratos. Análise clínica, histológica e histométrica

The administration of calcium channel blockers has been associated with gingival overgrowth. However, there are few studies in humans or animals that evaluated the effect of diltiazem on gingival tissues. The present study assessed the influence of diltiazem, at different dosages and treatment duration, on gingival tissues of rats, using clinical, histological and histometric analyses. Eighty young male rats were separated into eight groups according to the dosage and duration of treatment. Rats were treated for 20 or 40 days with a daily subcutaneous injection of 5, 20 or 50 mg/kg of body weight of diltiazem. The results confirmed that diltiazem did not induce gingival overgrowth in rats. For all animals, the evaluation did not show gingival alterations regardless of the dosages and periods of treatment. The histometric analysis showed no significant change in the area of epithelium and connective tissues, although after 40 days of treatment a decrease in the area of connective tissue was observed, without statistically significant difference from control groups. Within the limits of this study, we suggest that diltiazem did not induce gingival overgrowth.