Location of the β-galactosidase of the yeast Kluyveromyces marxianus var. marxianus ATCC 10022

During the growth of Kluyveromyces marxianus var. marxianus ATCC 10022 on lactose, peaks of glucose, but not β-galactosidase activity, were detected in culture medium. Harvested and washed whole cells produced glucose and galactose from lactose, or ortho-nitro-phenol from the chromogenic substrate ortho-nitro-phenyl-β-D-galactopyranoside (ONPG), indicating that β-galactosidase is physically associated with cells. ONPG hydrolysis by whole cells presented a monophasic kinetics (Km 36.6 mM) in lactose exponential growth phase cells, but a biphasic kinetics (Km 0.2 and 36.6 mM) in stationary growth phase cells. Permeabilization with digitonin or disruption of cells from both growth phases led to monosite ONPG hydrolysis (Km 2.2 to 2.5 mM), indicating that β-galactosidase is not located in the periplasm. In addition, the energy inhibitors fluoride or arsenate, as well as the uncouplercarbonyl cyanide m-chlorophenylhydrazone (CCCP) prevented ONPG hydrolysis by whole cells. These findings indicate that energy coupled transmembrane transport is the rate-limiting step for intracellular ONPG cleavage. The taxonomic and physiologic implications of the exclusive intracellular location of β-galactosidase of K. marxianus var. marxianus ATCC 10022 are discussed. © 1996 Kluwer Academic Publishers.

Aspects of the sexual reproduction of the Brazilian arnica (Solidago chilensis Meyen var. megapotamica (D.C.) Cabrera - Asteraceae)

The species is a very popularly used plant as woundwort. Leaves, top flowers and rhizomes are used. The objective of this work is a contribution to the germination study, photoblastism and more adequate temperature for reproduction of the species. The best temperature for the germination was found to be 20°C and no seeds germinated under continuous darkness, within 14 days; therefore, the seeds are positive photoblastics. The seed germination percentage was low, in relation to the mass of the achene produced, varying from 8,2 to 20,0%. The alternated temperatures of 20° and 30°C did not influence the seed germination and the average of the weight of 100 seeds was 0,026 1 g.

VAr planning using genetic algorithm and linear programming

A combined methodology consisting of successive linear programming (SLP) and a simple genetic algorithm (SGA) solves the reactive planning problem. The problem is divided into operating and planning subproblems; the operating subproblem, which is a nonlinear, ill-conditioned and nonconvex problem, consists of determining the voltage control and the adjustment of reactive sources. The planning subproblem consists of obtaining the optimal reactive source expansion considering operational, economical and physical characteristics of the system. SLP solves the optimal reactive dispatch problem related to real variables, while SGA is used to determine the necessary adjustments of both the binary and discrete variables existing in the modelling problem. Once the set of candidate busbars has been defined, the program implemented gives the location and size of the reactive sources needed, if any, to maintain the operating and security constraints.

Tabelas de esperança de vida e fertilidade para Lipaphis erysimi (Kalt.) (Hemiptera: Aphididae) em condições de laboratório e campo

In this study, the aphid Lipaphis erysimi (Kalt) was reared at different temperatures, under laboratory and field conditions, aiming to obtain age-specific life tables. In the laboratory, L. erysimi was fed on kale, Brassica oleracea L. var acephala, and kept in incubators adjusted to 10, 15, 20, 25 and 30°C, 14h photophase and 70±10% RH. The longest mean generation time (T) was observed at 15°C (23.86 days) and the shortest at 30°C (7.18 days), while the smallest net reproductive rate (R0) occurred at 15°C (4.30) and largest one at 25°C (38.29). For the temperatures of 15, 20, 25 and 30°C, the intrinsic rate of natural increase (rm) and the finite rate of increase (λ) were 0.06/1.06, 0.24/1.27, 0.28/1.33 and 0.23/1.25, respectively. The doubling time (DT) at 15, 20, 25 and 30°C were 11.55, 2.80, 2.47, and 3.01 days, respectively. Under field conditions, the net reproductive rate (R0) of L. erysimi was larger in the winter (53.50) than in the summer (40.99), the same being observed for the mean generation time (T), which was 13.85 days in the winter and 7.57 days in the summer. The intrinsic rate of natural increase (rm) and the finite rate of increase (λ) were 0.29/1.34 and 0.40/1.63 for winter and summer, respectively. The doubling time (DT) observed for winter (2.39 days) was larger than the one observed for summer (1.41 days). The temperature affects longevity of L. erysimi and the best parameters of life table of fertility under laboratory conditions are obtained at 25°C. The data obtained in field conditions reinforced this finding. The daily fecundity was higher and longevity was smaller in the summer than in the winter, thus increasing the innate capacity of increasing in number and duplicating the population in a shorter period of time.

Influência do alecrim (Rosmarinus officinallis L.) na atividade de água e oxidação lipídica de peixes de uma espécie de tilápia (Oreochromis ssp-var. vermelha Flórida) submetidos à salga

Salting have been a very utilized fish conservation method, however only in the last years the basic mechanism involved in salting fish has been understood. The objectives of this study were determine the addition in brine salt of rosemary leaves, rosemary extracts and tocopherol, and your action in the followed parameters: water activity (Aw), moisture, ash, salt content and TBARS. The results showed that the addition of antioxidants was difficulted the salt absorption, however didn't have differences between rosemary or tocopherol use. In the salting time of 3 hours the values of Aw and salt levels, was respectively: 0.77±0.01 and 14.42±1.69. for control treatment; 0.85±0.02 and 9.09±1.39for rosemary filtrate; 0.78±0.03 and 10.63±0.69 rosemary without filtrating and 0.85±0.02 and 11.96±1.78 tocopherol, showed that didn't grow indigenous bacterias. Lipid oxidation was evaluated by TBARS and the results showed the oxidative effect of salt and the pro oxidant effects of alls antioxidants used in brine salting.

Retratibilidade da madeira de Pinus caribæa var. hondurensis e de Eucalyptus grandis e suas relações com a umidade e densidade

It had been studied the dimensional variations Pinus caribæa var. hondurensis and Eucalyptus grandiswood, emphasizing the axial, radial, tangential and volumetric shrinkage. The results had shown that the volumetric shrinkage of Pinus and Eucalyptus varied according to an exponential curve, R V=R Vmaxe -ku. The total or maximum volumetric shrinkage showed a linear behavior with the specific gravity on basis of ovendry mass and volume and the same behavior as respect of the specific gravity, where the adjusted equations were, respectively: R vmax = 3,01 + 19,15,oo e R vmax = 1,96 + 24,28,ob. It was also verified that the tangential shrinkage was 1,3 times greater than the radial one and 9,0 times greater than the axial one.

Seleção simultânea de caracteres em progênies de Pinus caribaea Morelet var. bahamensis

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

Efeito do desbaste seletivo sobre a divergência genética em progênies de Pinus caribaea Morelet var. bahamensis

The objective of this work was to study the effect of selective thinning on the genetic divergence in progenies of Pinus caribaea var. bahamensis, aiming to identify the most productive and divergent progenies for the use of improvement program. The test of progenies containing 119 progenies and two commercial controls were planted in March 1990, using 11 × 11 square lattice design, sextuple, partially balanced, disposed in lineal plots with six trees in the spacing of 3,0 × 3,0m. 13 years after planting thinning was realized (selection for DBH), with 50% selection intensity based on Multi-effect index, leaving three trees per plot in all the experiment. The evaluations were done at four situations: A (before the thinning); B (thinned trees); C (remaining trees after thinning) and D (one year after thinning). The analyzed traits were: height, diameter at breast height (DBH), volume, form of stem and wood density. The genetic divergence among the progenies was studied with aid of the canonical variables and of clustering of Tocher method, using the generalized distance matrix of Mahalanobis (D2) as estimate of the genetic similarity. The progenies were grouped in four groups in situation A, fourteen in the situation B, two in the situation C and three in the situation D. The selective thinning of the trees within of the progenies caused a change in the genetic divergence among the progenies, genetically homogenizing the progenies, as demonstrated by the generalized distances of Mahalanobis, clustering of Tocher' and canonical variables methods. The thinning made possible a high uniformity in respect to the relative contribution of the traits for the total genetic divergence. The techniques of clustering were efficient to identify groups of divergent progenies for the use hybridization and little divergent progenies for the use in backcross program.

Efeito do desbaste seletivo nas estimativas de parâmetros genéticos em progénies de Pinus caribaea Morelet var. hondurensis

The objective of this work was to study the effect of selective thinning on the estimates of genetic parameters in progenies of Pinus caribaea var. hondurensis. The progeny test was installed in June 1986, following a 10 × 10, triple square lattice design, containing ten trees in linear plots in 3.0 × 3.0m spacing. Twelve years after the planting, a selective thinning based on Multi-effect index (selection for DBH) was performed, leaving six trees per plot. The assessments were done in four situations: A (before thinning); B (among thinned trees); C (among remnant trees at 13 years of age) and D (two years after the thinning). The following traits were analyzed: total height (H), diameter at breast height (DBH), volume (VOL), stem form (FOR), foxtail (FT), wood density at 1.3 m (WD1) and wood density at the half height (WD2). The thinning led to increase in the estimates of variability among progenies for VOL and decrease for ALT and DBH. There was a high and positive genetic correlation among the growth traits, mainly between DBH and VOL. The latter remained unchanged after thinning. The narrow-sense heritabilities at the individual level, showed a slight increase while at the family mean level had a reduction with the thinning. The estimates of breeding values increased with the thinning. This may lead to an easier identification of the best progenies in further selection.

Determination of crude protein, crude fiber and crude fat in twenty-five genotypes of kale (B. oleracea var. acephala)

The aim of the study was to determine the percentage of crude protein, crude fiber and crude fat (ether extract) of 25 genotypes of kale from the Germplasm Bank of Instituto Agronômico de Campinas and of one genotype grown in the region of Jaboticabal-SP. The plants were cultivated in the field, and the leaves after collection were pre-dried in a convection oven at 65°C for 72 h. Afterward, the leaves were analyzed for crude protein, crude fiber and crude fat (ether-soluble materials). Significant differences were detected among the different genotypes for all the characteristics examined. Of the genotypes studied, six showed more than 30% crude protein: HS-20 (32.56%), Comum (31.70%), Couve de Arthur Nogueira 2 (31.16%), Pires 2 de Campinas (30.63%), Manteiga I-916 (30.36%), and Manteiga de Ribeirao Pires I-2446 (30.03%). In relation to crude fiber, the highest percentage was seen in the genotype Manteiga de Mococa (10.92%), differing significantly from the other genotypes studied. With regard to crude fat, the highest percentage was found in the genotype HS-20 (3.72%), and Pires 1 de Campinas (3.34%). Of the genotypes tested, HS-20 stood out among the others, showing both the highest percentage of protein and fat.

Multi-area decentralized optimal VAr planning using the Dantzig-Wolfe decomposition principle

This paper presents a new methodology for solving the optimal VAr planning problem in multi-area electric power systems, using the Dantzig-Wolfe decomposition. The original multi-area problem is decomposed into subproblems (one for each area) and a master problem (coordinator). The solution of the VAr planning problem in each area is based on the application of successive linear programming, and the coordination scheme is based on the reactive power marginal costs in the border bus. The aim of the model is to provide coordinated mechanisms to carry out the VAr planning studies maximizing autonomy and confidentiality for each area, assuring global economy to the whole system. Using the mathematical model and computational implementation of the proposed methodology, numerical results are presented for two interconnected systems, each of them composed of three equal subsystems formed by IEEE30 and IEEE118 test systems. © 2011 IEEE.

Allelopathic effects of aqueous extract of Brassica napus on germination of seeds of Phaseolus vulgaris

Secondary compounds produced by plants are considered an alternative method of weed suppression but can cause negative effects on crops in succession, especially in a no-tillage system, due to the degradation of crop residues with allelopathic potential. The objective of this work was to analyze the influence of foliar aqueous extracts of Brassica napus on the germination and initial development of seedlings of Phaseolus vulgaris. The extract was prepared as a stock 10 % weight/volume solution, and diluted into treatments of relative concentrations of 100 % (i.e. 10 % w/v stock), 75 %, 50 %, 25 % and 0 % (untreated control consisting of distilled water), in a completely randomized design. The seeds of Phaseolus vulgaris were moistened with the differing concentrated extracts and kept in a germination chamber at 25 °C, with a photoperiod of 12 h for nine days. The variables evaluated were: percentage germinating, first count of germination and germination velocity index, as well the root and hypocotyl length, and fresh and dry mass of the seedlings. The aqueous leaf extracts of Brassica napus did not influence the germination of Phaseolus vulgaris seeds, but did induce the growth of abnormal seedlings by inhibition of secondary roots and reduced prominence of the primary root.

Chemical control of pilea microphylla in euterpe oleraceae nurseries with oxyfluorfen

The açai palm is a Brazilian native species and economically important, grown for the hearts of palm and fruit extraction, as well as the seedling production for ornamental purposes. The weed control is one of the concerns observed in seedling production, which has the artillery plant (Pilea microphylla) with the major and widespread occurrence. Thus, the aim of this trial was to evaluate the selectivity and efficacy of oxyfluorfen in artillery plant control in açai (Euterpe oleracea) seedlings. The experimental design was completely randomized. The treatments were arranged in a 2 x 3 factorial scheme, using 2 types of herbicide application: broadcast spraying (sprayed over total area) and spot spraying (directed to the target) and 3 oxyfluorfen dosages (0, 72 and 144 g of active ingredient ha-1) with four replications. Each experimental unit consisted by one açai palm pot infested by artillery plant. They ere visually evaluated for seedling toxicity and the weed control percentage, at 7, 15, 30, 45 and 60 days after application (DAA). There was 100% control of artillery plant from 15 to 60 DAA for the two tested dosages, regardless of application type. However, 100% control was observed at 7 days, using 1.5 L ha-1 in the spot type. The effects of phytotoxicity from 30 to 60 days was moderate, regardless the application method or dosage.

Production and application of amylases of Rhizopus oryzae and Rhizopus microsporus var. oligosporus from industrial waste in acquisition of glucose

Amylases from Rhizopus oryzae and Rhizopus microsporus var. oligosporus were obtained using agro-industrial wastes as substrates in submerged batch cultures. The enzymatic complex was partially characterised for use in the production of glucose syrup. Type II wheat flour proved better than cassava bagasse as sole carbon source for amylase production. The optimum fermentation condition for both microorganisms was 96 hours at 30°C and the amylase thus produced was used for starch hydrolysis. The product of the enzymatic hydrolysis indicated that the enzyme obtained was glucoamylase, only glucose as final product was attained for both microorganisms. R. oligosporus was of greater interest than R. oryzae for amylase production, taking into account enzyme activity, cultivation time, thermal stability and pH range. Glucose syrup was produced using concentrated enzyme and 100 g L-1 starch in a 4 hours reaction at 50°C. The bioprocess studied can contribute to fungus glucoamylase production and application. © 2013 Institute of Chemistry, Slovak Academy of Sciences.

Parametric VaR with goodness-of-fit tests based on EDF statistics for extreme returns

Parametric VaR (Value-at-Risk) is widely used due to its simplicity and easy calculation. However, the normality assumption, often used in the estimation of the parametric VaR, does not provide satisfactory estimates for risk exposure. Therefore, this study suggests a method for computing the parametric VaR based on goodness-of-fit tests using the empirical distribution function (EDF) for extreme returns, and compares the feasibility of this method for the banking sector in an emerging market and in a developed one. The paper also discusses possible theoretical contributions in related fields like enterprise risk management (ERM). © 2013 Elsevier Ltd.