962 resultados para cassava by-product flour


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The objectives of this research were to evaluate leaf consumption and the developmental time of the larvae of Erynnyis ello (L., 1758) (Lepidoptera, Sphingidae) reared on cassava, in order to obtain information for the integrated management of this pest. The larvae were reared on excised cassava leaves in Petri dishes and later in gerbox, and kept in chambers at 24 ± 2 ºC and 75 ± 10% RH. The total leaf area consumed by the larva to complete its development was 589.67 cm²; each of the five instars consumed, respectively: 1.89 cm²; 5.74 cm²; 17.48 cm²; 76.66 cm²; and 487.90 cm². The consumption by the first three instars was insignificant, and did not reach 5% altogether; the 4th represented 13%; the 5th presented a consumption significantly higher, about 82.7%. The total time for the larval development was 22.61 days, and the duration for each of the five larval instar was, respectively: 4.35; 3.19; 3.32; 4.52; and 4.94 days. The pre-pupal period lasted 2.29 days. Since the highest consumption is by the 5th instar larva, the control should be applied before this age to avoid heavier damages to the cassava crop.

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We consider the dynamic relationship between product market entry regulationand equilibrium unemployment. The main theoretical contribution is combininga Mortensen-Pissarides model with monopolistic competition in the goods marketand individual wage bargaining. Product market competition affects unemploymentvia two channels: the output expansion effect and a countervailing effect dueto a hiring externality. Competition is then linked to barriers to entry. Acalibrated model compares a high-regulation European regime to a low-regulationAnglo-American one. Our quantitative analysis suggests that under individualbargaining, no more than half a percentage point of European unemployment ratescan be attributed to entry regulation.

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The methylotrophic yeast Pichia pastoris is widely used for the expression of heterologous enzymes. While the purity of the desired expression product is of major importance for many applications, we found that recombinant enzymes produced in methanol medium were contaminated by a 37-kDa endogenous yeast protease. This enzyme was completely inhibited by phenylmethanesulfonyl fluoride (PMSF) but not by 1,10-phenanthroline, EDTA, and pepstatin A, suggesting the nature of a serine protease. Its secretion was abolished in P. pastoris strains GS115 and KM71 by specific mutagenesis of a subtilisin gene (SUB2) but not by inactivation of the gene encoding vacuolar proteinase B (PRB). Bioinformatic comparisons of Sub2 protein with subtilisins from other fungal genomes and phylogenetic analyses indicated that this enzyme is not an orthologue of the vacuolar protease cerevisin generally present in yeasts but is more closely related to another putative subtilisin found in a small number of yeast genomes. During growth of P. pastoris, Sub2 was produced as a secreted enzyme at a concentration of 10 microg/ml of culture supernatant after overexpression of the full-length SUB2 gene. During fermentative production of recombinant enzymes in methanol medium, 1 ml of P. pastoris culture supernatant was found to contain approximately 3 ng of Sub2, while the enzyme was not detected during growth in a medium containing glycerol as a carbon source. The mutant strain GS115-sub2 was subsequently used as a host for the production of recombinant proteases without endogenous subtilisin contamination.

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This paper investigates the link between brand performance and cultural primes in high-risk,innovation-based sectors. In theory section, we propose that the level of cultural uncertaintyavoidance embedded in a firm determine its marketing creativity by increasing the complexityand the broadness of a brand. It determines also the rate of firm product innovations.Marketing creativity and product innovation influence finally the firm marketingperformance. Empirically, we study trademarked promotion in the Software Security Industry(SSI). Our sample consists of 87 firms that are active in SSI from 11 countries in the period1993-2000. We use the data coming from SSI-related trademarks registered by these firms,ending up with 2,911 SSI-related trademarks and a panel of 18,213 observations. We estimatea two stage model in which first we predict the complexity and the broadness of a trademarkas a measure of marketing creativity and the rate of product innovations. Among severalcontrol variables, our variable of theoretical interest is the Hofstede s uncertainty avoidancecultural index. Then, we estimate the trademark duration with a hazard model using thepredicted complexity and broadness as well as the rate of product innovations, along with thesame control variables. Our evidence confirms that the cultural avoidance affects the durationof the trademarks through the firm marketing creativity and product innovation.

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In a world with two countries which differ in size, we study theimpact of (the speed of) trade liberalization on firms' profitsand total welfare of the countries involved. Firms correctlyanticipate the pace of trade liberalization and take it intoaccount when deciding on their product choices, which areendogenously determined at the beginning of the game. Competitionin the marketplace then occurs either on quantities or on prices.As long as the autarkic phase continues, local firms are nationalmonopolists. When trade liberalization occurs, firms compete in aninternational duopoly. We analyze trade effects by using twodifferent models of product differentiation. Across all thespecifications adopted (and independently of the price v. quantitycompetition hypothesis), total welfare always unambiguously riseswith the speed of trade liberalization: Possible losses by firmsare always outweighed by consumers' gains, which come under theform of lower prices, enlarged variety of higher average qualitiesavailable. The effect on profits depends on the type of industryanalyzed. Two results in particular seem to be worth of mention.With vertical product differentiation and fixed costs of qualityimprovements, the expected size of the market faced by the firmsdetermines the incentive to invest in quality. The longer the periodof autarky, the lower the possibility that the firm from the smallcountry would be producing the high quality and be the leader in theinternational market when it opens. On the contrary, when trade opensimmediately, national markets do not play any role and firms fromdifferent countries have the same opportunity to become the leader.Hence, immediate trade liberalization might be in the interest ofproducers in the small country. In general, the lower the size of thesmall country, the more likely its firm will gain from tradeliberalization. Losses from the small country firm can arise when itis relegated to low quality good production and the domestic marketsize is not very small. With horizontal product differentiation (thehomogeneous good case being a limit case of it when costs ofdifferentiation tend to infinity), investments in differentiationbenefit both firms in equal manner. Firms from the small country do notrun the risk of being relegated to a lower competitive position undertrade. As a result, they would never lose from it. Instead, firms fromthe large country may still incur losses from the opening of trade whenthe market expansion effect is low (i.e. when the country is very largerelative to the other).

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This paper studies oligopolistic competition in off-patent pharmaceuticalmarkets using a vertical product differentiation model. This model canexplain the observation that countries with stronger regulations havesmaller generic market shares. It can also explain the differences inobserved regulatory regimes. Stronger regulation may be due to a higherproportion of production that is done by foreign firms. Finally, a closelyrelated model can account for the observed increase in prices by patentowners after entry of generic producers.

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The new complex, [Zr(pda)2]n (1, pda2- = N,N'-bis(neo-pentyl)-ortho-phenylenediamide, n = 1 or 2), prepared by the reaction of 2 equiv of pdaLi2 with ZrCl4, reacts rapidly with halogen oxidants to afford the new product ZrX2(disq)2 (3, X = Cl, Br, I; disq- = N,N'-bis(neo-pentyl)-ortho-diiminosemiquinonate) in which each redox-active ligand has been oxidized by one electron. The oxidation products 3a-c have been structurally characterized and display an unusual parallel stacked arrangement of the disq- ligands in the solid state, with a separation of approximately 3 A. Density functional calculations show a bonding-type interaction between the SOMOs of the disq- ligands to form a unique HOMO while the antibonding linear combination forms a unique LUMO. This orbital configuration leads to a closed-shell-singlet ground-state electron configuration (S = 0). Temperature-dependent magnetism measurements indicate a low-lying triplet excited state at approximately 750 cm-1. In solution, 3a-c show strong disq--based absorption bands that are invariant across the halide series. Taken together these spectroscopic measurements provide experimental values for the one- and two-electron energies that characterize the pi-stacked bonding interaction between the two disq- ligands.

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We consider the dynamic relationship between product market entry regulation and equilibrium unemployment. The main theoretical contribution is combining a job matchingmodel with monopolistic competition in the goods market and individual wage bargaining.Product market competition affects unemployment by two channels: the output expansion effect and a countervailing effect due to a hiring externality. Competition is then linked to barriers to entry. We calibrate the model to US data and perform a policy experiment to assess whether the decrease in trend unemployment during the 1980 s and 1990 s could be attributed to product market deregulation. Our quantitative analysis suggests that under individual bargaining, a decrease of less than two tenths of a percentage point of unemployment rates can be attributed to product market deregulation, a surprisingly small amount.

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This paper argues that a large technological innovation may lead to a merger wave by inducing entrepreneurs to seek funds from technologically knowledgeable firms -experts. When a large technological innovation occurs, the ability of non-experts (banks) to discriminate between good and bad quality projects is reduced. Experts can continue to charge a low rate of interest for financing because their expertise enables them to identify good quality projects and to avoid unprofitable investments. On the other hand, non-experts now charge a higher rate of interest in order to screen bad projects. More entrepreneurs, therefore, disclose their projects to experts to raise funds from them. Such experts are, however, able to copy the projects and disclosure to them invites the possibility of competition. Thus the entrepreneur and the expert may merge so as to achieve product market collusion. As well as rationalizing mergers, the model can also explain various forms of venture financing by experts such as corporate investors and business angels.

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As the prevalence of smoking has decreased to below 20%, health practitioners interest has shifted towards theprevalence of obesity, and reducing it is one of the major health challenges in decades to come. In this paper westudy the impact that the final product of the anti-smoking campaign, that is, smokers quitting the habit, had onaverage weight in the population. To these ends, we use data from the Behavioral Risk Factors Surveillance System,a large series of independent representative cross-sectional surveys. We construct a synthetic panel that allows us tocontrol for unobserved heterogeneity and we exploit the exogenous changes in taxes and regulations to instrumentthe endogenous decision to give up the habit of smoking. Our estimates, are very close to estimates issued in the 90sby the US Department of Health, and indicate that a 10% decrease in the incidence of smoking leads to an averageweight increase of 2.2 to 3 pounds, depending on choice of specification. In addition, we find evidence that the effectovershoots in the short run, although a significant part remains even after two years. However, when we split thesample between men and women, we only find a significant effect for men. Finally, the implicit elasticity of quittingsmoking to the probability of becoming obese is calculated at 0.58. This implies that the net benefit from reducingthe incidence of smoking by 1% is positive even though the cost to society is $0.6 billions.

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Labor market regulations have often being blamed for high and persistentunemployment in Europe, but evidence on their impact remains mixed. Morerecently, attention has turned to the impact of product market regulationson employment growth. This paper analyzes how labor and product marketregulations interact to affect turnover and employment. We present a matchingmodel which illustrates how barriers to entry in the product market mitigatethe impact of labor market deregulation. We, then, use the Italian SocialSecurity employer-employee panel to study the interaction between barriersto entry and dismissal costs. We exploit the fact that costs for unjustdismissals in Italy increased for firms below 15 employees relative to biggerfirms after 1990. We find that the increase in dismissal costs after 1990decreased accessions and separations in small relative to big firms,especially for women. Moreover, consistent with our model, we find evidencethat the increase in dismissal costs had smaller effects on turnover for womenin sectors faced with strict product market regulations.

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Bioactivity of Indonesian mahogany, Toona sureni (Blume) (Meliaceae), against the red flour beetle, Tribolium castaneum (Coleoptera, Tenebrionidae). The insecticidal activity of Toona sureni (Blume) Merr. was evaluated considering repellency, mortality and progeny production of F1 adults of Tribolium castaneum (Herbst, 1797) (Coleoptera, Tenebrionidae). Dried extract of seeds of T. sureni was dissolved in acetone to prepare solution of various concentrations (0.5, 1.0, 2.5 and 5.0%). To test for repellency, the insects were exposed to treated filter paper. Mortality of larvae, pupae and adults was evaluated by the treatment of spraying the insects with different concentrations of T. sureni extract. Residual effect of the extract was also evaluated considering the production of progeny of F1 adults. The highest repellency (93.30%) of T. castaneum occurred at the highest concentration (5.0% suspension of T. sureni); while the lowest (0.0%) repellency occurred at 0.5% suspension after 1 day of treatment. The highest mortality against adults (86.71%), larvae (88.32%) and pupae (85%) occurred at 5% suspension at 8 days after application. There was a negative correlation between the concentrations of T. sureni and the production of F1 adult's progeny of T. castaneum. The highest number of progeny (147) of T. castaneum occurred in the control at 7 days after treatment; and the lowest number of progeny (43) occurred at 5.0% concentration in 1 day after treatment. The results show that T. sureni is toxic to T. castaneum and has the potential to control all stages of this insect in stored wheat.

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In vivo exposure to chronic hypoxia is considered to be a cause of myocardial dysfunction, thereby representing a deleterious condition, but repeated aeration episodes may exert some cardioprotection. We investigated the possible role of ATP-sensitive potassium channels in these mechanisms. First, rats (n = 8/group) were exposed for 14 days to either chronic hypoxia (CH; 10% O(2)) or chronic hypoxia with one episode/day of 1-hr normoxic aeration (CH+A), with normoxia (N) as the control. Second, isolated hearts were Langendorff perfused under hypoxia (10% O(2), 30 min) and reoxygenated (94% O(2), 30 min) with or without 3 microM glibenclamide (nonselective K(+)(ATP) channel-blocker) or 100 microM diazoxide (selective mitochondrial K(+)(ATP) channel-opener). Blood gasses, hemoglobin concentration, and plasma malondialdehyde were similar in CH and CH+A and in both different from normoxic (P < 0.01), body weight gain and plasma nitrate/nitrite were higher in CH+A than CH (P < 0.01), whereas apoptosis (number of TUNEL-positive nuclei) was less in CH+A than CH (P < 0.05). During in vitro hypoxia, the efficiency (ratio of ATP production/pressure x rate product) was the same in all groups and diazoxide had no measurable effects on myocardial performance, whereas glibenclamide increased end-diastolic pressure more in N and CH than in CH+A hearts (P < 0.05). During reoxgenation, efficiency was markedly less in CH with respect to N and CH+A (P < 0.0001), and ratex pressure product remained lower in CH than N and CH+A hearts (P < 0.001), but glibenclamide or diazoxide abolished this difference. Glibenclamide, but not diazoxide, decreased vascular resistance in N and CH (P < 0.005 and < 0.001) without changes in CH+A. We hypothesize that cardioprotection in chronically hypoxic hearts derive from cell depolarization by sarcolemmal K(+)(ATP) blockade or from preservation of oxidative phosphorylation efficiency (ATP turnover/myocardial performance) by mitochondrial K(+)(ATP) opening. Therefore K(+)(ATP) channels are involved in the deleterious effects of chronic hypoxia and in the cardioprotection elicited when chronic hypoxia is interrupted with short normoxic aeration episodes.

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Counterfeit pharmaceutical products have become a widespread problem in the last decade. Various analytical techniques have been applied to discriminate between genuine and counterfeit products. Among these, Near-infrared (NIR) and Raman spectroscopy provided promising results.The present study offers a methodology allowing to provide more valuable information fororganisations engaged in the fight against counterfeiting of medicines.A database was established by analyzing counterfeits of a particular pharmaceutical product using Near-infrared (NIR) and Raman spectroscopy. Unsupervised chemometric techniques (i.e. principal component analysis - PCA and hierarchical cluster analysis - HCA) were implemented to identify the classes within the datasets. Gas Chromatography coupled to Mass Spectrometry (GC-MS) and Fourier Transform Infrared Spectroscopy (FT-IR) were used to determine the number of different chemical profiles within the counterfeits. A comparison with the classes established by NIR and Raman spectroscopy allowed to evaluate the discriminating power provided by these techniques. Supervised classifiers (i.e. k-Nearest Neighbors, Partial Least Squares Discriminant Analysis, Probabilistic Neural Networks and Counterpropagation Artificial Neural Networks) were applied on the acquired NIR and Raman spectra and the results were compared to the ones provided by the unsupervised classifiers.The retained strategy for routine applications, founded on the classes identified by NIR and Raman spectroscopy, uses a classification algorithm based on distance measures and Receiver Operating Characteristics (ROC) curves. The model is able to compare the spectrum of a new counterfeit with that of previously analyzed products and to determine if a new specimen belongs to one of the existing classes, consequently allowing to establish a link with other counterfeits of the database.