Domestication of Plants of Ugni molinae Turcz (Myrtaceae) Interferes in the Biology of Chilesia rudis (Lepidoptera: Erebidae) Larvae

In terms of the domestication process in murtilla, studies have found changes in the concentration of phenolic compounds, with reduction of chemical defense of plants, depending on the change in the feeding behavior of insects. Thus, we hypothesized that the domestication of Ugni molinae decreases the content of phenolic compounds and modifies the feeding preference of Chilesia rudis larvae. Leaves of three parental ecotypes and four cultivated ecotypes were used in preference experiments to evaluate the mass gain and leaves consumption of larvae. Phenolic extracts from leaves of U. molinae were analyzed by HPLC. Identified compounds were incorporated in an artificial diet to assess their effect on mass gain, consumption, and survival of the larvae. The presence of phenolic compounds in bodies and feces was also evaluated. In terms of choice assays, larvae preferred parental ecotypes. Regarding compounds, vanillin was the most varied between the ecotypes in leaves. However, plant domestication did not show a reduction in phenolic compound concentration of the ecotypes studied. Furthermore, there was no clear relation between phenolic compounds and the performance of C. rudis larvae. Whether this was because of sequestration of some compounds by larvae is unknown. Finally, results of this study could also suggest that studied phenolic compounds have no role in the C. rudis larvae resistance in this stage of murtilla domestication process.     

Breakpoint Analysis for the COVID-19 Pandemic and Its Effect on the Stock Markets

In this research, statistical models are formulated to study the effect of the health crisis arising from COVID-19 in global markets. Breakpoints in the price series of stock indexes are considered. Such indexes are used as an approximation of the stock markets in different countries, taking into account that they are indicative of these markets because of their composition. The main results obtained in this investigation highlight that countries with better institutional and economic conditions are less affected by the pandemic. In addition, the effect of the health index in the models is associated with their non-significant parameters. This is due to that the health index used in the modeling would not determine the different capacities of the countries analyzed to respond efficiently to the pandemic effect. Therefore, the contagion is the preponderant factor when analyzing the structural breakdown that occurred in the world economy.     

Infrared Spectroscopy as Alternative to Wet Chemical Analysis to Characterize Eucalyptus globulus Pulps and Predict Their Ethanol Yield for a Simultaneous Saccharification and Fermentation Process

Bioethanol can be obtained from wood by simultaneous enzymatic saccharification and fermentation step (SSF). However, for enzymatic process to be effective, a pretreatment is needed to break the wood structure and to remove lignin to expose the carbohydrates components. Evaluation of these processes requires characterization of the materials generated in the different stages. The traditional analytical methods of wood, pretreated materials (pulps), monosaccharides in the hydrolyzated pulps, and ethanol involve laborious and destructive methodologies. This, together with the high cost of enzymes and the possibility to obtain low ethanol yields from some pulps, makes it suitable to have rapid, nondestructive, less expensive, and quantitative methods to monitoring the processes to obtain ethanol from wood. In this work, infrared spectroscopy (IR) accompanied with multivariate analysis is used to characterize chemically organosolv pretreated Eucalyptus globulus pulps (glucans, lignin, and hemicellulosic sugars), as well as to predict the ethanol yield after a SSF process. Mid (4,000–400 cm^?1) and near-infrared (12,500–4,000 cm^?1) spectra of pulps were used in order to obtain calibration models through of partial least squares regression (PLS). The obtained multivariate models were validated by cross validation and by external validation. Mid-infrared (mid-IR)/NIR PLS models to quantify ethanol concentration were also compared with a mathematical approach to predict ethanol yield estimated from the chemical composition of the pulps determined by wet chemical methods (discrete chemical data). Results show the high ability of the infrared spectra in both regions, mid-IR and NIR, to calibrate and predict the ethanol yield and the chemical components of pulps, with low values of standard calibration and validation errors (root mean square error of calibration, root mean square error of validation (RMSEV), and root mean square error of prediction), high correlation between predicted and measured by the reference methods values (R ² between 0.789 and 0.997), and adequate values of the ratio between the standard deviation of the reference methods and the standard errors of infrared PLS models relative performance determinant (RPD) (greater than 3 for majority of the models). Use of IR for ethanol quantification showed similar and even better results to the obtained with the discrete chemical data, especially in the case of mid-IR models, where ethanol concentration can be estimated with a RMSEV equal to 1.9 g?L^?1. These results could facilitate the analysis of high number of samples required in the evaluation and optimization of the processes.     

Topologically inseparable functions I: Finitary case

Given a finite set A and a distinguished function f: A → A, we study the set of all functions g: A → A that are continuous for all topologies for which f is continuous. The main result is a characterization of the functions f such that this set is trivial, that is, contains only the constant functions and the iterates of f.     

A note about teleparallel supergravity

The supersymmetric extension of teleparallel gravity is discussed. It is found that teleparallel supergravity is equivalent to the usual supergravity when the vierbein, the gravitino field and the connection are not identified with the component of the gauge potential, but are obtained taking the limit in (81), (83) and (84) of P. Salgado, S. del Campo, M. Cataldo, Phys. Rev. D 68, 024021 (2003). It is also shown that the successful formalism of Grignani-Nardelli permits one to obtain teleparallel-supergravity in (2 + 1) dimensions from (3 + 1)-dimensional teleparallel supergravity. Received: 11 May 2005, Published online: 6 October 2005 PACS: 04.65. + e     

Topologically Inseparable Functions I: Finitary Case

   Abstract. Given a finite set A and a distinguished function