Stress and memory retrieval in women: No strong impairing effect during the luteal phase.

Stress has been shown to impair delayed memory retrieval, but so far no study has been conducted solely with naturally cycling women. In a crossover design, 36 women (all in the luteal phase) participated in two experimental conditions (stress vs. control). Delayed memory retrieval of a wordlist learned 24 hours earlier was tested after stress or control treatment. Although stressed subjects showed a strong cortisol increase following stress, no influence on memory retrieval occurred. In an additional data analysis, subjects were split up into a cortisol responder and a cortisol nonresponder group. However, again no evidence for a stress-induced retrieval impairment became apparent. Similarly, no correlation was observed between the stress-induced cortisol increase and memory. This study failed to find an influence of stress on memory retrieval in women tested in the luteal phase. The findings are in contrast to our previous results obtained with men. Evidence is discussed that the luteal phase, which is characterized by elevated gonadal steroids, is associated with reduced glucocorticoid sensitivity. This might underlie the missing impact of stress on memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Simulation of dynamic phenomena by cellular automata

This paper is aimed at showing how cellular automata can be conveniently employed to simulate dynamic phenomena, typically involving transportation, diffusion, or propagation problems. A cellular automaton can be viewed as made of two parts: a computational engine based on a proper discretization of the domain and charged with correctness and consistency controls, and a dynamic model constituted by transition functions that express cell behaviour. The adoption of cellular automata introduces a new means of spatial data modelling, in addition to those traditionally provided by GIS packages, resulting in the possibility of storing elements of dynamic knowledge in cellular maps: each cell is provided with the attributes that constitute its state, and groups of cells with the functions that describe their mutual interaction. The basic characteristics of cellular automata are discussed with reference to a significant application case, the study of tide propagation over a lagoon.     

Mass transfer coefficients for arranged packings with vertical walls under gas film control

Packings with vertical walls, especially structured packings, are distinguished by their high efficiency and low pressure drop per mass transfer unit. Yet for these types of packings there is still no universal relationship for calculating gas-film-controlled mass transfer coefficients. The present work proposes such an equation. For arranged and structured packings the new equation fits the experimental data, both new results and those taken from the literature, with a mean error of 9%.     

Biodegradation of wood-pulp black liquor hydroxyacids by Micrococcus lylae

When Micrococcus lylae grew on the black liquor from wood pulping, glucoisosaccharinic and acetic acids were completely used in 48 h, 2-hydro-xybutanoic acid decreased by 67%, lactic acid by 45% and glycolic acid by 38%. Conditions of the utilization of glucoisosaccharinic acid were optimized.     

Characterization by Fourier transform infrared spectroscopy of polyethylene adipate/cholesteryl palmitate blends

FT‐IR spectroscopy has been employed to study compatibility, melting, and crystallization of the polyethylene adipate (PEA)/cholesteryl palmitate (CP) blends. The changes in FT‐IR spectra were followed by controlled rate of heating and cooling. The bands corresponding to the crystalline structure have been assigned. The accuracy of the transition temperature determination has been improved by fitting the curve of the integral absorbance dependence on temperature with a Boltzmann function. From dependence of the transition temperatures on the composition of the blend, it has been established that for each mixing ratio a certain mass fraction of CP should be dissolved in the PEA matrix. The PEA/CP blends behave as a phase‐separated system with partial miscibility. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1156–1163, 2004     

AN ALGORITHM FOR A PERIOD SEARCH IN A SPARSELY COVERED TIME SERIES AT A FIXED PHASE

Abstract. Researchers are sometimes faced with a set of observations that constitute a sparse coverage of a time series, suspected to be periodic. The period is unknown, but one can identify in the observed data a few points that are presumed to occur at the same phase, in different cycles of the unknown periodicity. We propose an algorithm that finds all periods which are compatible with such observed data, and suggest how to assess their statistical significance. The algorithm also provides stringent limits on the epochs of the fixed phase. We give three examples, from the field of astronomy, for application of our new algorithm. In the first one the algorithm reveals, on the basis of very few photometric observations, a highly significant period in the light curve of the recent classical Nova Herculis 1991. In the second example, in the series of arrival times of neutrinos from the supernova SN1987A, our algorithm yields a definite negative result. It proves that no significant exact periodicity is present in the data. In the third application, the algorithm provides new constraints on the epoch of one of the minima in the light curve of the stellar binary system 44i Bootis. We compare the method with other period search techniques, pointing out a few of its advantages, as well as some of its weaknesses.     

Different Roles of p62 (SQSTM1) Isoforms in Keratin-Related Protein Aggregation

p62/Sequestosome-1 (p62) is a multifunctional adaptor protein and is also a constant component of disease-associated protein aggregates, including Mallory–Denk bodies (MDBs), in steatohepatitis and hepatocellular carcinoma. We investigated the interaction of the two human p62 isoforms, p62-H1 (full-length isoform) and p62-H2 (partly devoid of PB1 domain), with keratins 8 and 18, the major components of MDBs. In human liver, p62-H2 is expressed two-fold higher compared to p62-H1 at the mRNA level and is present in slightly but not significantly higher concentrations at the protein level. Co-transfection studies in CHO-K1 cells, PLC/PRF/5 cells as well as p62⁻ total-knockout and wild-type mouse fibroblasts revealed marked differences in the cytoplasmic distribution and aggregation behavior of the two p62 isoforms. Transfection-induced overexpression of p62-H2 generated large cytoplasmic aggregates in PLC/PRF/5 and CHO-K1 cells that mostly co-localized with transfected keratins resembling MDBs or (transfection without keratins) intracytoplasmic hyaline bodies. In fibroblasts, however, transfected p62-H2 was predominantly diffusely distributed in the cytoplasm. Aggregation of p62-H2 and p62ΔSH2 as well as the interaction with K8 (but not with K18) involves acquisition of cross-β-sheet conformation as revealed by staining with luminescent conjugated oligothiophenes. These results indicate the importance of considering p62 isoforms in protein aggregation disease.