Automatic generation of quadrilateral finite element meshes

This paper describes an efficient, accurate and simple implementation of an algorithm for generation of quadrilateral finite element meshes. An original algorithm by Talbert and Parkinson [J.A. Talbert, A. Parkinson, Development of an automatic two-dimensional finite element mesh generator using quadrilateral elements and Bezier curve boundary definition, Int. J. Numer. Meth. Eng., 29 (1990) 1551–1567], has been substantially redeveloped and modified and presented in greater detail. We cover several important issues omitted in publication mentioned and we will provide interested readers with fully documented source code of the program.     

Interactions of CO and NO with the perovskite-type oxide larho3

Some aspects of the interactions of CO and NO with LaRhO₃ have been studied. The reduction of this oxide with CO occurs where the contracting sphere model is of perovskite structure stable up to a concentration of anion vacancies of ca. 2e^? per molecule. By reduction of LaRhO₃ at 817 K, rhodium was obtained, highly dispersed on a matrix of La₂O_3. After a reduction-oxidation cycle at 871 K the particle size of the perovskite decreased drastically. The activation energy of the reduction (67 kJ mol^?1) was significantly lower than that of other LaMO₃ oxides of group-VIII metals. Coverages of CO(θ_CO) and NO(θ_NO) at room temperature were lower than 3%, θ_NO being substantially higher than θ_CO. The reversibly adsorbed fractions of CO and NO underwent a remarkable decrease after preadsorbing NO and CO, respectively. This competitive adsorption is assumed to be associated with the adsorption of CO and NO on metallic sites. NO preadsorption inhibited the total adsorption of CO more severely than the reverse, indicating that NO is bound more strongly than CO to the LaRhO₃ surface.     

Postgraduate occupations of psychology major students.

During the last ten or fifteen years we have seen an increase in enrollment in undergraduate psychology courses that is far out of proportion to the general increase in overall university attendance. Psychology departments are overwhelmed with undergraduate students, and the numbers continue to increase each year. Since we are allocating so much of our time, energy, and resources to undergraduate teaching, it is important to determine what these students are being educated for. This note reports the results of an inquiry into the postgraduate occupations of the members of the first three graduating classes of the psychology major programme at McGill University. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spectral degree of coherence of a random three-dimensional electromagnetic field

The complex spectral degree of coherence of a general random, statistically stationary electromagnetic field is introduced in a manner similar to the way it is defined for a beamlike field, namely, by means of Young's interference experiment. Both its modulus and its phase are measurable. We illustrate the definition by applying it to blackbody radiation emerging from a cavity. The results are of particular interest for near-field optics.     

Liquid chromatography with mass spectrometry in tandem mode applied for the identification of wine markers in residues from ancient Egyptian vessels

Presented in this paper is a new method for the identification of tartaric acid as a wine marker in archaeological residues from Egyptian vessels using liquid chromatography with mass spectrometry in tandem mode (LC/MS/MS). Owing to the special characteristics of these samples, such as the dryness and the small quantity available for analysis, it was necessary to have a very sensitive and highly specific analytical method to detect tartaric acid at trace levels in the residues. Furthermore, an alkaline fusion was carried out to identify syringic acid derived from malvidin as a red wine marker, in a deposit residue from a wine jar found at the tomb of king Tutankhamun. Malvidin-3-glucoside, the main anthocyanin that gives young wines their red color, polymerizes with aging into more stable pigments. However, the presence of malvidin in ancient residues can be proved by alkaline fusion of the residue to release syringic acid from the pigment, which has been identified, here for the first time, by using the LC/MS/MS method revealing the red grape origin of an ancient Egyptian wine residue.     

Microbiological and biochemical changes in minimally processed fresh-cut Conference pears

Fresh-cut Conference pears were packaged under different modified atmosphere packaging (MAP) conditions and stored in refrigeration. The effects of packaging atmospheres on the microbial viability as well as on the changes in acidity, sugars and ascorbic acid (AA) were studied throughout storage. The use of plastic bags of a permeability of 15 cm ³ O ₂ m ^-2bar ^-1 24 h ^-1 and initial atmospheres of 0 kPa O ₂ extended the microbiological shelf life of pear cubes for at least 3 weeks of storage. Under these conditions, AA levels were kept almost unvaried throughout storage due to the restrictions in the O ₂ availability inside the bags' headspaces. However, these conditions also triggered physiological and biochemical changes that caused greater changes in the product acidity. The sugar profile was also affected by storage, but MAP did not show any significant influence on the reported changes.     

Treatment of brines by combined Fenton's reagent-aerobic biodegradation. II. Process modelling

Process modelling of the integrated Fenton's reagent-aerobic biodegradation system has been carried out by considering a detailed reaction mechanism for the chemical oxidation step and the generalised Monod equation for the biological treatment. Chemical oxygen demand has been contemplated as a pseudo-component for simulation purposes. The proposed mechanism takes into consideration different features experimentally found. Thus, the inefficient hydrogen peroxide decomposition into oxygen and water, the influence of temperature and other operating variables and the role of oxygen have been considered. The aerobic biodegradation of the effluent after the chemical oxidation has taken place has been well simulated by Monod equation with no inhibitory terms. Dependency on temperature has been correlated by Arrhenius expression.     

Evaluation of bacterial RNase P RNA as a drug target

RNA has gained increasing importance as a therapeutic target. However, so far mRNAs rather than stable cellular RNAs have been considered in such studies. In bacteria, the tRNA-processing enzyme RNase P has a catalytic RNA subunit. Fundamental differences in structure and function between bacterial and eukaryotic RNase P, and its indispensability for cell viability make the bacterial enzyme an attractive drug target candidate. Herein we describe two approaches utilized to evaluate whether the catalytic RNA subunit of bacterial RNase P is amenable to inactivation by antisense-based strategies. In the first approach, we rationally designed RNA hairpin oligonucleotides targeted at the tRNA 3'-CCA binding site (P15 loop region) of bacterial RNase P RNA by attempting to include principles derived from the natural CopA-CopT antisense system. Substantial inactivation of RNase P RNA was observed for Type A RNase P RNA (such as that in Escherichia coli) but not for Type B (as in Mycoplasma hyopneumoniae). Moreover, only an RNA oligonucleotide (Eco 3') complementary to the CCA binding site and its 3' flanking sequences was shown to be an efficient inhibitor. Mutation of Eco 3' and analysis of other natural RNase P RNAs with sequence deviations in the P15 loop region showed that inhibition is due to interaction of Eco 3' with this region and occurs in a highly sequence-specific manner. A DNA version of Eco 3' was a less potent inhibitor. The potential of Eco 3' to form an initial kissing complex with the P15 loop did not prove advantageous. In a second approach, we tested a set of oligonucleotides against E. coli RNase P RNA which were designed by algorithms developed for the selection of suitable mRNA targets. This approach identified the P10/11-J11/12 region of bacterial RNase P RNA as another accessible region. In conclusion, both the P15 loop and P10/11-J11/12 regions of Type A RNase P RNAs seem to be promising antisense target sites since they are easily accessible and sufficiently interspersed with nonhelical sequence elements, and oligonucleotide binding directly interferes with substrate docking to these two regions.     

Apoptosis in interface membranes of aseptically loose total hip arthroplasty

The terminal events leading to periprosthetic osteolysis are multifactorial in nature and modulation of this process after the stage of osteolytic mediator release has been futile. Recently, the demonstration of the ability of bisphosphonates to inhibit bone resorption that is mediated by particle-stimulated macrophages and their induction of osteoclast apoptosis suggests a potent area for modulation of osteolysis at the prosthesis-bone interface. The purpose of this study was to determine the mode of cell death that occurs at the osteolytic interface of failed total hip arthroplasty (THA). TUNEL staining, DNA laddering, and immunodetection of poly(ADP-ribose)polymerase (PARP) protein were used to identify the presence of apoptosis in interface membranes from 25 patients aged 28–88 years old (mean, 58 years) harvested at the time of hip revision surgery. Our results demonstrated positive TUNEL stain in 100% of specimens with an average 37% of cells (range 12–60%) positively stained for TUNEL whereas less than 8% of control tissue cells showed positive staining. DNA laddering, a characteristic feature of apoptotic cells, was observed in 82% (28/34) of specimens studied at both the acetabular and femoral side of aseptically loose THAs. No laddering was observed in control tissues. Finally, using Western blot analysis, we observed the appearance of the 89 kDa PARP fragment associated with apoptosis in 92% of specimens (30/33). Our results demonstrate the presence of apoptotic cell death in interface membranes of THAs suggesting that apoptosis-related events are indeed associated with periprosthetic osteolysis and could serve as a specific target point for therapeutic modulation. © 2001 Kluwer Academic Publishers