Selection Functions that Do Not Preserve Normality

The sequence selected from a sequence R(0)R(1)··· by a language L is the subsequence of R that contains exactly the bits R(n+1) such that the prefix R(0)··· R(n) is in L. By a result of Agafonoff, a sequence is normal if and only if any subsequence selected by a regular language is again normal. Kamae and Weiss and others have raised the question of how complex a language must be such that selecting according to the language does not preserve normality. We show that there are such languages that are only slightly more complicated than regular ones, namely, normality is preserved neither by deterministic one-counter languages nor by linear languages. In fact, for both types of languages it is possible to select a constant sequence from a normal one.     

Impact of Melatonin on RAW264.7 Macrophages during Mechanical Strain

The concentration of melatonin is elevated during the night when patients mainly wear removable orthodontic appliances. Next to periodontal ligament fibroblasts and osteoblasts, macrophages react to mechanical strain with an increased expression of inflammatory mediators. Here, we investigated the impact of melatonin on RAW264.7 macrophages exposed to tensile or compressive strain occurring during orthodontic tooth movement in the periodontal ligament. Before exposure to mechanical strain for 4 h, macrophages were pre-incubated with different melatonin concentrations for 24 h, to determine the dependence of melatonin concentration. Afterwards, we performed experiments with and without mechanical strain, the most effective melatonin concentration (25 µM), and the melatonin receptor 2 (MT2) specific antagonist 4P-PDOT. The expression of inflammatory genes and proteins was investigated by RT-qPCR, ELISAs, and immunoblot. Both tensile and compressive strain increased the expression of the investigated inflammatory factors interleukin-1-beta, interleukin-6, tumor necrosis factor alpha, and prostaglandin endoperoxide synthase-2. This effect was inhibited by the addition of melatonin. Incubation with 4P-PDOT blocked this anti-inflammatory effect of melatonin. Melatonin had an anti-inflammatory effect on macrophages exposed to mechanical strain, independent of the type of mechanical strain. As inhibition was possible with 4P-PDOT, the MT2 receptor might be involved in the regulation of the observed effects.     

Statistical evaluation of dye desorption – mixed two- and three-level design and kinetic modeling

Abstract

Biosorption has been shown in the literature to be effective in the removal of dye from aqueous solution. To be fully useful, a desorption process is necessary, which has a direct impact on the process costs. The aim of this work was to evaluate the desorption of the azo dye Acid Yellow 23 adsorbed in a biosorbent obtained from Bombyx mori cocoons. Temperature and pH media were evaluated through a mixed two- and three-level design, using NaOH as desorbing agent. Kinetic desorption was also obtained at the optimized condition. The statistical evaluation of the experimental design showed that the pH has almost two times more influence on the dye desorption than the temperature, with only the linear parameters being statistically significant. Among four kinetic desorption models adjusted to the experimental data, the proposed n-order model was statistically determined as the best representation of the experimental data.     

Cold tolerance of Tineola bisselliella (Lepidoptera: Tineidae) eggs at slow cooling rate

Eggs of T. bisselliella were exposed to sub-zero temperatures at a cooling rate of 2°C/h to a minimum of −20°C. Observed mortality was closely approximated by predictions based on an adapted fixed temperature model. The eggs showed no acclimation during cooling. In combination with thermal conductivity models the mortality model provides a simple method to predict exposure times required to reach the desired level of mortality in the cold disinfestation treatment of a commodity or item. With large items, minimum dimension 50 cm, it is predicted that disinfestation will be achieved before the centre has reached −20°C.     

Computational methods for fracture analysis of heavy-section steel technology (HSST) pressure vessel experiments

This paper summarizes the capabilities and applications of the general-purpose and special-purpose computer programs that have been developed at the Oak Ridge National Laboratory (ORNL) for use in fracture mechanics analyses of HSST pressure vessel experiments. Emphasis is placed on the OCA/USA code, which is designed for analysis of pressurized-thermal-shock (PTS) conditions, and on the ORMGEN/ADINA/ORVIRT system which is used for more general analysis. Fundamental features of these programs are discussed, along with applications to pressure vessel experiments.     

Investigation of the pyrolysis of lead zirconate titanate gels with coupled differential thermal analysis, thermogravimetry and infrared spectroscopy

The pyrolysis of organic components in the sol-gel preparation of lead zirconate titanate (PZT) from lead acetate and zirconium and titanium propanolate in methoxyethanol is studied with simultaneous differential thermal analysis, thermogravimetry and infrared spectroscopy. The first pyrolysis step of the dried PZT gel, yielding acetone and CO2 similar to the pyrolysis of lead acetate, indicates that most of the acetate groups are bonded to Pb2+. In the second step, the remaining organic components are oxidized to CO2 and H2O. The formation of undesired carbon residues during pyrolysis from unhydrolysed alkoxide groups and acetate groups bonded to Zr4+ and Ti4+ can be prevented by steam treatment of the dried gels. Activation energies for the different pyrolysis steps of lead, zirconium and titanyl acetate, lead decanoate and PZT gels are given. © 1998 Kluwer Academic Publishers     

Loss of lifetime due to radiation exposure-averaging problems

The transformation of health care in the United States necessitates developing creative strategies to provide quality and cost-effective care for the critically ill obstetric patient population. A discussion of the care of these patients is presented in a multidisciplinary framework, using a case study to illustrate the management process. The significance of contributions and collaboration of advanced practice nurses in perinatology and critical care in the care management of the critically ill obstetric patient is described. Such strategies as location of the patient and educational preparation for nurses caring for these complex patients are offered for consideration. Implications are described and recommendations are made for administrative and clinical practice.     

Virtual cystoscopy based on helical CT scan datasets: perspectives and limitations

The purpose of the study was to simulate cystoscopy based on three-dimensional helical CT scan datasets in real-time in patients with tumours of the urinary bladder. A helical CT scan with double detector technology was carried out pre-operatively in 11 patients with histologically confirmed carcinoma of the urinary bladder and one patient with chronic cystitis. A non-enhanced scan was first performed, followed by an examination in the early phase of contrast medium enhancement. Further images were acquired after adequate filling of the bladder with contrast medium, approximately 30 min after injection. These data were transferred to a separate graphic computer workstation and reconstructed. The results were then compared with the cystoscopic and histopathological findings. All tumours of the urinary bladder identified at fibreoptic cystoscopy were shown on virtual cystoscopy. The best reconstruction results were obtained from data acquired 30 min after injection of contrast medium. The ureteric orifices were not visualized at virtual cystoscopy. These data lead us to conclude that, at present, virtual cystoscopy has not reached the quality of fibreoptic examination and remains restricted to use in specific cases, for example patients with urethral strictures.