Efficient algorithms for descendant-only tree pattern queries

Tree pattern matching is a fundamental problem that has a wide range of applications in Web data management, XML processing, and selective data dissemination. In this paper we develop efficient algorithms for the tree homeomorphism problem, i.e., the problem of matching a tree pattern with exclusively transitive (descendant) edges. We first prove that deciding whether there is a tree homeomorphism is LOGSPACE-complete, improving on the current LOGCFL upper bound. Furthermore, we develop a practical algorithm for the tree homeomorphism decision problem that is both space- and time-efficient. The algorithm is in LOGDCFL and space consumption is strongly bounded, while the running time is linear in the size of the data tree. This algorithm immediately generalizes to the problem of matching the tree pattern against all subtrees of the data tree, preserving the mentioned efficiency properties.     

Study on microstructural, chemical and electrical properties of tantalum nitride thin films deposited by reactive direct current magnetron sputtering

The properties of tantalum nitride (TaN_x) thin films on silicon and low temperature co-fired ceramics based substrates were investigated with respect to their potential use for sensor elements operated under harsh environmental conditions. For deposition reactive direct current magnetron sputtering was applied at constant back pressure (=0.9 Pa) and plasma power (=1,000 W). In all experiments, the substrates were nominally unheated. The films were investigated electrically by four point probing. For morphological and chemical analyses, a large variety of techniques such as focussed ion beam, scanning electron microscopy, X-ray diffraction, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy and glow discharge optical emission spectroscopy were used. Only by combining all these techniques for analysing TaN_x films synthesised with varying nitrogen content in the deposition chamber can a proper evaluation of the microstructure and the chemical composition be done. Both the microstructure and the chemical composition are influenced strongly with a resulting effect on the electrical film properties.     

Analysis and application of heavy isotopes in the environment

A growing number of AMS laboratories are pursuing applications of actinides. We discuss the basic requirements of the AMS technique of heavy (i.e., above ～150 amu) isotopes, present the setup at the Vienna Environmental Research Accelerator (VERA) which is especially well suited for the isotope ²³⁶U, and give a comparison with other AMS facilities. Special emphasis will be put on elaborating the effective detection limits for environmental samples with respect to other mass spectrometric methods.At VERA, we have carried out measurements for radiation protection and environmental monitoring (²³⁶U, ^{239,240,241,242,244}Pu), astrophysics (¹⁸²Hf, ²³⁶U, ²⁴⁴Pu, ²⁴⁷Cm), nuclear physics, and a search for long-lived super-heavy elements (Z > 100). We are pursuing the environmental distribution of ²³⁶U, as a basis for geological applications of natural ²³⁶U.     

Real-time processing of serial stimuli in classical conditioning of the rabbit's nictitating membrane response.

Real-time models contend that a CS gives rise to a cascade of hypothetical stimuli that govern CRs on a moment-to-moment basis. Experiments with the rabbit nictitating membrane response successfully extended these models to external stimuli. CRs were trained in sequence with an unconditioned stimulus/stimuli (UCS) (CSA–CSB–UCS). When the CSA–CSB interval was shortened, the CR was compressed; when the CSA–CSB interval was lengthened, the CR was broadened. Peaks appeared at 2 places, namely, one following CSA by a period equal to the CS–UCS interval and another following CSB by its CS–UCS interval. Outside the sequence, the individual CSs evoked CRs located between their respective CS–UCS intervals. When, however, the 2 CSs were trained separately, the CRs were appropriate to their respective CS–UCS intervals when tested alone or in sequence. The results are discussed in terms of the J. E. Desmond and J. W. Moore (1988) and S. Grossberg and N. A. Schmajuk (1989) models. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interactions of team mental models and monitoring behaviors predict team performance in simulated anesthesia inductions.

In the present study, we investigated how two team mental model properties (similarity vs. accuracy) and two forms of monitoring behavior (team vs. systems) interacted to predict team performance in anesthesia. In particular, we were interested in whether the relationship between monitoring behavior and team performance was moderated by team mental model properties. Thirty-one two-person teams consisting of anesthesia resident and anesthesia nurse were videotaped during a simulated anesthesia induction of general anesthesia. Team mental models were assessed with a newly developed measurement tool based on the concept-mapping technique. Monitoring behavior was coded by two organizational psychologists using a structured observation system. Team performance was rated by two expert anesthetists using a performance-checklist. Moderated multiple regression analysis revealed that team mental model similarity moderated the relationship between team monitoring and performance; a higher level of team monitoring in the absence of a similar team mental model had a negative effect on performance. Furthermore, team mental model similarity and accuracy interacted to predict team performance. Our findings provide new insights on factors influencing the relationship between team processes and team performance in health care. When investigating the effectiveness of a specific team coordination behavior, team cognition has to be taken into account. This represents a necessary and compelling extension of the popular process-outcome relationship on which previous teamwork research in health care has focused. Moreover, the current study adds further external validity to the concept of team mental models by highlighting its usefulness in health care. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Count data regression charts for the monitoring of surveillance time series

Control charts based on the Poisson and negative binomial distribution for monitoring time series of counts typically arising in the surveillance of infectious diseases are presented. The in-control mean is assumed to be time-varying and linear on the log-scale with intercept and seasonal components. If a shift in the intercept occurs the system goes out-of-control. Using the generalized likelihood ratio (GLR) statistic a monitoring scheme is formulated to detect on-line whether a shift in the intercept occurred. In the case of Poisson the necessary quantities of the GLR detector can be efficiently computed by recursive formulas. Extensions to more general alternatives e.g. containing an auto-regressive epidemic component are discussed. Using Monte Carlo simulations run-length properties of the proposed schemes are investigated and the Poisson scheme is compared to existing methods. The practicability of the charts is demonstrated by applying them to the observed number of salmonella hadar cases in Germany 2001-2006.     

Classification criteria and probability risk maps: limitations and perspectives

Delineation of polluted zones with respect to regulatory standards, accounting at the same time for the uncertainty of the estimated concentrations, relies on classification criteria that can lead to significantly different pollution risk maps, which, in turn, can depend on the regulatory standard itself. This paper reviews four popular classification criteria related to the violation of a probability threshold or a physical threshold, using annual (1996-2000) nitrogen dioxide concentrations from 40 air monitoring stations in Milan. The relative advantages and practical limitations of each criterion are discussed, and it is shown that some of the criteria are more appropriate for the problem at hand and that the choice of the criterion can be supported by the statistical distribution of the data and/or the regulatory standard. Finally, the polluted area is estimated over the different years and concentration thresholds using the appropriate risk maps as an additional source of uncertainty.     

Optimization of Arabinoxylan Isolation from Rye Bran by Adapting Extraction Solvent and Use of Enzymes

Physicochemical and functional properties of arabinoxylans (AXs) can be significantly influenced by their isolation method. Finding balanced process conditions that allow optimal extraction yields while preserving AXs functionality is a challenge. The aim of this study was to determine the effect of different chemical solvents with neutral and alkaline pH on the intrinsic properties and extraction yield of AXs isolated from rye bran. Additionally, the application of xylanases and other cell wall degrading enzymes (Pentopan Mono BG, Deltazym XL‐VR, Viscoflow BG) to solubilize bound AXs was investigated. Results show that the use of Ca(OH)₂ for isolation was superior to water and Na₂CO₃, as it selectively solubilized AXs and delivered isolates with a purity of up to 43.92% AX and a moderate ferulic acid (FA) content (209.35 ± 16.79 mg FA/100 g AX). Application of xylanases was further able to duplicate these achieved AX yields (7.50 to 9.85g AX/100 g bran). Additionally, isolates displayed highest ferulic acid contents (445.18 to 616.71 mg FA/100 g AX) and lowest impurities in comparison to chemical extracted AXs. Rheological characterization of the isolates showed a pronounced shear thinning behavior which fitted well to the power‐law model (R² > 0.989). Differences in pseudoplasticity of the isolates suggested that structural and chemical properties might have been responsible for this behavior.     

Regulation of aryl hydrocarbon receptor activity in porcine cumulus-oocyte complexes in physiological and toxicological conditions: the role of follicular fluid

The arylhydrocarbon receptor (AhR) mediates the adverse effects of dioxin-like compounds. However, it has also been reported that the AhR may exert a role in ovarian physiology. In the present study, porcine cumulus-oocyte complexes (COCs) were matured in vitro in the presence of 10% follicular fluid. Expression of AhR and its partner, AhR nuclear translocator occurs in immature COCs. After in vitro maturation (IVM), an up-regulation of AhR and cytochrome P450 1A1 (CYP1A1; the main AhR-target gene) was observed. To explore the role of the AhR during IVM, we exposed the COCs to 50 microM beta-napthoflavone (betaNF). The treatment induced a marked up-regulation of CYP1A1 mRNA, indicating both constitutive and inducible AhR activity. However, in contrast to what was observed in other cell types, no sign of toxicity was observed in COCs. To investigate if components of porcine follicular fluid may exert a protective role against AhR ligands, we exposed porcine COCs to betaNF, in the absence of follicular fluid. In these conditions, a marked decrease in the percentage of matured oocytes, concomitant with an increase in oocyte degeneration, was observed. Furthermore, betaNF increased apoptosis in cumulus cells in the absence of follicular fluid, whereas betaNF has no effects when COCs were treated in the presence of porcine follicular fluid (pFF). In conclusion, these results suggest the presence of unknown endogenous AhR-ligand(s) during porcine IVM and that a dysregulation of this mechanism may result in ovotoxicity by inducing apoptosis in cumulus cells. However, this phenomenon is interrupted by the presence of follicular fluid, indicating a putative protective role for follicular fluid components against exogenous insults.