Effects of phase Separation and devitrification processes in oxide glasses on ESR spectra

The consequences of phase Separation and devitrification processes for the ESR patterns of Fe³⁺ ions and oxygen hole centres in giassy and glassy-crystalline Systems are discussed. Analysis of the Fe³⁺ spectra by Simulation (including 4th order terms) allows their model-based Interpretation for homogeneous, phase-separated and devitrified samples as well. It is even possible to estimate the ratio of Fe³⁺ ions incorporated into the giassy matrix to those localized in the crystalline phase. An influence of irreversible structural reorganization in glasses on γ-irradiation-induced oxygen hole centres is detectable by studying their Saturation behaviour For the example of a barium Silicate glass studied here, pronounced passage effects could be detected at 77 K. In contrast, a devitrified sample of the same composition after γ Irradiation yielded the same spectral pattern at low microwave power, but only Saturation broadening was to be observed when rising the microwave power. In an annealed sample of anorthite composition (in mol%: 25CaO, 25AI₂O₃, 50SiO₂) progressive crystal growth was detectable using Fe³⁺ ions as probes

A heuristic approach for the allocation of resources in large-scale computing infrastructures

An increasing number of enterprise applications are intensive in their consumption of IT, but are infrequently used. Consequently, organizations either host an oversized IT infrastructure or they are incapable of realizing the benefits of new applications. A solution to the challenge is provided by the large-scale computing infrastructures of Clouds and Grids which allow resources to be shared. A major challenge is the development of mechanisms that allow efficient sharing of IT resources. Market mechanisms are promising, but there is a lack of research in scalable market mechanisms. We extend the Multi-Attribute Combinatorial Exchange mechanism with greedy heuristics to address the scalability challenge. The evaluation shows a trade-off between efficiency and scalability. There is no statistical evidence for an influence on the incentive properties of the market mechanism. This is an encouraging result as theory predicts heuristics to ruin the mechanism’s incentive properties. Copyright © 2015 John Wiley & Sons, Ltd

On the interaction of glasses with high-energy radiation - Combined ESR and optical studies

This paper will discuss some aspects of the induced physical processes and chemical reactions which are observed when Silicate and aluminosilicate glasses are exposed to UV radiation (248 nm; excimer laser), γ radiation (⁶⁰Co) and pulses of fast electrons (3.8 MeV). The stimulated emission and absorption of short-lived defects and Čerenkov radiation are detected in the optical ränge between 200 and 800 nm and on the microsecond time scale. Stahle hole centres (Si-0⁻/h⁺, Si-O-Al/h⁺) and electron centres (among others Zn⁺, Cd⁺, (Fe³⁺)⁻) are detected by ESR spectroscopy at room temperature. They show surprising differences in regard to their thermal stability, i.e., the distribution and mean value of their trap depths. Induced absorption in the UV/VIS range exhibits broad and overlapping bands, some of which can be partially assigned to centres detected by ESR spectroscopy. Therefore, UV/VIS spectroscopy provides complementary information, an induced absorption at 300 nm for example, which has no analogy in ESR measurements

An improved behavioural assay demonstrates that ultrasound vocalizations constitute a reliable indicator of chronic cancer pain and neuropathic pain

<p>Abstract</p> <p>Background</p> <p>On-going pain is one of the most debilitating symptoms associated with a variety of chronic pain disorders. An understanding of mechanisms underlying on-going pain, i.e. stimulus-independent pain has been hampered so far by a lack of behavioural parameters which enable studying it in experimental animals. Ultrasound vocalizations (USVs) have been proposed to correlate with pain evoked by an acute activation of nociceptors. However, literature on the utility of USVs as an indicator of chronic pain is very controversial. A majority of these inconsistencies arise from parameters confounding behavioural experiments, which include novelty, fear and stress due to restrain, amongst others.</p> <p>Results</p> <p>We have developed an improved assay which overcomes these confounding factors and enables studying USVs in freely moving mice repetitively over several weeks. Using this improved assay, we report here that USVs increase significantly in mice with bone metastases-induced cancer pain or neuropathic pain for several weeks, in comparison to sham-treated mice. Importantly, analgesic drugs which are known to alleviate tumour pain or neuropathic pain in human patients significantly reduce USVs as well as mechanical allodynia in corresponding mouse models.</p> <p>Conclusions</p> <p>We show that studying USVs and mechanical allodynia in the same cohort of mice enables comparing the temporal progression of on-going pain (i.e. stimulus-independent pain) and stimulus-evoked pain in these clinically highly-relevant forms of chronic pain.</p

An in vitro comparison between two methods of electrical resistance measurement for occlusal caries detection

Because of different measurement techniques and the easier design of the CRM prototype, this in vitro study aimed to compare the diagnostic performance and reproducibility of two electrical methods (Electronic Caries Monitor III, ECM and Cariometer 800, CRM) for occlusal caries detection, and to evaluate the effect of staining/ discoloration of fissures on diagnostic performance. Hundred and seventeen third molars with no apparent occlusal cavitation were selected. Six examiners inspected all specimens independently, using the CRM, and a subgroup of 4 using the ECM. Histological validation using a stereomicroscope was performed after hemisectioning. Intra- and interexaminer reproducibility was assessed by Lin's concordance correlation coefficient (CCC) and Bland and Altman analysis. Diagnostic performance parameters included sensitivity (SE), specificity (SP) and area under the ROC curve (A(z)). The CCC yielded an intra- and interexaminer reproducibility of 0.69/0.62 (ECM) and of 0.79/0.74 (CRM). The mean intra- and interexaminer 95% range of measurements (range between Bland and Altman limits of agreement) given in percentages of the instrument reading were 67%/65% for the ECM and 28%/33% for the CRM. A(z) at the D3-4 level was 0.74 (ECM) and 0.78 (CRM). The CRM showed at least equivalent diagnostic performance to the ECM. However, improvement is still desirable. Diagnostic performance appeared to be enhanced in discolored lesions; however, this may be related to sample lesion distribution characteristics. Copyright (C) 2006 S. Karger AG, Basel

Effects of dental probing on occlusal surfaces - A scanning electron microscopy evaluation

The aim of this clinical-morphological study was to investigate the effects of dental probing on occlusal surfaces by scanning electron microscopy (SEM). Twenty sound occlusal surfaces of third molars and 20 teeth with initial carious lesions of 17- to 26-year-old patients (n = 18) were involved. Ten molars of each group were probed with a sharp dental probe (No. 23) before extraction; the other molars served as negative controls. After extraction of the teeth, the crowns were separated and prepared for the SEM study. Probing-related surface defects, enlargements and break-offs of occlusal pits and fissures were observed on all occlusal surfaces with initial carious lesions and on 2 sound surfaces, respectively. No traumatic defects whatsoever were visible on unprobed occlusal surfaces. This investigation confirms findings of light-microscopic studies that using a sharp dental probe for occlusal caries detection causes enamel defects. Therefore, dental probing should be considered as an inappropriate procedure and should be replaced by a meticulous visual inspection. Critical views of tactile caries detection methods with a sharp dental probe as a diagnostic tool seem to be inevitable in undergraduate and postgraduate dental education programmes. Copyright (c) 2007 S. Karger AG, Basel