662 research outputs found
Requiem auf einen unbeugsamen Politiker: Über J. B. Jeyaretnam und seine Workers'Party
No full textDer folgende Artikel ist ein ungewöhnliches Dokument: Geschrieben in einer zuweilen etwas schwülstigen Rhetorik, merkt man dem Text an, durch welche Schule sein Autor gegangen ist. Devan Nair war einer der profiliertesten Gewerkschafter Singapurs in der Zeit des antikolonialen Kampfes gegen die Briten. Doch er war auch ein früher Weggefährte des späteren Premiers Lee Kuan Yew
A simple model of ac hopping surface conductivity in ionic liquids
No full textThe boundary conditions proposed to discuss the charge exchange taking place in an ionic liquid in contact with non-blocking electrodes are reconsidered in a dynamic situation. Assuming that the variation of the bulk ionic current density depends linearly on the surface value of the ionic current density, the frequency dependence of the phenomenological parameter is determined. The analysis has been performed in the framework where the relaxation times are smaller than a maximum relaxation time τM, and that the response function is independent on the value of the relaxation time. Using simple physical considerations, an expression for the surface conductivity describing the ionic charge exchange at the electrode is obtained. According to our calculations, its frequency dependence is similar to that predicted for the electric conductivity in disordered materials when the mechanism is of the hopping type. From measurements of impedance spectroscopy, by the best fit of the experimental data, the temperature dependence of the hopping time, of the dc surface conductivity, and of the diffusion coefficient are derived. They are in good agreement with the theoretical predictions obtained with the random distribution of surface energy barrier. Keywords: Ionic liquids, Non-blocking electrodes, Electrical impedance spectroscopy, AC hopping surface conductivit
Book Reviews
No full textPiotr Bienkowski and Alan Millard, ed.
Dictionary of the Ancient Near East
Philadelphia: University of Pennsylvania Press, 2000
Reviewed By Brent A. Strawn
Candler School of Theology
Emory University Atlanta, GA
James Limburg
Psalms
Westminster Bible Companion; Louisville: Westminster John Knox, 2000
Reviewed By Brent A. Strawn
Candler School of Theology
Emory University Atlanta, GA
Bass, Dorothy C. and Vol£, Miroslav, editors
Practicing Theology: Beliefs and Practices in Christian Life
Grand Rapids, Mich.: Eerdmans, 2002
Reviewed By Ben Devan
Smith, Mark S. Untold Stories:
The Bible and Ugaritic Studies in the Twentieth Century
Peabody, MA. Hendrickson, 2001
Reviewed By Brent A. Strawn
Candler School of Theology
Emory University Atlanta, G
William DeVan, Preliminaries, 4th Van Cliburn Competition (1973)
No full textKlavierstücke, op. 76. No. 1, Capriccio, F-sharp minor / Brahms -- Études-tableaux, op. 33. No. 6 (No. 3) in E-flat minor / Rachmaninoff -- Night Thoughts (Homage to Ives) / Copland -- Piano sonata no. 6 in D major, K. 284. Allegro / Mozart -- Études, op. 10. No. 1 in C major / Chopin -- Piano sonata no. 28 in A major, op. 101. Etwas lebhaft, und mit der innigsten Empfindung / Beethoven -- Mephisto waltz no. 1, S. 514 / Liszt
What's the problem?: Studies on identifying usability problems in user tests
No full textDuring the process of developing products difficulties in use (usability problems) are hard to predict. This especially holds for interactive products with embedded software. In user tests conducted during the design process analysts try to foresee which problems people will run into when using a product. Once they have identified and understood the problems, product developers may attempt to redesign the product so that the risk of users encountering usability problems will be minimized. Extracting usability problems from observed user behavior in a consistent manner has proven to be very difficult. Not only is it difficult for analysts to analyze all observations in the same way (this is called within-analyst consistency) but different analysts also tend to uncover different usability problems (across-analyst consistency). Within-consistency can be at stake when analysts become tired, less attentive or distracted during the analysis. Across-analyst consistency may also concern issues like differences in analysts' beliefs, values or preferences. In this thesis the focus is at consistency in identifying usability problems in user tests. The DEVAN (DEtailed Video ANalysis) procedure was developed to make such analyses documentable and inspectable. Next, DEVAN and its simplified variant SlimDEVAN were used in an academic setting and in a setting of professional usability labs. The aim was to determine to what extent (Slim)DEVAN exposes possible sources of inconsistency and manages to reduce inconsistencies caused by fatigue, lack of vigilance and distraction. In addition, DEVAN was applied to a comparative study in which the effect of using prototypes (instead of functioning products) in user tests is studied in detail. The thesis demonstrates how user test data analyses suffer from persistent inconsistencies. The use of (Slim)DEVAN allowed for detecting causes of persistent inconsistencies. In the comparative study the use of DEVAN revealed effects of using prototypes in user tests. For reducing less persistent inconsistencies advanced (automated) observation tools and more precise problem criteria are proposed. We suggest that further research should focus on consequences of inconsistencies in actual product development contexts. Eventually this will lead to more insight into the quality aspects of user tests, which in turn may lead to a decrease in the number of users muttering: "What's the problem? Why does this thing not do what I want it to do?"Industrial Design Engineerin
Kallikrein-kinin system in inflammatory bowel diseases: Intestinal involvement and correlation with the degree of tissue inflammation
No full textBACKGROUND: Tissue kallikrein and its natural inhibitor, kallistatin, play opposite roles in the generation of bradykinin, a potent mediator of inflammation. Observations on experimental models and humans with ulcerative colitis suggest a pathogenetic role of the kallikrein-kinin system in inflammatory bowel diseases. AIM: To evaluate tissue kallikrein and kallistatin in intestinal tissue samples from Crohn's disease and ulcerative colitis patients with different degrees of disease involvement. PATIENTS AND METHODS: Full-thickness surgical intestinal samples were obtained from 144 subjects (38 normal controls, 32 inflammatory controls, 38 Crohn's disease, 36 ulcerative colitis) and tested for kallikrein and kallistatin by immunoperoxidase techniques. RESULTS: Compared with controls, kallikrein immunoreactivity was significantly weaker in goblet cells (p=0.0001) and significantly stronger in interstitium (p=0.0001) of the Crohn's disease and ulcerative colitis samples. Kallistatin colocalised with kallikrein, with almost no reactivity in goblet cells but strong reactivity in interstitium of inflammatory bowel disease patients (p=0.0001 versus controls). The kallikrein and kallistatin depletion of goblet cells and the increased interstitial kallikrein and kallistatin reactivity correlated with the degree of tissue inflammation (p=0.0001). Disease-free samples had normal kallikrein and kallistatin patterns. CONCLUSIONS: Kallikrein-kinin system is actively involved in inflammatory bowel disease as a result of the release of kallikrein in the intestinal extracellular space; this involvement correlates with the degree of tissue inflammation. The normal pattern observed in the disease-free samples seems to rule out a genetic defect of kallikrein and kallistatin in inflammatory bowel diseases
Deep learning methods for the analysis of biological electron microscopy images
No full textThe analysis of biological structures in electron microscopy (EM) images is an important task that
can lead to a deeper understanding of cellular processes and disease development, as it is widely
used when researching and diagnosing various diseases such as viral infections and genetic
disorders. However, large-scale manual analysis and quantification of EM images is timeconsuming,
subjective, and error-prone.
Deep learning (DL) techniques have the potential to automate image analysis workflows for
objective quantification of biological structures in EM images. Despite this, deep learning has not
been fully explored in biological EM, as it often requires large amounts of labelled ground truth
datasets. The availability of such data is rather scarce in the biological field, which in turn limits
its applications. To overcome this challenge, this thesis focuses on developing DL methods that
can classify, synthesize, detect, and segment biological structures in EM images in an effective
manner using only small amounts of labelled ground truth data.
The methods developed are intended to provide biologists with an automated quantification and
analytical workflow for routine use. To this end, we leveraged transfer learning techniques to
detect human cytomegalovirus (HCMV) particles in transmission electron microscopy (TEM)
images. Two different transfer learning techniques were investigated to assess their effectiveness
and suitability for this task. Our study provided the proof of principle that transfer learning can be
applied to the development of DL models that allow for the automatic detection of particles in EM
images.
This work was then extended to detect and classify HCMV secondary capsid envelopment stages
in TEM images. Since lack of large high-quality labeled ground truth datasets hampers model
performance, we introduced a technique to generate synthetic TEM images and self-labelling data
as an augmentation method. We could show, that the addition of synthetic data greatly improves
the DL models' learning and generalization capability and in turn, improves particle detection. This
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work speeds up the development of DL-based classification and detection applications, as it
reduces the demands on data labeling.
Finally, we developed a weighted average ensemble method to effectively segment various types
of biological structures in both TEM and scanning electron microscopy (SEM) images using very
small labelled ground truth datasets. Our approach significantly outperformed the standard single
model approach, yielding performance almost similar to expert-labeled data. To make our model
interpretable, we added an explainable component in our ensemble model, which visually
communicates the model’s prediction.
By making these three contributions, we have demonstrated throughout this thesis that it is feasible
to automatically detect, synthesize, classify, and segment biological structures in EM images in an
effective manner with a reduced number of expert labels. We hope this will help researchers and
practitioners optimize routine analytical workflows for biological EM quantification
Studies of the degradation behaviour of Gamma-TiAl and Fe3Al intermetallics
No full textThe oxidation behaviour of Fe3A1 intermetallic alloys with and without reactive element (RE) and Ti-46.7A1-1.9W-0.5Si alloy over the temperature ranges of 900 to 1100°C and 750 to 950°C respectively were studied for up to 240h. The isothermal and cyclic oxidation behaviour of Fe3A1 intermetallic materials was studied in static air. The Al203 adherence of (Y and/or Hf)-doped Fe3A1 alloys was examined using newly developed — by the researcher — cyclic oxidation rig built in AMRI's laboratory. However the oxidation of Ti-46.7A1-1.9W-0.5Si alloy was studied in air and under Ar-02 atmospheres of three oxygen partial pressures; P02 = (0.05, 0.2 and 0.8) x 105 Pa. Isothermal sulphidation/oxidation work of coated — with specially designed single and multi- layer coatings — and uncoated Ti-46.7A1-1.9W-0.5Si alloy was performed in relatively high partial pressure of sulphur (pS2 = 6.8 x 10-1 Pa) and low partial pressure of oxygen (p02 = 1.2 x 10-15 Pa) at 850° C for up to 240h. Characterisation of the specimens was conducted using SEM, EDX, and XRD techniques. Higher oxidation rates of Ti-46.7A1-1.9W-0.5Si alloy were observed in air than in Ar-20%02 at all temperatures. The scale formed in air consisted of Ti02/Al203/Ti02/TiN/TiAl2/substrate, whilst the scale developed in Ar-20%02 atmosphere was comprised of Ti02/Al203/Ti02/Al203/Ti3A1/substrate. The oxidation rates of Ti-46.7A1-1.9W¬0.5Si alloy increased with decreasing the oxygen partial pressure in Ar-02 atmospheres at the entire range of temperatures. The employment of single A1TiN and CrN single layer coatings improved the sulphidation/oxidation behaviour of Ti-46.7A1-1.9W-0.5Si alloy at 850°C for up to 240h in H2/H20/H2S gas mixture. However, the use of NbN and CrN diffusion barrier coatings significantly enhanced its corrosion resistance. The scale on uncoated Ti-46.7A1-.9W-0.5Si alloy in sulphidising/oxidising atmosphere consisted of Ti02/Al203/TiS+W/TiA13/TiAl2/substrate. The reactive element (RE) — Y and/or Hf — addition especially Y significantly improved the oxide adherence of Fe3A1 over the specified range of temperature and exposure time (or cycles). However, higher oxidation rate of Fe3A1 alloys doped with Y was obtained under both isothermal and cyclic oxidation. Although the scale thickness of Hf-doped alloy was always higher than that of Y-doped alloys, the oxidation rate constant of the later is found in some cases to be less than that of the first by one order of magnitude. However, the scale on the Hf-doped alloy is relatively adherent to the substrate if compared with the scale of undoped Fe3A1 alloy even at the areas where oxide pegs were observed on Fe3A1-Hf alloy. Generally, no conclusion could be taken from the kinetic data of Fe3A1 alloys regarding the reactive element effect (REE) due to the intergranular attack on the Y-containing alloys. Improving the interface properties by RE addition led to a better control of the outward diffusion of aluminium and eliminated the detrimental effect of sulphur (possibly present in the Fe3A1 alloys). However, the presence of the RE in the alloy led to the formation of coherent scales. At 1100°C and after prolonged exposure, the scale of RE- doped alloys was not able to remain in contact with the substrate especially under thermal cycling conditions. The external scale severely cracked especially at places where oxide ridges were formed. The Y-containing Fe3A1 alloys were capable of producing another thin and adherent scale underneath the cracked external scale
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