Lowpass-bandpass transformation for active RC filters

The conventional lowpass-bandpass transformation (transformation of each element separately) is not applicable to active RC networks because it leads to networks also containing inductors. A modified transformation, including explicit design formulas, will be described, which is applicable to the design of active RC bandpass filters realised by cascading 2nd-order sections.     

Quadrature-modulation-type lowpass and highpass filters

Quadrature-modulation filters, introduced by the author four years ago, can be realised in two different configurations. It is shown that, in the transition bands of the `star?-structured filters, `unwanted? output frequency components (i.e. components not present at the input) are generated, but that, in `lattice-structured? filters, semiequivalent to the corresponding star configuration, such unwanted components are (or can be) suppressed.     

CRKL,AIFM3, AIF,BCL2, and UBASH3A during Human Kidney Development

We aimed to investigate the spatio-temporal expression of possible CAKUT candidate genes CRKL, AIFM3, and UBASH3A, as well as AIF and BCL2 during human kidney development. Human fetal kidney tissue was stained with antibodies and analyzed by fluorescence microscopy and RT-PCR. Quantification of positive cells was assessed by calculation of area percentage and counting cells in nephron structures. Results showed statistically significant differences in the temporal expression patterns of the examined markers, depending on the investigated developmental stage. Limited but strong expression of CRKL was seen in developing kidneys, with increasing expression up to the period where the majority of nephrons are formed. Results also lead us to conclude that AIFM3 and AIF are important for promoting cell survival, but only AIFM3 is considered a CAKUT candidate gene due to the lack of AIF in nephron developmental structures. Our findings imply great importance of AIFM3 in energy production in nephrogenesis and tubular maturation. UBASH3A raw scores showed greater immunoreactivity in developing structures than mature ones which would point to a meaningful role in nephrogenesis. The fact that mRNA and proteins of CRKL, UBASH3A, and AIFM3 were detected in all phases of kidney development implies their role as renal development control genes.     

Compatible high-definition television

Presents an overview of basic signal processing techniques that are being used to develop a MAC-compatible HDTV transmission system, together with the appropriate field rate conversion at the receiver. The processing is much more complex than that used for conventional television. Yet if one compares the complexity of HD-MAC with that employed in some other branches of image processing, the techniques are still relatively simple. One is constrained by what can be done in real time and what can be done at a reasonable cost. Motion compensation is one of a number of new techniques which have only recently been applied to HDTV coding. Very good results have already been achieved and, in the longer term, even better methods will emerge. The transmission standard that is finally adopted must be capable of evolution and contain the headroom to allow the benefits of these developments to be obtained     

Endoscopic features of Helicobacter pylori-related gastritis

BACKGROUND AND STUDY AIMS: It is still controversial whether certain endoscopic features can be used to diagnose Helicobacter pylori (Hp)-related gastritis. To clarify this issue, we performed two consecutive prospective studies. PATIENTS AND METHODS: In the first study, we tried to identify endoscopic criteria associated with Hp-related gastritis from a total of 66 predefined gastric features on endoscopy. These features were selected by a stepwise logistic regression analysis in 101 patients. The validity of these features gained from this first study was then evaluated in a second study in 86 patients (40 with Hp gastritis, 8 with Hp-unrelated gastritis and 38 with normal gastric mucosa). RESULTS: Three features, namely an abnormal antral surface texture, a mammillated corpus surface, and white antral erosions, were identified in the first study as independent predictors of Hp-related gastritis. However, the sensitivity and specificity of these three criteria, as assessed in the second study, were only 75% and 63% respectively. CONCLUSIONS: We conclude that it is not possible to diagnose Hp-related gastritis on the basis of the endoscopic appearance alone. The diagnosis should be based on other criteria, such as a rapid urease test, or a histological examination of gastric biopsies, or both.     

Studying the indoor air quality in three non-residential environments of different use: A museum,a printery industry and an office

The aim of the present study was to identify the main sources contributing to the air pollution of three indoor environments of different use: a museum, a printery industry and an office. For that purpose, particulate matter (TSP, PM₁₀, PM_2.5), inorganic pollutants (NO_x, SO₂, O₃) and organic compounds (BTX, formaldehyde) were monitored. Factors such as the kind of the activities occurred indoors, the emissions from the existing equipment, the number of occupants, the ventilation pattern and the outdoor background substantially varied among the three sites.     

Association of subjective health symptoms with indoor air quality in European office buildings: The OFFICAIR project

The aim of this study was to explore the association between the building-related occupants’ reported health symptoms and the indoor pollutant concentrations in a sample of 148 office rooms, within the framework of the European OFFICAIR research project. A large field campaign was performed in 37 office buildings among eight countries, which included (a) 5-day air sampling of volatile organic compounds (VOCs), aldehydes, ozone, and NO₂ (b) collection of information from 1299 participants regarding their personal characteristics and health perception at workplace using online questionnaires. Stepwise and multilevel logistic regressions were applied to investigate associations between health symptoms and pollutant concentrations considering personal characteristics as confounders. Occupants of offices with higher pollutant concentrations were more likely to report health symptoms. Among the studied VOCs, xylenes were associated with general (such as headache and tiredness) and skin symptoms, ethylbenzene with eye irritation and respiratory symptoms, a-pinene with respiratory and heart symptoms, d-limonene with general symptoms, and styrene with skin symptoms. Among aldehydes, formaldehyde was associated with respiratory and general symptoms, acrolein with respiratory symptoms, propionaldehyde with respiratory, general, and heart symptoms, and hexanal with general SBS. Ozone was associated with almost all symptom groups.     

The application of parallel projections to three-dimensional object location in industrial assembly

Flexible industrial assembly under visual control requires fast and simple picture processing. Parallel projection optics can help to achieve this because it provides constant size images, high immunity to ambient illumination and easy combination of the results from multiple cameras to determine the position of objects in 3-D space. This paper describes the optical system itself, a simple method of calibration, and the application of the system to a simple problem in 3-D assembly.