Power Series Approach to Holistic Sewer System Modeling

Fast and stable mathematical models for the computation of sewer system outflow are essential for real-time control of urban storm drainage systems. This paper presents a general method to design such models based on the reservoir approach. The unknown inflow-outflow function is developed into a power series. The a priori assumptions made for this are much weaker than the ones for the well-known linear models. The resulting models are nonlinear, but they subsume some of the linear models, depending on the selection of model parameters. Thus, a more general approach to validate the frequently made linearity postulation of the outflow process is provided. The new model is tested with some subcatchments of a larger urban storm drainage network.     

Genetic analysis of new progesterone-based fertility traits in dairy cows measured on-farm

The objectives of this study were (1) to analyze the agreement of a standard laboratory ELISA for progesterone (P4) with an automated on-farm ELISA kit operated under commercial conditions in 1,297 milk samples from 50 dairy cows; (2) to study the influence of the method of detection of luteal activity on genetic parameters of fertility traits based on P4 measured with an automated on-farm ELISA once weekly from wk 3 to 9 postpartum in the milk of 1,304 cows; and (3) to study the influence of sampling frequency (once or twice weekly from wk 3 to 9) on the same traits from 296 cows. Luteal activity can be detected when there is an active corpus luteum in the ovary producing P4 and indicating the onset of reproductive cyclicity after calving. The on-farm ELISA overestimated P4 contents by a mean square error of prediction of 2.76 ng/mL and had an intermediate Spearman correlation with the laboratory kit (0.54). For the second objective, the postpartum interval to the commencement of luteal activity (C-LA), proportion of luteal activity between d 15 and 63 postpartum (P-LA), calculated as the number of samples above the threshold for high P4 values divided by the number of all samples, and delay of first ovulation (DOV1), defined as C-LA occurring later than d 45 postpartum, were derived from the P4 profiles. Both C-LA and DOV1 were determined by (a) thorough qualitative visual inspection of the profile, (b) the profile's mean as threshold for the first increase in P4 postpartum, indicating commencement of luteal activity, and (c) 3 ng/mL as threshold for the first increase in P4, a value that has been used by many other studies. Similarly, P-LA was determined by using methods (b) and (c). Estimates of heritability were 0.04 to 0.13 for C-LA, 0.12 to 0.23 for P-LA, and 0.03 to 0.07 for DOV1. Genetic correlation of P-LA with C-LA and with the profile's mean P4 was ?1.00. The profile's mean had a higher estimate of heritability (0.11–0.12) than C-LA or DOV1. It can be calculated as the arithmetic mean of all P4 values of a profile, whereas C-LA, P-LA, and DOV1 need a definition of a threshold for high P4 values. We therefore suggest the profile's mean as a promising candidate for further research. For the third objective, once-weekly sampling was mimicked by neglecting every second sample, and C-LA and DOV1 shifted toward a later onset of cyclicity. Thus, a common standard for sampling regimen and detection algorithm is essential to avoid incompatibility between studies.     

Operational detection of contrails from NOAA-AVHRR-data

This paper describes a fully automated scheme that allows for the detection of contrails using the infrared channels of the Advanced Very High Resolution Radiometer (AVHRR). The presented algorithm is adjusted to have a low rate of misdetection in spite of the low contrail detection efficiency resulting from this tuning. A time-series and regional patterns of contrail cloudiness over Central and Western Europe are derived. Daily analysis of noon scenes in 1996 indicates that the average of daytime contrail coverage over Central Europe was 0.5% 0.25 with regional maxima of 1.2%. Comparing noon and midnight scenes shows that night-time contrail coverage, which is especially effective in greenhouse forcing, is approximately one-third of that of daytime.     

Electronic Properties as a Function of Ag/Sb Ratio in Ag1?y Pb18Sb1+z Te20 Compounds

In this study efforts have been made to optimize the electronic properties such as the electrical conductivity and Seebeck coefficient of Ag_{1? y} Pb₁₈Sb_{1+ z} Te₂₀ (lead-antimony-silver-tellurium, LAST-18) compounds by systematically varying the Ag and Sb compositions with constant Pb/Te ratio. It was found that increasing the content of Sb relative to Ag raised the charge carrier density (n) and thereby the electrical conductivity and power factor. The results indicate that, for deficient Ag, the excess trivalent Sb atoms occupy divalent Pb sites in the unit cell, increasing the value of n in the system. It was established that the Seebeck coefficient decreases with increasing n, indicating a dominant acoustic phonon scattering mechanism in the current alloys. The results demonstrate that the interaction between Ag and Sb atoms plays a major role in determining the electronic properties in the current Ag_1?y Pb₁₈Sb_1+z Te₂₀ compounds.     

Improvements in spiral MR imaging

The basic principles of spiral MR image acquisition and reconstruction are summarised with the aim to explain how high quality spiral images can be obtained. The sensitivity of spiral imaging to off-resonance effects, gradient system imperfections and concomitant fields are outlined and appropriate measures for corrections are discussed in detail. Phantom experiments demonstrate the validity of the correction approaches. Furthermore, in-vivo results are shown to demonstrate the applicability of the corrections under in-vivo conditions. The spiral image quality thus obtained was found to be comparable to that obtainable with robust spin warp sequences. Presented in parts at the 15th meeting of the ESMRMB, Geneva, September, 1998.     

Integrating mobile cellular devices into popular peer-to-peer systems

Today, peer-to-peer content-distribution networks are highly popular among users that have stationary computers with high-bandwidth Internet connections. Mobile devices (e.g. cell phones) that are connected to the Internet via cellular-radio networks, however, could not yet be launched into this field to a satisfactory extent. Although most mobile devices have the necessary hardware resources for joining peer-to-peer content-distribution networks, they are often not able to benefit from participation in an energy efficient way, due to limitations caused by mobility. In this work, mobile devices are identified as providers of advanced mobile features and services that are usually not available to computers in stationary networks. These mobile features and services can be exchanged for services in peer-to-peer networks, turning mobile devices into valuable trading partners. Partnership schemes are set up to define the way of a fair cooperation between mobile devices and other peers. A novel peer-to-peer architecture is suggested that applies partnership schemes to a well-established peer-to-peer content-distribution network and facilitates the integration of mobile devices.     

Transformation of austenite into bainitic ferrite and martensite

The stress induced martensitic transformation in the upper metastable intermediate state of γ-α transformation in ferrous materials, structured as ferritic bainite, is discussed. The fibrous structured ferritic bainite consists of retained austenite and ferrite platelets growing in the [111]α//[101]γ direction. The ferrite growth Induces carbon enrichment of the adjacent austenite at the phase boundaries. Strengthening at high stress levels up to the yield point causes dislocation tangles in the ferrite fibre and the formation of shear bands crossing each other in the retained austenite. At lower carbon contents of the austenite, lath martensite precipitates at the shear band intersections and at high shear band densities martensite blocks are observed. In carbon enriched austenite martensite lenses formed by shear processes have been observed. At alternating loading conditions, exceeding the stress level for athermic martensite formation, various shear planes are activated forming characteristic patterns of plate martensite.     

Naming decline after left anterior temporal lobectomy correlates with pathological status of resected hippocampus

PURPOSE: To evaluate the determinants of postoperative change in visual confrontation naming ability and the differential sensitivity of two common tests of confrontation naming. METHODS: In a group of 99 patients undergoing lobectomy of the left, language-dominant anterior temporal lobe, we examined naming ability using two measures: the 60 item Boston Naming Test (BNT), and the Visual Naming (VN) subtest of the Multilingual Aphasia Examination (MAE). ATL entailed resection of lateral temporal lobe followed by microsurgical complete removal of hippocampus. Language mapping was not performed. The status of the resected hippocampus was graded on a scale 0-4 of hippocampal sclerosis (HS). A dichotomous grouping HS- (grades 0 and 1, n = 34) and HS+ (grades 3 and 4, n = 61) was effected. Age at surgery, age of epilepsy onset, sex, extent of lateral temporal resection, Full-Scale IQ (FSIQ), and preoperative naming scores were also examined as potential predictors of pre- versus postoperative naming change. RESULTS: Preoperative BNT and VN scores were significantly worse for HS+ than for HS- (BNT, p < 0.05; VN, p = 0.001). Postoperatively, BNT and VN scores significantly declined for HS- as compared with HS+ patients (p < 0.001). For individual risk, the 90th centile of reliable change index (RCI) was used. By this criterion, of the total sample, 39% evidenced decline on the BNT and 17% evidenced decline on the VN. Logistic regression analysis with backward elimination showed HS to be the only predictor of decline in BNT and HS and sex to be the only predictors of VN decline. Males were more at risk than females. Age, age at onset, extent of lateral resection, preoperative scores, and FSIQ were not predictors. Using age at onset as a proxy for HS+/HS- we calculated probabilities for naming decline for given onset age. CONCLUSIONS: Both preoperative and postoperative change in naming ability are associated with the pathological status of the hippocampus. The potential interpretations and implications of these findings are discussed.     

Apoptosis of endothelial cells. Contribution to the pathophysiology of atherosclerosis?

Endothelial cell injury is a key event in the pathogenesis of atherosclerosis. Importantly, endothelial cells in lesion-prone regions, where atherosclerotic lesions preferentially develop, are characterised by increased endothelial cell turn-over rates suggesting a mechanistic link between endothelial cell turn-over with preceding cell death and the susceptibility to atherosclerotic plaque development. The activation of the cellular suicide pathway leading to apoptosis of the endothelial cell may be an initial step in the development of atherosclerotic lesions. This hypothesis is supported by the finding that proatherosclerotic factors such as angiotensin II, oxidized low density lipoprotein, reactive oxygen species, glucose and inflammatory cytokines have all been shown to induce apoptosis of endothelial cells. In contrast, the known atheroprotective factors, such as oestrogen, nitric oxide or anti-oxidants, prevented endothelial cell apoptosis. Furthermore, laminar flow, which seems to be one of the most potent endogenous anti-atherosclerotic factor as illustrated by the focal nature of atherosclerotic lesion development in areas with turbulent or low blood flow, protects endothelial cell from apoptotic cell death. The present article summarizes the effects of pro and anti-atherosclerotic factors on endothelial cell apoptosis and provides insights into the underlying signalling events.