Computing distance transformations in convex and non-convex domains

It is shown that the well known two-pass sequential local transformation algorithm for computing a distance transformation in rectangular domains may fail in some convex integer domains, but that a four-pass algorithm is sufficient in all two-dimensional convex domains. For non-convex domains the number of passes necessary is shown to be generally greater. Two propagation algorithms for computing the distance transformation are described and shown theoretically and experimentally to be computationally more efficient than the sequential local transformation algorithm in non-convex domains of complex shape. The relationship of the distance transformation in non-convex domains to some more general transformations is explored.     

Paper remote: an augmented television guide and remote control

The television (TV) is one of the most common entertainment devices in homes. Searching and finding TV programs is a common task and using TV guides is one way of performing this. This paper presents three studies that are focused on examining audiences’ TV habits and TV guide usage, evaluating a new concept based on linking paper and pen with TV technology, and studying the audiences’ attitudes toward and anticipated interest in the future guide. The results of our first study emphasize the value of using paper based TV guides and also identify the deficiencies. We also found indications that the advantages and disadvantages of paper-based TV guides are related to the physical properties of paper. Thus, we suggest a solution that uses digital pen and paper technology to offer a new interaction method for TV. A research system “Paper Remote”, is developed and used in the two subsequent studies. Viewers tick designated areas on the paper-based guide to perform actions such as channel switching. However, this solution is not a substitute for the remote control device. We argue that these user studies on linking digital paper to the TV for everyday information navigation illuminate the possibilities of providing innovative solutions also for home information systems also.     

New CAMAC based data acquisition and beam control system for Lund nuclear microprobe

A new CAMAC based data acquisition system has been installed at the Lund Nuclear Microprobe facility. This paper reports on the development and present status of the data acquisition system. The system is a true multiparameter CAMAC based system with fast Fera bus readout and in crate memory buffer. The user interface is based on Sparrow Kmax software for a Power Macintosh platform. The system read out and tag the event data with position on-line, which make fast on-line monitoring of spectra or element maps possible.Simultaneously, all data can be saved event by event for off-line analysis. The beam scanning part is software controlled through a timed D/A converter, this allows fast scanning of the beam. With a CCD-camera and video card the area to be analysed could be defined directly from the image, and the sample position can be moved. Any kind of irregular scan patterns could be defined.     

Low density lipoprotein catabolism is enhanced by the cleaved form of alpha-1-antitrypsin

The frequent occurrence of hypocholesterolaemia following inflammatory processes is well known but unexplained. Elevated plasma levels of serine proteinase inhibitors (serpins) and their complexes with target enzymes have been demonstrated in inflammatory, malignant and infectious diseases which are also often accompanied by low plasma cholesterol levels. Under inflammatory conditions, uncomplexed, but cleaved inactive serpins arising from slow deacylation of the serpin-proteinase complex may be present in the circulation. To determine the influence of native and cleaved forms of serpins, such as alpha-1-antitrypsin (AAT), on lipoprotein metabolism, we investigated the effect of these forms on low density lipoprotein (LDL) catabolism in human HepG2 cell line. We have found that the cleaved form of AAT in concentrations from 125 to 2000 nmol l-1 stimulates LDL binding to the HepG2 cells, by up to 49% with a subsequent increase in LDL uptake and degradation of up to 79 and 65% respectively. Native AAT was also found to increase LDL binding and internalization by 20-25%, independently of the amount of AAT added, an effect most probably due to the cleaved form of AAT produced by local proteolysis of native AAT incubated in the cell culture. Moreover we have shown that the cleaved form of AAT interacts with LDL in vitro, and that such an interaction abolishes AAT ability to stimulate LDL binding and internalization. This study for the first time describes the ability of the cleaved form of AAT to stimulate LDL binding and internalization in HepG2 cell culture, and provides evidence that hypocholesterolaemia occurring during inflammatory processes may be mediated by cleaved forms of serpins.     

A Mass Transport Model for Drying Wood under Isothermal Conditions

Mass transport in wood during drying can have different mechanisms at different periods of drying. Depending on the current moisture content (MC) and the structure of the wood, the driving forces for the mass transport are essentially different. Above the fiber saturation point (FSP), the lumens are partially saturated and the transport of liquid (free) water occurs as a consequence of capillary action. On the other hand, below the FSP, bound water within the cell walls is conveyed by diffusion, and water vapor in the lumens moves under influence of pressures gradient. Based on these considerations, a unified model is presented that takes into account the transport of the different moisture phases. Simulation of the drying of a Norway spruce sample at 50°C from about 135 to 7% MC is carried out using the finite element method (FEM). Comparison between the simulated average MC and the experimental observations obtained from X-ray computed tomography (CT) shows reasonable agreement. Possible simplifications in the model are briefly discussed as well as some aspects of the numerical implementation. Finally, the influence of absolute permeability on the average MC is studied.     

Estrogenic personal care products in a greywater reuse system.

The occurrence and fate of parabens in a greywater system was assessed. The potential for removal of residual paraben concentrations in effluent greywater with chlorine dioxide was also investigated. The influent to the greywater plant was characterised by considerable variation, with concentrations from below the detection limit to 40 microg/L and the five commonly used parabens in consumer products were frequently detected. After the biological treatment only two paraben were detected with concentration from 65-120 ng/L. Chlorine dioxide treatment of the biologically treated effluent with dosages down to 0.75 mg/L resulted in more than 97% reduction of all parabens. Formation of the by-product chloroform was insignificant from the chlorine dioxide treatment.     

Implant exudate leucocyte response to anti-inflammatory drug treatment

Implantation of artificial materials elicits a local inflammatory response. In this study a chamber model technique, allowing sampling of the inflammatory exudate for further analysis in vitro, was used. Male Sprague-Dawley rats were injected daily with two different anti-inflammatory drugs, betamethasone and indomethacin, and the local cellular response was compared with a control group. The retrieved exudate was evaluated with respect to the number of leucocytes, cell viability, differential counts and serum-opsonized zymosan stimulated chemiluminescence (CL). In all groups the majority of cells were polymorphonuclear granulocytes (PMNGs). Betamethasone and high-dose indomethacin (1.92 mg kg^-1 body weight day^-1) treatment caused a marked reduction in the number of accumulated leucocytes 6 days after implantation. A substantial inhibition of the CL response was observed 6 days after treatment with betamethasone (4.23 mg kg^-1 body weight day^-1). An increased CL responsiveness was observed after 24 h with low-dose indomethacin (0.03 mg kg^-1 body weight day^-1) and after 6 days with high-dose indomethacin (1.92 mg kg^-1 body weight day^-1) treatment. In summary, depending on the anti-inflammatory drug treatment, dose and time after implant surgery, either an inhibition or stimulation of leucocyte accumulation and activation was observed. This study shows the possibilities of sampling the inflammatory exudate adjacent to a biomaterial implanted in vivo. This chamber model may be useful for the analysis of the inflammatory reaction around an implanted biomaterial during pharmacological treatment.     

Robust stability of systems with delayed feedback

Some issues in the stability of differential delay systems in the linear and the nonlinear case are investigated. In particular, sufficient robustness conditions are derived under which a system remains stable, independent of the length of the delay(s). Applications in the design of delayed feedback systems are given. Two approaches are presented, one based on Lyapunov theory, the other on a transformation to Jordan form. In the former, sufficient conditions are obtained in the form of certain Riccati-type equations.     

A classification of predictive-reactive project scheduling procedures

The vast majority of the project scheduling research efforts over the past several years have concentrated on the development of workable predictive baseline schedules, assuming complete information and a static and deterministic environment. During execution, however, a project may be subject to numerous schedule disruptions. Proactive-reactive project scheduling procedures try to cope with these disruptions through the combination of a proactive scheduling procedure for generating predictive baseline schedules that are hopefully robust in that they incorporate safety time to absorb anticipated disruptions with a reactive procedure that is invoked when a schedule breakage occurs during project execution. In this paper we discuss the results obtained by a large experimental design set up to evaluate several predictive-reactive resource-constrained project scheduling procedures under the composite objective of maximizing both the schedule stability and the timely project completion probability.     

Enzymatic biodiesel production: Technical and economical considerations

It is well documented in the literature that enzymatic processing of oils and fats for biodiesel is technically feasible. However, with very few exceptions, enzyme technology is not currently used in commercial‐scale biodiesel production. This is mainly due to non‐optimized process design and a lack of available cost‐effective enzymes. The technology to re‐use enzymes has typically proven insufficient for the processes to be competitive. However, literature data documenting the productivity of enzymatic biodiesel together with the development of new immobilization technology indicates that enzyme catalysts can become cost effective compared to chemical processing. This work reviews the enzymatic processing of oils and fats into biodiesel with focus on process design and economy.