Intake of polychlorinated biphenyls (PCB) from the Finnish diet

Concentrations of seven single PCB indicator congeners were measured in 99 food samples. These concentrations were converted into a total PCB content and used for estimating total PCB intake among Finns. The average intake from food is 15 g/day or 0,25 /kg body weight per day, which showed no change during the late 1980s. Approximately half of the intake comes from fish. The composition of the PCB mixture varies a lot in different sample types, which emphasizes the importance of single compound determination.

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Ermittlung der mit der finnischen Nahrung aufgenommenen polychlorierten Biphenyle (PCB)

Zusammenfassung An 99 Lebensmittelproben wurden die Konzentrationen von sieben einzelnen PCB-Indikatorverbindungen gemessen und in Gesamt-PCB-Konzentrationen umgerechnet, die dann zur Schätzung der vom finnischen Verbraucher aufgenommenen PCB-Menge dienten. Die durchschnittliche Aufnahme mit der Nahrung betrug 15 g pro Tag oder 0,25 g pro Tag und kg Körpergewicht. In der zweiten Hälfte der 80er Jahre ist keine Veränderung in der Aufnahme festzustellen. Etwa die Hälfte der Menge wird beim Verzehr von Fisch aufgenommen. Die Zusammensetzung des PCB-Gemisches zeigt von Probetyp zu Probetyp starke Schwankungen, was die Notwendigkeit der Bestimmung der Einzelverbindungen unterstreicht.

     

Increased kidney xanthine oxidoreductase activity in salt-induced experimental hypertension

OBJECTIVES: To assess the efficacy and safety of low molecular weight heparin (LMWH) as deep venous thrombosis (DVT) prophylaxis following total knee arthroplasty. DATA SOURCES: Medline 1986 to June 1997, Embase, and manufacturers were used to identify randomized controlled trials. REVIEW METHODS: Trials included were randomized studies of LMWH with routine radiological screening for DVT. Placebo or active controls were included. Two reviewers independently screened trials for inclusion, and assessed their quality. Pooled relative risk estimates of DVT and proximal DVT rates were calculated using a DerSimonian and Laird random effects model. Sensitivity of the results to the type of control used and the quality of the trial was assessed. RESULTS: The relative risk of DVT for a patient given LMWH is 0.73 (95% CI 0.66 to 0.80) when compared with patients treated with adjusted dose heparin or warfarin controls. The relative risk for proximal DVT is 0.58 (95% CI 0.38 to 0.90). The relative risk of pulmonary emboli in the LMWH group was 0.55 (95% C.I. 0.20 to 1.57). No excess of bleeding was recorded in the LMWH group. CONCLUSIONS: Low molecular weight heparin is more efficacious than either adjusted dose heparin or adjusted dose warfarin, when used to prevent DVT and proximal DVT following total knee arthroplasty.     

Dry polyacrylamide batch method for studying drug protein binding

The validity of a new technique for studying drug protein binding is tested. By this gel diffusion or batch method using dry polyacrylamide, sulfadiazine and sulfafurazole are bound by human plasma proteins to the same extent as reported by other authors with different techniques. The binding of warfarin to fresh human plasma was quantitatively less than expected. This might be due to the possibility that other plasma constituents of non-fasted test persons displace warfarin from protein binding sites, since it is bound more in buffer solutions containing physiological concentrations of human albumin. Phenylbutazone displaced warfarin from its binding sites in diluted human serum albumin concentrations. Quinidine was found to be adsorbed by the otherwise inert polyacrylamide gel and the method is therefore not applicable to quinidine binding studies.     

Head Orientation Prediction: Delta Quaternions Versus Quaternions

Display lag in simulation environments with helmet-mounted displays causes a loss of immersion that degrades the value of virtual/augmented reality training simulators. Simulators use predictive tracking to compensate for display lag, preparing display updates based on the anticipated head motion. This paper proposes a new method for predicting head orientation using a delta quaternion (DQ)-based extended Kalman filter (EKF) and compares the performance to a quaternion EKF. The proposed framework operates on the change in quaternion between consecutive data frames (the DQ), which avoids the heavy computational burden of the quaternion motion equation. Head velocity is estimated from the DQ by an EKF and then used to predict future head orientation. We have tested the new framework with captured head motion data and compared it with the computationally expensive quaternion filter. Experimental results indicate that the proposed DQ method provides the accuracy of the quaternion method without the heavy computational burden.     

Collaborative context determination to support mobile terminal applications

Mobile devices, together with their users, are constantly moving from one situation to another. To adapt applications to these changing contexts, the devices must have ways to recognize the contexts. There are various sources for context information: sensors, tags, positioning systems, to name a few. The raw signals from these sources are translated into higher-level interpretations of the situation. Unfortunately, such data is often unreliable and constantly changing. We seek to improve the reliability of context recognition through an analogy to human behavior. Where multiple devices are around, they can jointly negotiate on a suitable context and behave accordingly. This approach is becoming particularly attractive with the multitude of personal devices on the market. We present a collaborative context determination scheme, suggest examples of potential applications of such collaborative behavior, and raise issues of context recognition, context communication, and network requirements.