A SURVEY ON INSTITUTIONAL USERS OF SHELL EGGS AND EGG PRODUCTS IN FLANDERS

A survey assessed the handling of shell eggs and processed eggs from purchase until serving to potentially vulnerable people in care homes, acute hospitals, handicapped institutions, and crèches (i.e. nurseries). In 94% of the institutions shell eggs are consumed at a weekly average of 1.1 ± 0.3 eggs for each person. In 52% of the institutions egg products are used. The shell eggs are held on average at 6.4C for 1–2 weeks. The questionnaire listed a series of egg dishes, which were classified afterwards in three risk categories. Of the high-risk dishes, shell eggs are particularly used for addition to mashed potatoes, for preparing soft-boiled eggs and eggs sunny-side-up and for inclusion in hot sauces. Of the medium-risk dishes, shell eggs are used for preparing scrambled eggs and omelets. When egg products are bought next to shell eggs, relatively less high-risk dishes and more low-risk dishes on the total dishes were made from shell eggs. Thus, egg products are purchased on a rational base. The distribution of storage temperature, storage time and preparation frequency of high-risk meals were combined using a Monte Carlo resampling technique, which indicated that the majority of the samples (98.5%) fell into a low-hazard category.     

A MICROBIOLOGICAL SAFETY CONSUMER SURVEY ON THE HOUSEHOLD USE OF EGGS IN BELGIUM

A survey of parents of higher education college students assessed the purchasing behavior, storage conditions and consumption of hen eggs in the household, to quantify microbiological unsafe handling. Analysis of the questionnaires indicates an average consumption of 6.4 eggs per month, which are kept at an average temperature of 9.7C for 2 weeks. An additional spot check showed that the interviewees probably underestimate the keeping temperature. The questionnaire also listed a series of egg dishes, which were afterwards categorized according to risk. The distributions of storage temperature, keeping time and type of dish were combined using a Monte Carlo resampling technique, which resulted in a hazard distribution. This distribution showed that the majority of the samples (98.2%) fell into a low hazard category.     

A highly reliable and budget-friendly Peltier-cooled camera for biological fluorescence imaging microscopy

The SAC8.5, a low-cost Peltier-cooled black and white 8-bit CCD camera for astronomy, was evaluated for its use in imaging microscopy. Two camera–microscope configurations were used: an epifluorescence microscope (Nikon Eclipse TE2000-U) and a bottom port laser scanning confocal microscope system (Zeiss LSCM 510 META). Main advantages of the CCD camera over the currently used photomultiplier detection in the scanning setup are fast image capturing, stable background, an improved signal-to-noise ratio and good linearity. Based on DAPI-labelled Chinese Hamster Ovarian cells, the signal-to-noise ratio was estimated to be 4 times higher with respect to the currently used confocal photomultiplier detector. A linear relationship between the fluorescence signal and the FITC-inulin concentrations ranging from 0.05 to 1.8 mg mL⁻¹ could be established. With the SAC8.5 CCD camera and using DAPI, calcein-AM and propidium iodide we could also distinguish between viable, apoptotic and necrotic cells: exposure to CdCl₂ caused necrosis in A6 cells. Additional examples include the observation of wire-like mitochondrial networks in Mito Tracker Green-loaded Madin–Darby canine kidney cells. Furthermore, it is straightforward to interface the SAC8.5 with automated shutters to prevent rapid fluorophore photobleaching via easy to use astrovideo software. In this study, we demonstrate that the SAC8.5 black and white CCD camera is an easy-to-implement and cost-conscious addition to quantitative fluorescence microfluorimetry on living tissues and is suitable for teaching laboratories.     

A modular translation from defeasible nets to defeasible logics

Abstract

The sceptical inheritance nets introduced in Horty et al. [Proceedings of AAAI-87 (1987):358-363] are translated into a version of Nute's defeasible logic. Moreover this translation is modular in the sense of Thomason and Horty [Non-Monotonic Reasoning. Springer-Verlag (1989):234]. Apart from the importance of relating two nonmonotonic reasoning formalisms, this result shows that the reasoning mechanisms underlying defeasible logic and defeasible nets are the same. Yet they were invented independently and set in totally different contexts. This is perhaps some evidence that the underlying nonmonotonic reasoning mechanism is mainly correct. We also observe that since defeasible logics can contain both absolute and defeasible rules, they provided a uniform setting for considering nets which contain both strict and defeasible arcs.     

Extending the μLog Framework with Local and Conditional Blackboard Operations

This paper discusses two extensions of the kernel μLog framework presented by Jacquet and De Bosschere (1994): local blackboards and conditional access primitives. The former are needed to alleviate the blackboard communication bottleneck and to solve message naming conflicts whereas the latter improve the message selection power of pattern matching or unification. We propose a syntax for both extensions, give their operational semantics, provide a declarative semantics and prove the soundness and completeness properties in our setting. Moreover,we discuss a specialization of this framework using Prolog astarget language. An implementation is presented and the applicability of the proposed framework and language is argued through the coding of a reactive system.     

Toward a Strategy for Teaching Engineering Design

Design is behavior. Therefore, it can best be understood by means of behavioral theory and must be taught in a way consistent with the theory of behavior modification. This simple fact appears to have been overlooked by most, if not all, engineering educators who teach design courses or write textbooks on engineering design. This article examines this thesis and its relationship to engineering heuristics by considering specific examples taken from current practice in engineering design education.