Microbial Hazards in Irrigation Water: Standards,Norms, and Testing to Manage Use of Water in Fresh Produce Primary Production

Accessibility to abundant sources of high‐quality water is integral to the production of safe and wholesome fresh produce. However, access to safe water is becoming increasingly difficult in many parts of the world, and this can lead to the production of fresh produce contaminated with pathogenic microorganisms, resulting in increased risk of human disease. Water, an important raw material in the fresh produce chain, is used in considerable amounts in many operations, including irrigation and application of pesticides and fertilizers, but also as a transport medium and for cooling and washing in postharvest practices. In several reported outbreaks related to uncooked fruit and vegetable products, water has been identified as a likely source of the outbreak. The present study, initiated by the ILSI Europe Emerging Microbiological Issues Task Force in collaboration with 8 other ILSI branches and support of WHO/FAO, was undertaken to review the status of, and provide suggestions for, consideration by different stakeholders on water and sanitation and its impact on food safety and public health. A limited number of guidelines and regulations on water quality for agricultural production are available, and many of them are still heavily based on microbial standards and (debated) parameters such as fecal coliforms. Data gaps have been identified with regard to baseline studies of microbial pathogens in water sources in many regions, the need for agreement on methods and microbial parameters to be used in assessing water quality, the fate of pathogens in water, and their transfer and persistence on irrigated/processed produce.     

Effect of superatmospheric oxygen packaging on sensorial quality,spoilage, and Listeria monocytogenes and Aeromonas caviae growth in fresh processed mixed salads

Atmospheres with O2 levels higher than 70 kPa have recently been suggested as an innovation to modified atmosphere packaging (MAP) for fresh processed vegetables to maintain sensory quality and safety. In the present work, mixed vegetable salad collected from a commercial processing plant and stored with the MAP technique was studied. Two gas mixtures were actively generated by using an initial O2 concentration of 95 kPa and combined with two plastic films. The low-barrier film permeability for O2 was 1,629 mlO2/m2 x 24 h x atm with 30 microm of thickness (Hyplast, Hoogstraten, Belgium) and the O2 permeability of the high-barrier film was 2 mlO2/m2 x 24h x atm with 150 microm of thickness (Euralpack, Wommelgen, Belgium) at 23 degrees C. As control, active conventional MAP with application of 3 to 5 kPa of O2 and 6 to 8 kPa of CO2 was used. Packaged salads were stored up to 8 days at 4 degrees C and at temperatures simulating chilled distribution chain conditions. Microbial safety and sensory quality, as well as the survival of inoculated Listeria monocytogenes and Aeromonas caviae, were monitored. The effect of superatmospheric O2 on the growth of aerobic microflora was variable. Under superatmospheric conditions, lactic acid bacteria and members of Enterobacteriaceae were inhibited. Nevertheless, growth of yeast and A. caviae seem to be stimulated by superatmospheric O2, whereas growth of psychrotrophic bacteria and L monocytogenes was not affected. The overall visual appearance (mainly color) of the mixed vegetable salads was better maintained and the shelf life prolonged when packaged under O2 concentrations greater than 50 kPa.     

FAMOUS: A Network Architecture for Delivering Multimedia Services to FAst MOving USers

When today’s commuters in the train or in a car want to access the Internet, they see themselves restricted to simple web surfing or e-mail. Interactive multimedia services, like online gaming or video conferencing are still unavailable to them, even with promising new technologies like UMTS or WiMAX. The impact of high bit rate multimedia traffic on the access network and aggregation network is an important topic, that has not been addressed in enough detail before. We designed a network architecture for offering these multimedia services to fast moving users. We refer to the overall network architecture as the FAMOUS network architecture, which consists of two parts: (i) an access network part which has to deal with large number of users, asking for a high bandwidth, while experiencing a high handoff frequency and (ii) an aggregation network part which has to deal with dynamic tunnels of very high bandwidth, while experiencing a low handoff frequency. In this paper, we detail the FAMOUS architecture, together with optimized handoff strategies, an optical switching architecture, a design methodology for dimensioning aggregations networks and automatic tunnel pre-configuration and activation. Moreover, performance results of these mentioned aspects will be presented.Filip De Greve was born in Gent, Belgium, in 1978. He received his Master of Science degree in Electrotechnical Engineering from Ghent University, Gent, Belgium in 2001. In 2002, he joined the Department of Information Technology of the Faculty of Applied Sciences, University of Ghent as a doctoral researcher. Besides specific Ethernet-related research topics, his current research interests are related to broadband communication networks and include design, routing and reliability of access and aggregation networks.Bart Lannoo was born in Torhout, Belgium, in 1979. He received his Master of Science degree in Electrotechnical Engineering from Ghent University, Ghent, Belgium in 2002. Since August 2002, he has been working with Department of Information Technology (INTEC) of the Faculty of Applied Sciences, Ghent University as a doctoral researcher. His current research interests are in optical access networks, including both fixed access networks (FTTx) and optical access for wireless communication.Liesbeth Peters received the degree in Electrotechnical Engineering from Ghent University, Belgium in 2001. Since August 2001, she has been working as a doctoral researcher with the Department of Information Technology of Ghent University, where she joined the Broadband Communications Networks Group. Since October 2002, she works there as a research assistant of the Fund for Scientific Research – Flanders (F.W.O.-V., Belgium). Her current research interests are in broadband wireless communication and the support of IP mobility in wired cum wireless networks.Tom Van Leeuwen was born in Gent, Belgium, in 1979. He received his masters degree in Computer Engineering from the Ghent University, Gent, Belgium in 2002. Since 2002, he has been working with Department of Information Technology of Ghent University (INTEC) as a doctoral researcher. In 2004 he received a PhD grant from the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen). His current research interests are in broadband wireless communication.Frederic Van Quickenborne (M. Sc. Degree in Electrotechnical Engineering, University of Ghent, Belgium, 2002) published different papers on the growing importance of ethernet in aggregation and core networks. Besides his interest in ethernet related topics (QoS, VLANs, xSTP), he is also involved in projects concerning video-streaming and is working on a Click-based ethernet testbed. This research is funded by a PhD grant from the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen), that he obtained in 2004.Didier Colle received a M.Sc. degree in electrotechnical engineering (option: communications) from the Ghent University in 1997. Since then, he has been working at the same university as researcher in the department of Information Technology (INTEC). He is part of the research group INTEC Broadband Communication Networks (IBCN) headed by Prof.: Piet Demeester. His research lead to a Ph.D. degree in February 2002. From January 2003 on, he was granted a postdoctoral scholarship from the “Instituut voor de aanmoediging van Innovatie door Wetenschap en Technologie in Vlaanderen (IWT-Vlaanderen)”. His research deals with design and planning of communication networks. His work is focussing on optical transport networks, to support the next-generation Internet. Up till now, he has actively been involved in three IST projects (LION, OPTIMIST and DAVID) and in the COST266 action. His work has been published in more than 40 scientific publications in international conferences and journals.Filip de Turck received his M.Sc. degree in Electronic Engineering from the Ghent University, Belgium, in June 1997. In May 2002, he obtained the Ph.D. degree in Electronic Engineering from the same university. From October 1997 to September 2001, Filip De Turck was research assistant with the Fund for Scientific Research-Flanders, Belgium (F.W.O.-V.). At the moment, he is a part-time professor and a post-doctoral fellow of the F.W.O.-V., affiliated with the Department of Information Technology of the Ghent University. Filip De Turck is author or co-author of approximately 80 papers published in international journals or in the proceedings of international conferences. His main research interests include scalable software architectures for telecommunication network and service management, performance evaluation and optimization of routing, admission control and traffic management in telecommunication systems.Ingrid Moerman was born in Gent, Belgium, in 1965. She received the degree in Electro-technical Engineering and the Ph.D degree from the Ghent University, Gent, Belgium in 1987 and 1992, respectively. Since 1987, she has been with the Interuniversity Micro-Electronics Centre (IMEC) at the Department of Information Technology (INTEC) of the Ghent University, where she conducted research in the field of optoelectronics. In 1997, she became a permanent member of the Research Staff at IMEC. Since 2000 she is part-time professor at the Ghent University. Since 2001 she has switched her research domain to broadband communication networks. She is currently involved in the research and education on broadband mobile & wireless communication networks and on multimedia over IP. She is author or co-author of more than 300 publications in the field of optoelectronics and communication networks.Mario Pickavet received an M.Sc. and Ph.D. degree in electrical engineering, specialized in telecommunications, from Ghent University in 1996 and 1999, respectively. Since 2000, he is professor at Ghent University where he is teaching telecommunication networks and algorithm design. His current research interests are related to broadband communication networks (WDM, IP, (G-)MPLS, OPS, OBS) and include design, long-term planning and routing of core and access networks. In this context, he is currently involved a.o. in the European IST projects “All-Optical Label Swapping Employing Optical Logic Gates in Network Nodes” (LASAGNE) and “Optical Networks: Towards Bandwidth Manageability and Cost Efficiency” (e-Photon/ONe) and in several national research projects. He has published about a hundred international publications, both in journals (e.g. IEEE JSAC, IEEE Comm. Mag., JLT) and in proceedings of conferences. He is one of the authors of the book ‘Network Recovery: Protection and Restoration of Optical, SONET-SDH, IP, and MPLS’.Bart Dhoedt received a degree in Engineering from the Ghent University in 1990. In September 1990, he joined the Department of Information Technology of the Faculty of Applied Sciences, University of Ghent. His research, addressing the use of micro-optics to realize parallel free space optical interconnects, resulted in a PhD degree in 1995. After a 2 year post-doc in opto-electronics, he became professor at the Faculty of Applied Sciences, Department of Information Technology. Since then, he is responsible for several courses on algorithms, programming and software development. His research interests are software engineering and mobile & wireless communications. Bart Dhoedt is author or co-author of approximately 70 papers published in international journals or in the proceedings of international conferences. His current research addresses software technologies for communication networks, peer-to-peer networks, mobile networks and active networks.Piet Demeester finished his PhD thesis at the Department of Information Technology (INTEC) at the Ghent University in 1988. At the same department he became group leader of the activities on Metal Organic Vapour Phase Epitaxial growth for optoelectronic components. In 1992 he started a new research group on Broadband Communication Networks. The research in this field resulted in already more than 300 publications. In this research domain he was and is a member of several programme committees of international conferences, such as: ICCCN, the International Conference on Telecommunication Systems, OFC, ICC, and ECOC. He was Chairman of DRCN’98. In 2001 he was chairman of the Technical Programme Committee ECOC’01. He was Guest Editor of three special issues of the IEEE Communications Magazine. He is also a member of the Editorial Board of the Journals “Optical Networks Magazine” and ldquo;Photonic Network Communications”. He was a member of several national and international PhD thesis commissions. Piet Demeester is a member of IEEE (Senior Member), ACM and KVIV. His current research interests include: multilayer networks, Quality of Service (QoS) in IP-networks, mobile networks, access networks, grid computing, distributed software, network and service management and applications (supported by FWO-Vlaanderen, the BOF of the Ghent University, the IWT and the European Commission). Piet Demeester is currently full-time professor at the Ghent University, where he is teaching courses in Communication Networks. He has also been teaching in different international courses.     

Optimal design of composite ChamberCore structures

An optimization procedure has been developed to uniquely and efficiently determine the “best” local geometry design of a new composite ChamberCore structure. This procedure is based on minimization of the total mass of a single composite ChamberCore subject to a set of design and stress constraints. The stress constraints are obtained in closed form based on the composite box-beam model for various composite lamination designs and loading conditions. The optimization problem statement is constructed and then solved using the VMCON optimization program, which is an iterative sequential quadratic programming (SQP) technique based on Powell's algorithm. The sensitivity of the solution of the optimal geometry to the values of parameters that characterize the structural durability and the failure mechanism is discussed.     

Emissions of maritime transport: A European reference system

Emissions from ships have recently received more attention since they have become a significant concern for air quality in harbours and port cities. This paper presents the methodology for a comprehensive maritime transport database of activity data, specific energy consumption, emission factors, and total emissions that have been developed within the European EX-TREMIS project. The model is built upon 3 modules: the fleet module, the transport activity module, and the emission module.The fleet module defines the ship categories, the loading capacities, and the engine characteristics of the different vessels by using EUROSTAT data, Sea Web Lloyd's database, and international literature. The transport activity module transforms total cargo handled (mainly based on EUROSTAT data and CEMT statistics) into ship-equivalents. These ship-equivalents are further transformed into ship-hours. The emission module calculates energy uses and CO₂, NO_X, SO₂, CO, HC, CH₄, NMHC, PM emissions from the resulting maritime activities. We have used technology based emission factors to take into account the technological evolution of vessels.To illustrate this new methodology, we present some results (emissions, fuel consumption and emission factors) for different countries. The overall methodology as well as the results and the country specific energy consumption and emission factors per ship type and size class can be extracted from the EX-TREMIS website (www.ex-tremis.eu). Our results contribute to more accurate estimates of emissions and air quality assessments in coastal cities and ports.     

Place Attachment Among Older Adults Living in Four Communities in Flanders,Belgium

There is strong evidence that age brings an increasing attachment to social and physical environments. However, the extent to which the experience of place attachment may vary between different types of locations remains underexplored in ageing research. Using a mixed-method approach consisting of two consecutive phases, this article aims to identify contextual factors that either promote or impede older people's attachment to place. In the first phase, quantitative data from the Belgian Ageing Studies were used to purposively select four municipalities: two with relatively strong and two with relatively weak place attachments among the older population. In the second, qualitative phase, two focus groups with local stakeholders and 20 semi-structured interviews with older residents were conducted in each of the four case study areas in order to explain and build on the quantitative results. The qualitative findings focus on two contextual factors that have been linked to place attachment: the physical–spatial environment and population turnover. The study identifies the various pathways between these factors and older people's attachments. The article concludes by discussing practical and policy issues raised by the research.     

SENSITIVITY ANALYSIS OF A ONE-DIMENSIONAL CONVECTION-DIFFUSION MODEL FOR SECONDARY SETTLING TANKS

One-dimensional models describing the flow and settling process in secondary settling tanks have great potential with respect to process control. Most of these models are based on a conservation equation that is discretized by dividing the settler into a fixed number of horizontal layers. In this article, the focus is on convection-diffusion models, which—in contrast to other one-dimensional models—ensure mesh-independent concentration profiles. The sensitivity of a prototype convection-diffusion model with respect to its parameters and the loading and operational conditions is studied by means of steady-state simulations. Based on the results, the importance of each of the model parameters is assessed. For each combination of parameter values, loading conditions, and operational variables considered in the study, the minimum number of layers required to obtain a practically mesh-independent concentration profile is determined on the basis of a newly developed objective criterion. This analysis leads to the identification of those factors having a large influence on the numerical behavior of the model.     

Children’s Application of Theory of Mind in Reasoning and Language

Many social situations require a mental model of the knowledge, beliefs, goals, and intentions of others: a Theory of Mind (ToM). If a person can reason about other people’s beliefs about his own beliefs or intentions, he is demonstrating second-order ToM reasoning. A standard task to test second-order ToM reasoning is the second-order false belief task. A different approach to investigating ToM reasoning is through its application in a strategic game. Another task that is believed to involve the application of second-order ToM is the comprehension of sentences that the hearer can only understand by considering the speaker’s alternatives. In this study we tested 40 children between 8 and 10 years old and 27 adult controls on (adaptations of) the three tasks mentioned above: the false belief task, a strategic game, and a sentence comprehension task. The results show interesting differences between adults and children, between the three tasks, and between this study and previous research.