Use of transgenic GFP reporter strains of the nematode Caenorhabditis elegans to investigate the patterns of stress responses induced by pesticides and by organic extracts from agricultural soils

As a free-living nematode, C. elegans is exposed to various pesticides used in agriculture, as well as to persistent organic residues which may contaminate the soil for long periods. Following on from our previous study of metal effects on 24 GFP-reporter strains representing four different stress-response pathways in C. elegans (Anbalagan et al. 2012), we now present parallel data on the responses of these same strains to several commonly used pesticides. Some of these, like dichlorvos, induced multiple stress genes in a concentration-dependent manner. Unusually, endosulfan induced only one gene (cyp-34A9) to very high levels (8-10-fold) even at the lowest test concentration, with a clear plateau at higher doses. Other pesticides, like diuron, did not alter reporter gene expression detectably even at the highest test concentration attainable, while others (such as glyphosate) did so only at very high concentrations. We have also used five responsive GFP reporters to investigate the toxicity of soil pore water from two agricultural sites in south-east Spain, designated P74 (used for cauliflower production, but significantly metal contaminated) and P73 (used for growing lettuce, but with only background levels of metals). Both soil pore water samples induced all five test genes to varying extents, yet artificial mixtures containing all major metals present had essentially no effect on these same transgenes. Soluble organic contaminants present in the pore water were extracted with acetone and dichloromethane, then after evaporation of the solvents, the organic residues were redissolved in ultrapure water to reconstitute the soluble organic components of the original soil pore water. These organic extracts induced transgene expression at similar or higher levels than the original pore water. Addition of the corresponding metal mixtures had either no effect, or reduced transgene expression towards the levels seen with soil pore water only. We conclude that the main toxicants present in these soil pore water samples are organic rather than metallic in nature. Organic extracts from a control standard soil (Lufa 2.2) had negligible effects on expression of these genes, and similarly several pesticides had little effect on the expression of a constitutive myo-3::GFP transgene. Both the P73 and P74 sites have been treated regularly with (undisclosed) pesticides, as permitted under EU regulations, though other (e.g. industrial) organic residues may also be present

Transgenic nematodes as biosensors for metal stress in soil pore water samples

Caenorhabditis elegans strains carrying stress-reporter green fluorescent protein transgenes were used to explore patterns of response to metals. Multiple stress pathways were induced at high doses by most metals tested, including members of the heat shock, oxidative stress, metallothionein (mtl) and xenobiotic response gene families. A mathematical model (to be published separately) of the gene regulatory circuit controlling mtl production predicted that chemically similar divalent metals (classic inducers) should show additive effects on mtl gene induction, whereas chemically dissimilar metals should show interference. These predictions were verified experimentally; thus cadmium and mercury showed additive effects, whereas ferric iron (a weak inducer) significantly reduced the effect of mercury. We applied a similar battery of tests to diluted samples of soil pore water extracted centrifugally after mixing 20% w/w ultrapure water with air-dried soil from an abandoned lead/zinc mine in the Murcia region of Spain. In addition, metal contents of both soil and soil pore water were determined by ICP-MS, and simplified mixtures of soluble metal salts were tested at equivalent final concentrations. The effects of extracted soil pore water (after tenfold dilution) were closely mimicked by mixtures of its principal component ions, and even by the single most prevalent contaminant (zinc) alone, though other metals modulated its effects both positively and negatively. In general, mixtures containing similar (divalent) metal ions exhibited mainly additive effects, whereas admixture of dissimilar (e.g. trivalent) ions often resulted in interference, reducing overall levels of stress-gene induction. These findings were also consistent with model predictions

Data collection on Shipper's Preferences Using Simulation Games: A Synchromodality Case Study

The development of new more efficient freight transportation services requires in depth understanding of the engaged stakeholders behavior. Simulation Games (SG) have been used to study decisions and raise awareness over complex transport problems. This paper investigates the possibility of applying a simulation game as an innovative data collection tool for choices related to freight transport. Games sessions were organised with Dutch logistics managers and data on their choices for synchromodal services were collected. Model results revealed reliability, costs and reduced work load as key factors making shippers to opt for more synchromodal services. </p

Application of aggregate container terminal data for the development of time-of-day models predicting truck arrivals

Workload forecasting related to truck arrivals is of essential importance not only for optimal resource allocation but also for encountering delays and bottlenecks in the landside operations of terminals. In order to increase their efficiency, some ports have tried to implement various methods such as Truck Appointment Systems (TAS) but, in general, information on the arrival times of trucks to pick up containers remains unreliable and scarce. This paper sought to develop pick-up time-of-day models for import containers using data easily retrieved from Terminal Operating Systems (TOS). Model results indicate that the receiver of goods and container characteristics are among the main factors affecting pick-up time-of-day. Differentiation is observed between the different days of the week. The developed Time-Of- Day (TOD) models can be used to calculate the probability of drayage truck arrival times. The application of the proposed methodology proves helpful when reliable information of truck arrivals is unavailable, and can also be used alongside TAS implementation to assist terminal operators.Transport and Logistic

Data collection on Shipper's Preferences Using Simulation Games: A Synchromodality Case Study

The development of new more efficient freight transportation services requires in depth understanding of the engaged stakeholders behavior. Simulation Games (SG) have been used to study decisions and raise awareness over complex transport problems. This paper investigates the possibility of applying a simulation game as an innovative data collection tool for choices related to freight transport. Games sessions were organised with Dutch logistics managers and data on their choices for synchromodal services were collected. Model results revealed reliability, costs and reduced work load as key factors making shippers to opt for more synchromodal services. Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Transport and PlanningTransport and Logistic

A disaggregate model of passenger-freight matching in crowdshipping services

Crowdshipping (CS) is an emerging form of freight transport that is expected to reduce the externalities of urban freight transport. The supply of CS services originates from people with an intention to travel, who can choose to engage in a parcel delivery service as incidental carrier. The popular expectation is that this consolidation of freight and passenger trips could save freight trips and thus alleviate urban transport congestion and environmental pollution. A key challenge in the prediction of CS service volumes and impacts, however, is to match existing service demand and supply. This has not yet been addressed in the literature with models that give an empirically realistic representation of individual decision-making. We approach this problem using a disaggregate activity-based models for urban passenger transport and freight transport. Allocation of parcels to travellers is done based on a simulated random utility discrete choice model. We present a first case study for the city of The Hague, The Netherlands, to illustrate empirically the model. Our findings suggest that CS could result in increased CO2 emissions and total vehicle distances travelled

Unique and contrasting effects of light and temperature cues on plant transcriptional programs

Plants have adapted to tolerate and survive constantly changing environmental conditions by reprogramming gene expression in response to stress or to drive developmental transitions. Among the many signals that plants perceive, light and temperature are of particular interest due to their intensely fluctuating nature which is combined with a long-term seasonal trend. Whereas specific receptors are key in the light-sensing mechanism, the identity of plant thermosensors for high and low temperatures remains far from fully addressed. This review aims at discussing common as well as divergent characteristics of gene expression regulation in plants, controlled by light and temperature. Light and temperature signaling control the abundance of specific transcription factors, as well as the dynamics of co-transcriptional processes such as RNA polymerase elongation rate and alternative splicing patterns. Additionally, sensing both types of cues modulates gene expression by altering the chromatin landscape and through the induction of long non-coding RNAs (lncRNAs). However, while light sensing is channeled through dedicated receptors, temperature can broadly affect chemical reactions inside plant cells. Thus, direct thermal modifications of the transcriptional machinery add another level of complexity to plant transcriptional regulation. Besides the rapid transcriptome changes that follow perception of environmental signals, plant developmental transitions and acquisition of stress tolerance depend on long-term maintenance of transcriptional states (active or silenced genes). Thus, the rapid transcriptional response to the signal (Phase I) can be distinguished from the long-term memory of the acquired transcriptional state (Phase II - remembering the signal). In this review we discuss recent advances in light and temperature signal perception, integration and memory in Arabidopsis thaliana, focusing on transcriptional regulation and highlighting the contrasting and unique features of each type of cue in the process

Simulation Games to Study Transportation Issues and Solutions: Studies on Synchromodality

In this paper we discuss the application of simulation gaming to study the behavior and decision making of stakeholders when confronted with complex transportation problems. The problem we tackle is synchromodal transportation. Synchromodality requires the vertical and horizontal collaboration of stakeholders in all the levels of decision making. To facilitate this, we develop four games designed in a way that meets the needs of decision makers in each level. We present both board and digital games and the results from the first gaming sessions with Dutch supply chain and logistics professionals.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Transport and LogisticsSupport Multi Actor SystemsPolicy AnalysisTransport and Plannin

Fostering sustainable transportation operations through corridor management: A simulation gaming approach

Synchromodality is described as a network of well-synchronised and interconnected transportation modes. One of the most important advantages of synchromodality is the development of a sustainable transportation system. Given the numerous stakeholders and network interdependencies within freight transport corridors, achieving efficient coordination and management is complex. In this paper, we regard information exchange as one of the main enablers of collaboration between the infrastructure managers. We developed a digital single-player simulation game called “Modal Manager” comprising logistic service providers and infrastructure managers. Each player takes over the role of an infrastructure manager who must use information provision as a tool to control flows in a network where various planned and unplanned disruptions occur. We include the game in a session where participants are able to interact with the game and with each other. The first gameplay session with Dutch experts revealed that infrastructure managers perceive synchromodality as a way to cope with disruptions more efficiently. On the other hand, the concept of synchromodal corridor management is ambiguous and various legal and governance barriers exist that hinder its implementation.Policy AnalysisTransport and LogisticsTransport and Plannin

A disaggregate model of passenger-freight matching in crowdshipping services

Crowdshipping (CS) is an emerging form of freight transport that is expected to reduce the externalities of urban freight transport. The supply of CS services originates from people with an intention to travel, who can choose to engage in a parcel delivery service as incidental carrier. The popular expectation is that this consolidation of freight and passenger trips could save freight trips and thus alleviate urban transport congestion and environmental pollution. A key challenge in the prediction of CS service volumes and impacts, however, is to match existing service demand and supply. This has not yet been addressed in the literature with models that give an empirically realistic representation of individual decision-making. We approach this problem using a disaggregate activity-based models for urban passenger transport and freight transport. Allocation of parcels to travellers is done based on a simulated random utility discrete choice model. We present a first case study for the city of The Hague, The Netherlands, to illustrate empirically the model. Our findings suggest that CS could result in increased CO2 emissions and total vehicle distances travelled.Transport and PlanningTransport and Logistic