Marine air pollution is a major contributor to seaports and coastal air pollution, and Israel has yet to seriously confront this issue. This study aimed to update previous marine air pollution estimations in Israel’s two major ports: Haifa and Ashdod. The objectives were to examine technical and regulatory measures to address the problem, to propose mitigation targets and to estimate their potential benefits. Based on a model of emission-calculations that relies on an updated ship-inventory data as well as real-time ships’ location and movement tools, the combined marine NOx, SOx and PM2.5 annual emissions in these ports were found to be 18,415, 15,128 and 1453 tons, respectively. These values are considerably higher than previous estimates, are comparable to the constant pollution emitted at ground level from a 1000-MW coal powered city power plant and are 3–20 times higher than the industrial and land transportation sectors in these cities. Relatively high nickel concentration in PM was found in Israel only relatively adjacent to the Haifa and Ashdod ports. Since high nickel concentration in PM is today mainly associated with marine air pollution, this finding supports the hypothesis that marine air pollution worsens the air quality in these cities. SOx and PM2.5 emissions can be reduced by 78% and 27%, respectively, if Israel enforces the revised International Convention for the Prevention of Pollution from Ships (MARPOL) Annex VI regulations in its territorial waters. While the latter step can achieve external benefits of NIS 518.4 million/year (EUR 132 million/year), additional mitigation actions and local regulations are suggested, focusing on NOx emissions but also on other pollutant criteria. Such actions can achieve further benefits of NIS 274.3 million/year (EUR 70 million/year). Achieving the suggested targets is challenging yet attainable, and their potential benefits will probably outweigh their costs.

In this work, an innovative sustainable spatial energy planning framework is developed on national scale for identifying and prioritizing appropriate, technically and economically feasible, environmentally sustainable as well as socially acceptable sites for the siting of large-scale onshore Wind Farms (WFs) and Photovoltaic Farms (PVFs) in Israel. The proposed holistic framework consists of distinctive steps allocated in two successive modules (the Planning and the Field Investigation module), and it covers all relevant dimensions of a sustainable siting analysis (economic, social, and environmental). It advances a collaborative and participatory planning approach by combining spatial planning tools (Geographic Information Systems (GIS)) and multi-criteria decision-making methods (e.g., Analytical Hierarchy Process (AHP)) with versatile participatory planning techniques in order to consider the opinion of three different participatory groups (public, experts, and renewable energy planners) within the site-selection processes. Moreover, it facilitates verification of GIS results by conducting appropriate field observations. Sites of high suitability, accepted by all participatory groups and field verified, form the final outcome of the proposed framework. The results illustrate the existence of high suitable sites for large-scale WFs' and PVFs' siting and, thus, the potential deployment of such projects towards the fulfillment of the Israeli energy targets in the near future.

One of the key methods for implementing the sustainability model in practice includes environmental vision and policy, goal setting, preference areas, and setting environmental research and development (ER&D) priorities. There are different ways to identify and prioritize the R&D of governments or international bodies, yet we have not found a comprehensive study or strategy regarding the framing and prioritization of ER&D at a national level. The aim of the study was to present a methodological approach, principles, and criteria for the prioritization of national ER&D. The study was initiated with a comprehensive literature review, including studies reported by a wide range of entities and countries, followed by the identification of eight principles to select ER&D priorities. Finally, each of the environmental issues was ranked in the frame of every principle, based on a quantitative criterion or criteria, considering global challenges, local needs, and capabilities.

Background Lag phase is a period of time with no growth that occurs when stationary phase bacteria are transferred to a fresh medium. Bacteria in lag phase seem inert: their biomass does not increase. The low number of cells and low metabolic activity make it difficult to study this phase. As a consequence, it has not been studied as thoroughly as other bacterial growth phases. However, lag phase has important implications for bacterial infections and food safety. We asked which, if any, genes are expressed in the lag phase of Escherichia coli , and what is their dynamic expression pattern. Results We developed an assay based on imaging flow cytometry of fluorescent reporter cells that overcomes the challenges inherent in studying lag phase. We distinguish between lag1 phase- in which there is no biomass growth, and lag2 phase- in which there is biomass growth but no cell division. We find that in lag1 phase, most promoters are not active, except for the enzymes that utilize the specific carbon source in the medium. These genes show promoter activities that increase exponentially with time, despite the fact that the cells do not measurably increase in size. An oxidative stress promoter, katG , is also active. When cells enter lag2 and begin to grow in size, they switch to a full growth program of promoter activity including ribosomal and metabolic genes. Conclusions The observed exponential increase in enzymes for the specific carbon source followed by an abrupt switch to production of general growth genes is a solution of an optimal control model, known as bang-bang control. The present approach contributes to the understanding of lag phase, the least studied of bacterial growth phases.

Bacteria regulate the assimilation of multiple nutrients to enable growth. How is balanced utilization achieved, despite fluctuations in the concentrations of the enzymes that make up the regulatory circuitry? Here we address this question by studying the nitrogen system of E. coli. A mechanism based on the avidity of a bifunctional enzyme, adenylyltransferase (AT/AR), to its multimeric substrate, glutamine synthetase, is proposed to maintain a robust ratio between two key metabolites, glutamine and α-ketoglutarate. This ratio is predicted to be insensitive to variations in protein levels of the core circuit and to the rate of nitrogen utilization. We find using mass spectrometry that the metabolite ratio is robust to variations in protein levels and that this robustness depends on the bifunctional enzyme. Moreover, robustness carries through to the bacteria growth rate. Interrupting avidity by adding a monofunctional AT/AR mutant to the native system abolishes robustness, as predicted by the proposed mechanism.

BACKGROUND:Gene regulation networks are made of recurring regulatory patterns, called network motifs. One of the most common network motifs is negative auto-regulation, in which a transcription factor represses its own production. Negative auto-regulation has several potential functions: it can shorten the response time (time to reach halfway to steady-state), stabilize expression against noise, and linearize the gene's input-output response curve. This latter function of negative auto-regulation, which increases the range of input signals over which downstream genes respond, has been studied by theory and synthetic gene circuits. Here we ask whether negative auto-regulation preserves this function also in the context of a natural system, where it is embedded within many additional interactions. To address this, we studied the negative auto-regulation motif in the arabinose utilization system of Escherichia coli, in which negative auto-regulation is part of a complex regulatory network.RESULTS:We find that when negative auto-regulation is disrupted by placing the regulator araC under constitutive expression, the input dynamic range of the arabinose system is reduced by 10-fold. The apparent Hill coefficient of the induction curve changes from about n = 1 with negative auto-regulation, to about n = 2 when it is disrupted. We present a mathematical model that describes how negative auto-regulation can increase input dynamic-range, by coupling the transcription factor protein level to the input signal.CONCLUSIONS:Here we demonstrate that the negative auto-regulation motif in the native arabinose system of Escherichia coli increases the range of arabinose signals over which the system can respond. In this way, negative auto-regulation may help to increase the input dynamic-range while maintaining the specificity of cooperative regulatory systems. This function may contribute to explaining the common occurrence of negative auto-regulation in biological systems.

Short Abstract — Bacteria simultaneously regulate the assimilation of multiple nutrients to enable optimized growth. How this precise balance is maintained, despite fluctuations in metabolic sources and sinks in the cell, and variations in concentrations of enzymes that make up the regulatory circuits? Here we address this by studying the nitrogen assimilation system of E. coli. A novel mechanism which is based on avidity of a bifunctional enzyme to its multimeric substrate is shown to provide a robust balance between carbon and nitrogen pools in the cell. We find experimentally that a robust ratio between the two pools is maintained and that this robustness carries through to the cells growth rate. coli uses a fascinating system to regulate nitrogen assimilation. The key enzyme in this system, glutamine synthetase (GS), produces glutamine from glutamate and ammonia (1). GS has an elaborate control mechanism with several unusual biochemical features. First, GS is active as a dodecamer made of 12 identical monomers. The activity of GS is determined by a reversible covalent modification: each monomer can be either adenylated or unadenylated, with adenylation inactivating the monomer's activity. The total activity of GS is the sum of its active monomers, without discernable cooperative effects (2). A second feature of this system is that the modification of GS is carried out by a bifunctional enzyme that catalyzes two opposing reactions. This enzyme, called adenylyl- transferase/adenylyl-removing enzyme, AT/AR, both adds and removes the adenyl modification of GS, using two distinct domains (3). The rates of these opposing reactions depend on two inputs: glutamine and the TCA-cycle metabolite α-ketoglutarate, which is the carbon backbone for glutamate and glutamine (4). By responding to both glutamine and its carbon backbone, α- ketoglutarate, the nitrogen system effectively senses the ratio between nitrogen and carbon: nitrogen is represented by glutamine and carbon by the TCA metabolite α- ketoglutarate. While the ratio of glutamine to α-ketoglutarate varies dramatically in response to nitrogen limitation, this ratio is remarkably steady under other conditions, such as