653 research outputs found
Attribution of pollution generation to local private and public demands in a small open economy: results from a SAM-based neo-classical linear attribution system for Scotland
For the construction of environmental accounts, Input Output (IO) systems have a number of clear advantages. First IO is an internally consistency, rigorous accounting framework. Second, the characteristics of IO systems are well known. Third, IO systems focus on the link between intermediate and final demands, and can attribute the indirect, intermediate use of commodities to elements of final demand. However, there are concerns over the degree of appropriateness of the standard IO attribution approaches (McGregor et al, 2001a). If standard Type I output-pollution multiplier, especially in the case of a very open economy such as Scotland, responsibility for much pollution can be attributed to external sources of demand. Furthermore, when Type II output-pollution multipliers are utilised, local private consumption virtually disappears as a pollution source. This seems to be at variance with the common environmental approach, which would wish to place domestic consumption at the centre of pollution attribution
Three and Four Region Multi-sector Linear Modelling Using UK Data : Some Preliminary Results
Scotland and Wales have relatively up-to-date, independently generated, IO tables. These can be separated out from a UK national IO table to construct an inter-regional table. We therefore undertake the detailed analysis at this three-region (Scotland, Wales and the Rest of the UK (RUK)) level, where the Rest of the UK is England and Northern Ireland. However, we also construct a more rudimentary four-region (Scotland, Wales, England and Ireland) set of IO and SAM accounts by constructing a separate Northern Ireland accounts. The inter-regional IO and SAM models are produced for the year 1999. This was determined by the availability of consistent data. In Section II we describe the construction of a three-region Input-Output model for the United Kingdom, which includes the regions of Scotland, Wales and the Rest of the UK (RUK). In Section III we extend the three-region model to construct an inter-regional Social Accounting Matrix. Section IV reports some results using the three-region IO and SAM models. In Section V, we generate a four-region IO and SAM model for the UK, which disaggregates Northern Ireland from the Rest of the UK, and provide some results using the four-region IO and SAM models. Section VI offers our conclusions
An extension and application of the Leontief pollution model for waste generation and disposal in Scotland
Solid waste generation, treatment and disposal are important policy concerns for the Scottish Parliament. As a result of the Environment Act 1995, a National Waste Strategy for Scotland was introduced with the general aim of reducing the amount of waste produced and dealing with what is produced in more sustainable ways. This implies the need for an empirical framework to inform policymakers regarding the relationship between economic activity and waste generation, treatment and disposal and the likely impacts of any policy actions or other disturbances on all types of sustainability indicators. In this paper we report on a study to develop an extended input-output (IO) system of the type originally proposed in the seminal paper by Leontief (1970). This involves extending the standard IOaccounts to take account of pollution or waste generation as an additional output accompanying production and consumption activities in the economy and of the activity required to clean up (or prevent) these unwanted outputs. The extension of IO tables to take account of pollution/waste generation is relatively widespread in the literature. It is usually achieved through the introduction of physical pollution/waste-output coefficients, and has been previously applied to Scotland for the case ofair pollution (see McNicoll & Blackmore, 1993, McGregor et al, 2001). Such an approach allows us to examine the impact of the economy on the environment, in terms of the amount of pollution/waste emitted as a result of economic activity. However, it does not allow us to track the feedback from the environment to the economy in terms of the resources used in environmental cleaning. If we areinterested in this aspect, we need to identify the input structure of any pollution abatement or waste disposal activities and identify columns in the IO tables representing cleaning activities
The Richard commission and the financing of devolved government : the economics of devolution in Wales: Briefing No. 8
If the Barnett formula is rigorously applied to determine the budget of the Welsh Assembly Government, this will ultimately adversely affect the economy of Wales by limiting the growth in aggregate demand. This effect is reinforced now that population weights determining rises in expenditure in Wales (and Scotland and Northern Ireland) are regularly up-dated. There is some controversy in Wales about whether some form of needs-assessment exercise would favour Wales relative to its current position. What is clear is that the outcome of a rigorous, long term application of the Barnett formula would be a share of UK public expenditures in Wales (and Scotland and Northern Ireland) that was almost certainly below the level that would be dictated by any conventional understanding of 'needs'. The impact of the tax-varying power favoured by the Richard Commission is ambiguous, with the direction of effects dependent on the reaction of the current labour force and potential migrants. If workers insist on full compensation for loss of income to tax through a rise in gross wages a tax rise would lead to an economic contraction. However, if workers value the additional public services financed by the tax rise as equal to their loss of disposable income, this effect can be avoided. Much in other words would depend on how the proceeds of the tax rise were spen
The national impact of regional policy : policy simulation with labour market constraints in a two-regional computable general equilibrium model
The first step in a comprehensive evaluation of regional policy is to identify its full spatial impact. This involves two tasks. The first is to determine the form and strength of inter-regional linkages. The second is to specify the national constraints within which the system of regional economies operates. In this paper we use simulation results from a two-region Computable General Equilibrium (CGE) model of Scotland and the rest of the UK (RUK) to investigate these issues. The inter-regional linkages incorporate trade and income flows, inter-regional capital mobility and migration. The constraint that we focus on is an overall national population constraint and its impact on regional wage determination. The paper is structured in the following way. Section 2 outlines the AMOSRUK modelling framework. Section 3 describes the alternative labour-market model configurations used in the simulations. Section 4 reports the results for the model simulation and Section 5 is a short conclusion
Cell wall elongation mode in Gram-negative bacteria is determined by peptidoglycan architecture
Cellular integrity and morphology of most bacteria is maintained by cell wall peptidoglycan,
the target of antibiotics essential in modern healthcare. It consists of glycan strands,
cross-linked by peptides, whose arrangement determines cell shape, prevents lysis due to
turgor pressure and yet remains dynamic to allow insertion of new material, and hence
growth. The cellular architecture and insertion pattern of peptidoglycan have remained
elusive. Here we determine the peptidoglycan architecture and dynamics during growth in
rod-shaped Gram-negative bacteria. Peptidoglycan is made up of circumferentially oriented
bands of material interspersed with a more porous network. Super-resolution fluorescence
microscopy reveals an unexpected discontinuous, patchy synthesis pattern. We present
a consolidated model of growth via architecture-regulated insertion, where we propose only
the more porous regions of the peptidoglycan network that are permissive for synthesis
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Numerical simulation of the Beta II experiment
The transport code FRT which is a 1-1/2-D transport-equilibrium code for an axisymmetric plasma was used to simulate the decay of the plasma and magnetic fields of the Beta II experiment. A comparison is made between the experimentally determined decay times for the magnetic fields and particle confinement times and the computed decay times. It is found that 1% oxygen impurity is enough to clamp the electron temperature below the radiation barrier, which is in agreement with the experiment
Bacterial Cell Enlargement Requires Control of Cell Wall Stiffness Mediated by Peptidoglycan Hydrolases.
Most bacterial cells are enclosed in a single macromolecule of the cell wall polymer, peptidoglycan, which is required for shape determination and maintenance of viability, while peptidoglycan biosynthesis is an important antibiotic target. It is hypothesized that cellular enlargement requires regional expansion of the cell wall through coordinated insertion and hydrolysis of peptidoglycan. Here, a group of (apparent glucosaminidase) peptidoglycan hydrolases are identified that are together required for cell enlargement and correct cellular morphology of Staphylococcus aureus, demonstrating the overall importance of this enzyme activity. These are Atl, SagA, ScaH, and SagB. The major advance here is the explanation of the observed morphological defects in terms of the mechanical and biochemical properties of peptidoglycan. It was shown that cells lacking groups of these hydrolases have increased surface stiffness and, in the absence of SagB, substantially increased glycan chain length. This indicates that, beyond their established roles (for example in cell separation), some hydrolases enable cellular enlargement by making peptidoglycan easier to stretch, providing the first direct evidence demonstrating that cellular enlargement occurs via modulation of the mechanical properties of peptidoglycan. IMPORTANCE: Understanding bacterial growth and division is a fundamental problem, and knowledge in this area underlies the treatment of many infectious diseases. Almost all bacteria are surrounded by a macromolecule of peptidoglycan that encloses the cell and maintains shape, and bacterial cells must increase the size of this molecule in order to enlarge themselves. This requires not only the insertion of new peptidoglycan monomers, a process targeted by antibiotics, including penicillin, but also breakage of existing bonds, a potentially hazardous activity for the cell. Using Staphylococcus aureus, we have identified a set of enzymes that are critical for cellular enlargement. We show that these enzymes are required for normal growth and define the mechanism through which cellular enlargement is accomplished, i.e., by breaking bonds in the peptidoglycan, which reduces the stiffness of the cell wall, enabling it to stretch and expand, a process that is likely to be fundamental to many bacteria
The architecture of the Gram-positive bacterial cell wall
The primary structural component of the bacterial cell wall is peptidoglycan, which is essential for viability and the synthesis of which is the target for crucial antibiotics1,2. Peptidoglycan is a single macromolecule made of glycan chains crosslinked by peptide side branches that surrounds the cell, acting as a constraint to internal turgor1,3. In Gram-positive bacteria, peptidoglycan is tens of nanometres thick, generally portrayed as a homogeneous structure that provides mechanical strength4,5,6. Here we applied atomic force microscopy7,8,9,10,11,12 to interrogate the morphologically distinct Staphylococcus aureus and Bacillus subtilis species, using live cells and purified peptidoglycan. The mature surface of live cells is characterized by a landscape of large (up to 60 nm in diameter), deep (up to 23 nm) pores constituting a disordered gel of peptidoglycan. The inner peptidoglycan surface, consisting of more nascent material, is much denser, with glycan strand spacing typically less than 7 nm. The inner surface architecture is location dependent; the cylinder of B. subtilis has dense circumferential orientation, while in S. aureus and division septa for both species, peptidoglycan is dense but randomly oriented. Revealing the molecular architecture of the cell envelope frames our understanding of its mechanical properties and role as the environmental interface13,14, providing information complementary to traditional structural biology approaches
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