Tax reform in the UK and changes in the progressivity of the tax system, 1985-95

From the middle of the 1980s until the end of that decade, the government experienced a growing economy and consequently buoyant tax revenues. In addition to cutting the public sector borrowing requirement (PSBR) and increasing spending, these revenues were used as a means of financing massive tax cuts, and in particular cuts in income tax rates. By the early 1990s, however,it had become clear that tax revenues had been cut to an unsustainably low level as recession led to a PSBR that threatened to run out of control. In response to this, in the two Budgets of 1993 the two Chancellors introduced a package of tax increases which, in terms of revenue raised, will reverse most of the tax reductions of the late 1980s. But taxes were increased in a way very different from that in which they were reduced. The overall effect has been a substantial reform of the UK tax system. This paper examines the changes that have been made in the tax system as they affect the personal sector, i.e. changes to taxes on personal income, on personal property and on expenditure. We start the analysis with the 1985 tax system as the base, for it was in 1986 that the first cut in income tax rates was introduced and the trend for significant tax cuts was set. And it was from this date that taxation as a proportion of GDP started to fall steadily until the end of the 1980s. We end the analysis with the tax system as it would have been left at the end of 1995 by the tax changes announced in the 1993 Budgets. A decade of contrasting tax changes are examined.

Housing benefit and financial returns to employment for tenants in the social sector

This paper examines the impact of the UK housing benefit system on the financial returns to employment of people in local authority or Housing Association accommodation. It outlines the current structure of housing benefit and examines its effects on the returns to employment using data from the Family Expenditure Survey. It analyses the consequences of a number of reforms to the current system — lowering social rents, increasing the levels of housing benefit received in work and restricting the amount of rent covered by housing benefit payments. This analysis highlights the trade-offs involved in various strategies available for restructuring the present system.

A change in the midpoint potential of the quinone QA in Photosystem II associated with photoactivation of oxygen evolution

AbstractThe effect of photoactivation (the assembly of the Mn cluster involved in oxygen evolution) in Photosystem II (PS II), on the redox midpoint potential of the primary quinone electron acceptor, QA, has been investigated. Measurements of the redox state of QA were performed using chlorophyll fluorescence. Cells of Scenedesmus obliquus were grown in the dark to obtain PS II lacking the oxygen-evolving complex. Growth in the light leads to photoactivation. The midpoint potential of QA was shifted, upon photoactivation, from + 110 mV to −80 mV. In cells of a low-fluorescence mutant, LF1, that is unable to assemble the oxygen-evolving complex but that has an otherwise normal PS II, the higher potential form of QA was found. NH2OH treatment of spinach PS II, which releases the Mn and thus inactivates the oxygen-evolving complex, causes an upshift of the redox potential of QA (Krieger and Weis (1992) Photosynthetica 27, 89–98). Oxygen evolution can be reconstituted by incubation in the light in the presence of MnCl2 and CaCl2. Such photoactivation caused the midpoint potential of QA to be shifted back from around +55 mV to lower potentials (−80 mV), typical for active PS II. The above results indicate that the state of the donor side of PS II has a direct influence on the properties of the acceptor side. It is suggested that the change from the high- to the low-potential form of QA may represent a mechanism for protection of PS II during the assembly of the O2-evolving enzyme

Physiological characterisation of magnesium deficiency in sugar beet: acclimation to low magnesium differentially affects photosystemsI and II

Magnesium deficiency in plants is a widespread problem, affecting productivity and quality in agriculture, yet at a physiological level it has been poorly studied in crop plants. Here, a physiological characterization of Mg deficiency in Beta vulgaris L., an important crop model, is presented. The impact of Mg deficiency on plant growth, mineral profile and photosynthetic activity was studied. The aerial biomass of plants decreased after 24days of hydroponic culture in Mg-free nutrient solution, whereas the root biomass was unaffected. Analysis of mineral profiles revealed that Mg decreased more rapidly in roots than in shoots and that shoot Mg content could fall to 3mgg−1 DW without chlorosis development and with no effect on photosynthetic parameters. Sucrose accumulated in most recently expanded leaves before any loss in photosynthetic activity. During the development of Mg deficiency, the two photosystems showed sharply contrasting responses. Data were consistent with a down-regulation of PSII through a loss of antenna, and of PSI primarily through a loss of reaction centres. In each case, the net result was a decrease in the overall rate of linear electron transport, preventing an excess of reductant being produced during conditions under which sucrose export away from mature leaf was restricte

Going against the Grain: Overturning the received wisdom of a field takes not just strong evidence, but a strong personality. For one reproductive biologist, only time will tell whether such challenges are worth the risks in today's pressurized research climate.

A reproductive biologist's research at Massachusetts General Hospital in Boston has stoked a controversy about whether female mammals can renew egg cells

Flux balance analysis reveals acetate metabolism modulates cyclic electron flow and alternative glycolytic pathways in Chlamydomonas reinhardtii

Cells of the green alga Chlamydomonas reinhardtii cultured in the presence of acetate perform mixotrophic growth, involving both photosynthesis and organic carbon assimilation. Under such conditions, cells exhibit a reduced capacity for photosynthesis but a higher growth rate, compared to phototrophic cultures. Better understanding of the downregulation of photosynthesis would enable more efficient conversion of carbon into valuable products like biofuels. In this study, Flux Balance Analysis (FBA) and Flux Variability Analysis (FVA) have been used with a genome scale model of C. reinhardtii to examine changes in intracellular flux distribution in order to explain their changing physiology. Additionally, a reaction essentiality analysis was performed to identify which reaction subsets are essential for a given growth condition. Our results suggest that exogenous acetate feeds into a modified tricarboxylic acid cycle, which bypasses the CO2 evolution steps, explaining increases in biomass, consistent with experimental data. In addition, reactions of the oxidative pentose phosphate and glycolysis pathways, inactive under phototrophic conditions, show substantial flux under mixotrophic conditions. Importantly, acetate addition leads to an increased flux through cyclic electron flow (CEF), but results in a repression of CO2 fixation via Rubisco, explaining the down regulation of photosynthesis. However, although CEF enhances growth on acetate, it is not essential – impairment of CEF results in alternative metabolic pathways being increased. We have demonstrated how the reactions of photosynthesis interconnect with carbon metabolism on a global scale, and how systems approaches play a viable tool in understanding complex relationships at the scale of the organism

Direct sums and the Szlenk index

For $\alpha$ an ordinal and $1<p<\infty$, we determine a necessary and sufficient condition for an $\ell_p$-direct sum of operators to have Szlenk index not exceeding $\omega^\alpha$. It follows from our results that the Szlenk index of an $\ell_p$-direct sum of operators is determined in a natural way by the behaviour of the $\epsilon$-Szlenk indices of its summands. Our methods give similar results for $c_0$-direct sums.Comment: The proof of Proposition~2.4 has changed, with some of the arguments transferred to the proof of an added-in lemma, Lemma~2.8. Changes have been made to the Applications sectio

A biomechanical assessment of superior shoulder translation after reconstruction of anterior glenoid bone defects: The Latarjet procedure versus allograft reconstruction

BACKGROUND: The coracoacromial ligament (CAL) is an important restraint to superior shoulder translation. The effect of CAL release on superior stability following the Latarjet is unknown; therefore, our purpose was to compare the effect of two Latarjet techniques and allograft reconstruction on superior instability. MATERIALS AND METHODS: Eight cadaveric specimens were tested on a simulator. Superior translation was monitored following an axial force in various glenohumeral rotations (neutral, internal, and external) with and without muscle loading. Three intact CAL states were tested (intact specimen, 30% glenoid bone defect, and allograft reconstruction) and two CAL deficient states (classic Latarjet (classicLAT) and congruent-arc Latarjet (congruentLAT)). RESULTS: In neutral without muscle loading, a significant increase in superior translation occurred with the classicLAT as compared to 30% defect (P = 0.046) and allograft conditions (P = 0.041). With muscle loading, the classicLAT (P = 0.005, 0.002) and the congruentLAT (P = 0.018, 0.021) had significantly greater superior translation compared to intact and allograft, respectively. In internal rotation, only loaded tests produced significant results; specifically, classicLAT increased translation compared to all intact CAL states (P < 0.05). In external rotation, only unloaded tests produced significant results with classicLAT and congruentLAT allowing greater translations than intact (P ≤ 0.028). For all simulations, the allograft was not significantly different than intact (P > 0.05) and no differences (P = 1.0) were found between classicLAT and congruentLAT. DISCUSSION: In most simulations, CAL release with the Latarjet lead to increased superior humeral translation. CONCLUSION: The choice of technique for glenoid bone loss reconstruction has implications on the magnitude of superior humeral translation. This previously unknown effect requires further study to determine its clinical and kinematic outcomes