7,617 research outputs found
Rationale and protocol for a systematic review and meta-analysis on reduced data gathering in people with delusions
Can Tax Progression Raise Employment? A Study of Four European Countries
This paper shows that increases in direct tax progression tend to reduce wages and increase welfare and employment, even in a model allowing for labour supply effects. The employment effect is reversed when benefit levels are low, however. The model shows the different impacts on full and parttime workers, and on men and women. The countries modelled are France, Germany, Italy and the UK. An efficiency wage sector with training costs generates unemployment effects. Households choose between an efficiency wage sector and a market-clearing sector.
Attentional load and sensory competition in human vision: Modulation of fMRI responses by load fixation during task-irrelevant stimulation in the peripheral visual field.
Perceptual suppression of distractors may depend on both endogenous and exogenous factors, such as attentional load of the current task and sensory competition among simultaneous stimuli, respectively. We used functional magnetic resonance imaging (fMRI) to compare these two types of attentional effects and examine how they may interact in the human brain. We varied the attentional load of a visual monitoring task performed on a rapid stream at central fixation without altering the central stimuli themselves, while measuring the impact on fMRI responses to task-irrelevant peripheral checkerboards presented either unilaterally or bilaterally. Activations in visual cortex for irrelevant peripheral stimulation decreased with increasing attentional load at fixation. This relative decrease was present even in V1, but became larger for successive visual areas through to V4. Decreases in activation for contralateral peripheral checkerboards due to higher central load were more pronounced within retinotopic cortex corresponding to 'inner' peripheral locations relatively near the central targets than for more eccentric 'outer' locations, demonstrating a predominant suppression of nearby surround rather than strict 'tunnel vision' during higher task load at central fixation. Contralateral activations for peripheral stimulation in one hemifield were reduced by competition with concurrent stimulation in the other hemifield only in inferior parietal cortex, not in retinotopic areas of occipital visual cortex. In addition, central attentional load interacted with competition due to bilateral versus unilateral peripheral stimuli specifically in posterior parietal and fusiform regions. These results reveal that task-dependent attentional load, and interhemifield stimulus-competition, can produce distinct influences on the neural responses to peripheral visual stimuli within the human visual system. These distinct mechanisms in selective visual processing may be integrated within posterior parietal areas, rather than earlier occipital cortex
Carbon Abatement and its international effects in Europe including effects on other pollutants: a general equilibrium approach
This paper outlines the development of a CGE model as a tool for analysing many of the issues relating to the introduction of environmental taxation, such as interaction with other taxes, revenue recycling, international carbon 'leakage' and tax export effects. The model is linked to IIASA's RAINS model to expand the analysis to cover other cross-boundary pollution. Analysis of a 30 ECU per tonne carbon tax applied in Germany, the UK and the rest of the European Union indicate that it could achieve savings of the order of 20 per cent in carbon emissions compared to business as usual, at little economic cost to the EU countries. The emission savings may be slightly higher in Germany and lower in the UK than the rest of the EU, while the latter would also gain more from terms of trade effects. The tax would bring substantial savings in sulphur emissions. Alternatively, if emissions were allowed to stay constant, the saving on abatement technology would mean a modest improvement in the net cost of the tax. Effects on Nitrogen emissions are smaller.
The Allocation of Carbon Permits within One Country : A General Equilibrium Analysis of the United Kingdom
As part of the Kyoto agreement on limiting carbon emissions, from 2008 onwards an international market in auction able carbon permits will be established. This raises the issue of whether trading should be simply between governments or between companies, or in the latter case how such permits should be allocated. Our paper uses the British section of a CGE model of the European energy sectors to evaluate the economics of various methods of allocating permits within a country, as discussed in Lord Marshall’s recent report to the British government. The option of allocation entirely by auction is similar to the setting of a carbon tax, and the recycling of revenues to reduce or offset other economic distortions could produce a potential net benefit to incomes and employment. 'Grandfathering' some of the permits free to large firms, according to their base year carbon emissions, would mean loss of the benefits of recycling auction revenues. This might be exacerbated if it created windfall profits repatriated by foreign shareholders. The third major alternative is to review the allocation regularly, awarding permits to all firms according to a ‘benchmark’ allocation, based on 'best practice' as estimated by outside experts. This would be similar in practice to recycling the revenue as an output subsidy to the industry, though it could be complicated to implement. Such a system could allow much of the potential ‘double dividend’ to be realized, though it might still be preferable to auction permits, with the revenues used to offset taxes across a wider spread of industry
On the calibration of the relation between geometric albedo and polarimetric properties for the asteroids
We present a new extensive analysis of the old problem of finding a
satisfactory calibration of the relation between the geometric albedo and some
measurable polarization properties of the asteroids. To achieve our goals, we
use all polarimetric data at our disposal. For the purposes of calibration, we
use a limited sample of objects for which we can be confident to know the
albedo with good accuracy, according to previous investigations of other
authors. We find a new set of updated calibration coefficients for the
classical slope - albedo relation, but we generalize our analysis and we
consider also alternative possibilities, including the use of other
polarimetric parameters, one being proposed here for the first time, and the
possibility to exclude from best-fit analyzes the asteroids having low albedos.
We also consider a possible parabolic fit of the whole set of data.Comment: Accepted by MNRA
Can re-entrance be observed in force induced transitions?
A large conformational change in the reaction co-ordinate and the role of the
solvent in the formation of base-pairing are combined to settle a long standing
issue {\it i.e.} prediction of re-entrance in the force induced transition of
DNA. A direct way to observe the re-entrance, i.e a strand goes to the closed
state from the open state and again to the open state with temperature, appears
difficult to be achieved in the laboratory. An experimental protocol (in direct
way) in the constant force ensemble is being proposed for the first time that
will enable the observation of the re-entrance behavior in the
force-temperature plane. Our exact results for small oligonucleotide that forms
a hairpin structure provide the evidence that re-entrance can be observed.Comment: 12 pages and 5 figures (RevTex4). Accepted in Europhys Lett. (2009
Happiness as stable extraversion : internal consistency reliability and construct validity of the Oxford Happiness Questionnaire among undergraduate students
The Oxford Happiness Questionnaire (OHQ) was developed by Hills and Argyle (2002) to provide a more accessible equivalent measure of the Oxford Happiness Inventory (OHI). The aim of the present study was to examine the internal consistency reliability, and construct validity of this new instrument alongside the Eysenckian dimensional model of personality. The Oxford Happiness Questionnaire was completed by a sample of 131 undergraduate students together with the abbreviated form of the Revised Eysenck Personality Questionnaire. The data demonstrated good internal consistency reliability (alpha = .92) and good construct validity in terms of positive association with extraversion (r = .38 p < .001) and negative association with neuroticism (r = −.57 p < .001). The kind of happiness measured by the OHQ is clearly associated with stable extraversion
Phase transition in the Countdown problem
Here we present a combinatorial decision problem, inspired by the celebrated
quiz show called the countdown, that involves the computation of a given target
number T from a set of k randomly chosen integers along with a set of
arithmetic operations. We find that the probability of winning the game
evidences a threshold phenomenon that can be understood in the terms of an
algorithmic phase transition as a function of the set size k. Numerical
simulations show that such probability sharply transitions from zero to one at
some critical value of the control parameter, hence separating the algorithm's
parameter space in different phases. We also find that the system is maximally
efficient close to the critical point. We then derive analytical expressions
that match the numerical results for finite size and permit us to extrapolate
the behavior in the thermodynamic limit.Comment: Submitted for publicatio
- …
