2,365 research outputs found
The distribution of effective tax burdens in four EU countries
National policymakers are increasingly aware that their tax policy options are constrained by international tax competition. Important features of national tax systems - notably the tax mix, tax rates and rules which define the tax base - will influence decisions of firms and individuals regarding the location and (re)structuring of economic activities. The aim of the present paper is twofold: Firstly, we detail the tax mix of four member states of the European Union (Germany, The Netherlands, Spain and United Kingdom). Secondly, the paper aims to trace the distribution of the tax burden over rich and poor households in these four countries. Although tax mix and tax rates differ considerably among the four countries included in the study, the distribution of tax burdens proves to be amazingly similar.Distribution of tax burden, European Union; tax mix of Germany, the Netherlands, Spain and United Kingdom
Human visual cortical responses to specular and matte motion flows
Determining the compositional properties of surfaces in the environment is an important visual capacity. One such property is specular reflectance, which encompasses the range from matte to shiny surfaces. Visual estimation of specular reflectance can be informed by characteristic motion profiles; a surface with a specular reflectance that is difficult to determine while static can be confidently disambiguated when set in motion. Here, we used fMRI to trace the sensitivity of human visual cortex to such motion cues, both with and without photometric cues to specular reflectance. Participants viewed rotating blob-like objects that were rendered as images (photometric) or dots (kinematic) with either matte-consistent or shiny-consistent specular reflectance profiles. We were unable to identify any areas in low and mid-level human visual cortex that responded preferentially to surface specular reflectance from motion. However, univariate and multivariate analyses identified several visual areas; V1, V2, V3, V3A/B, and hMT+, capable of differentiating shiny from matte surface flows. These results indicate that the machinery for extracting kinematic cues is present in human visual cortex, but the areas involved in integrating such information with the photometric cues necessary for surface specular reflectance remain unclear. © 2015 Kam, Mannion, Lee, Doerschner and Kersten
Surface patterning of carbon nanotubes can enhance their penetration through a phospholipid bilayer
Nanotube patterning may occur naturally upon the spontaneous self-assembly of
biomolecules onto the surface of single-walled carbon nanotubes (SWNTs). It
results in periodically alternating bands of surface properties, ranging from
relatively hydrophilic to hydrophobic, along the axis of the nanotube. Single
Chain Mean Field (SCMF) theory has been used to estimate the free energy of
systems in which a surface patterned nanotube penetrates a phospholipid
bilayer. In contrast to un-patterned nanotubes with uniform surface properties,
certain patterned nanotubes have been identified that display a relatively low
and approximately constant system free energy (10 kT) as the nanotube traverses
through the bilayer. These observations support the hypothesis that the
spontaneous self-assembly of bio-molecules on the surface of SWNTs may
facilitate nanotube transduction through cell membranes.Comment: Published in ACS Nano http://pubs.acs.org/doi/abs/10.1021/nn102763
Optimizing Information Freshness in Wireless Networks under General Interference Constraints
Age of information (AoI) is a recently proposed metric for measuring
information freshness. AoI measures the time that elapsed since the last
received update was generated. We consider the problem of minimizing average
and peak AoI in a wireless networks, consisting of a set of source-destination
links, under general interference constraints. When fresh information is always
available for transmission, we show that a stationary scheduling policy is peak
age optimal. We also prove that this policy achieves average age that is within
a factor of two of the optimal average age. In the case where fresh information
is not always available, and packet/information generation rate has to be
controlled along with scheduling links for transmission, we prove an important
separation principle: the optimal scheduling policy can be designed assuming
fresh information, and independently, the packet generation rate control can be
done by ignoring interference. Peak and average AoI for discrete time G/Ber/1
queue is analyzed for the first time, which may be of independent interest
Perceived usefulness of open educational resources: Impact of switching to online learning for face-to-face and distance learners
This paper reports a study on the perceived usefulness of university students on open educational resources (OER) in relation to the switch of learning mode to online learning during the COVID-19 pandemic. The participants involved two groups of students, one studying in a face-to-face mode and the other in a distance learning mode. They took part in a survey which was conducted in 2019 before the pandemic (with a total of 912 responses) and 2021 during the pandemic (with a total of 1,018 responses). The results show that both groups of students generally perceived OER to be more useful during the pandemic. The specific types of OER which were perceived as relatively more useful include open online courses and open access textbooks. Face-to-face students showed a higher level of perceived usefulness of OER for preparing tests and examinations, while distance learning students perceived OER as more useful for supplementing course materials. They both concerned about the limitations of OER, especially on accuracy and comprehensiveness. The findings suggest the importance of recognizing the diverse needs of the two groups of students and offering appropriate OER support for them
1082-182 Carotid intima-media thickening as surrogate atherosclerosis marker: Is it relevant to the asians?
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