635 research outputs found
The Delineation and Apportionment of an EU Consolidated Tax Base for Multi-jurisdictional Corporate Income Taxation: a Review of Issues and Options.
The Commission Services study on Company Taxation in the Internal Market and the Communications COM(2001)582 and COM(2003)726 on EU company taxation presented a long-term strategy to tackle the corporate income tax obstacles in the Internal Market by providing multi-jurisdictional companies with a consolidated tax base for their EU-wide activities for corporate taxation purposes. This comprehensive approach relies on a number of crucial steps such as delineating the CTB and choosing the mechanism for apportioning the multinationals' tax bases between the relevant Member States, so that they can then apply the national corporation tax rate to their respective shares. This work systematically addresses some of the fundamental questions that arise when considering the design of a consolidation + apportionment system for sharing multinationals' consolidated profits between EU Member States.European Union, Corporate Taxation, multinational taxation, formula apportionment
Discovery of interstellar isocyanogen (CNCN): further evidence that dicyanopolyynes are abundant in space
It is thought that dicyanopolyynes could be potentially abundant interstellar
molecules, although their lack of dipole moment makes it impossible to detect
them through radioastronomical techniques. Recently, the simplest member of
this chemical family, cyanogen (NCCN), was indirectly probed for the first time
in interstellar space through the detection of its protonated form toward the
dense clouds L483 and TMC-1. Here we present a second firm evidence of the
presence of NCCN in interstellar space, namely the detection of the metastable
and polar isomer isocyanogen (CNCN). This species has been identified in L483
and tentatively in TMC-1 by observing various rotational transitions in the 3
mm band with the IRAM 30m telescope. We derive beam-averaged column densities
for CNCN of 1.6e12 cm-2 in L483 and 9e11 cm-2 in TMC-1, which imply fractional
abundances relative to H2 in the range (5-9)e-11. While the presence of NCCN in
interstellar clouds seems out of doubt owing to the detection of NCCNH+ and
CNCN, putting tight constraints on its abundance is still hampered by the poor
knowledge of the chemistry that links NCCN with NCCNH+ and especially with
CNCN. We estimate that NCCN could be fairly abundant, in the range 1e-9 - 1e-7
relative to H2, as other abundant nitriles like HCN and HC3N.Comment: Accepted for publication in ApJ Letter
Local Kondo temperatures in atomic chains
We study the effect of disorder in strongly interacting small atomic chains.
Using the Kotliar- Ruckenstein slave-boson approach we diagonalize the
Hamiltonian via scattering matrix theory. We numerically solve the Kondo
transmission and the slave-boson parameters that allow us to calculate the
Kondo temperature. We demonstrate that in the weak disorder regime, disorder in
the energy levels of the dopants induces a non-screened disorder in the Kondo
couplings of the atoms. We show that disorder increases the Kondo temperature
of a perfect chain. We find that this disorder in the couplings comes from a
local distribution of Kondo temperatures along the chain. We propose two
experimental setups where the impact of local Kondo temperatures can be
observed
Detection of interstellar HCS and its metastable isomer HSC: new pieces in the puzzle of sulfur chemistry
We present the first identification in interstellar space of the thioformyl
radical (HCS) and its metastable isomer HSC. These species were detected toward
the molecular cloud L483 thanks to observations carried out with the IRAM 30m
telescope in the 3 mm band. We derive beam-averaged column densities of 7e12
cm-2 for HCS and 1.8e11 cm-2 for HSC, which translate to fractional abundances
relative to H2 of 2e-10 and 6e-12, respectively. Although the amount of sulfur
locked by these radicals is low, their detection allows to put interesting
constraints on the chemistry of sulfur in dark clouds. Interestingly, the
H2CS/HCS abundance ratio is found to be quite low, around 1, in contrast with
the oxygen analogue case, in which the H2CO/HCO abundance ratio is around 10 in
dark clouds. Moreover, the radical HCS is found to be more abundant than its
oxygen analogue, HCO. The metastable species HOC, the oxygen analogue of HSC,
has not been yet observed in space. These observational constraints are
confronted with the outcome of a recent model of the chemistry of sulfur in
dark clouds. The model underestimates the fractional abundance of HCS by at
least one order of magnitude, overestimates the H2CS/HCS abundance ratio, and
does not provide an abundance prediction for the metastable isomer HSC. These
observations should prompt a revision of the chemistry of sulfur in
interstellar clouds.Comment: Accepted for publication in A&A Letter
The atmospheric chemistry of the warm Neptune GJ 3470b: influence of metallicity and temperature on the CH4/CO ratio
Current observation techniques are able to probe the atmosphere of some giant
exoplanets and get some clues about their atmospheric composition. However, the
chemical compositions derived from observations are not fully understood, as
for instance in the case of the CH4/CO abundance ratio, which is often inferred
different from what has been predicted by chemical models. Recently, the warm
Neptune GJ3470b has been discovered and because of its close distance from us
and high transit depth, it is a very promising candidate for follow up
characterisation of its atmosphere. We study the atmospheric composition of
GJ3470b in order to compare with the current observations of this planet, to
prepare the future ones, but also as a typical case study to understand the
chemical composition of warm (sub-)Neptunes. The metallicity of such
atmospheres is totally uncertain, and vary probably to values up to 100x solar.
We explore the space of unknown parameters to predict the range of possible
atmospheric compositions. Within the parameter space explored we find that in
most cases methane is the major carbon-bearing species. We however find that in
some cases, typically for high metallicities with a sufficiently high
temperature the CH4/CO abundance ratio can become lower than unity, as
suggested by some multiwavelength photometric observations of other warm
(sub-)Neptunes, such as GJ1214b and GJ436b. As for the emission spectrum of
GJ3470b, brightness temperatures at infrared wavelengths may vary between 400
and 800K depending on the thermal profile and metallicity. Combined with a hot
temperature profile, a substantial enrichment in heavy elements by a factor of
100 with respect to the solar composition can shift the carbon balance in
favour of carbon monoxide at the expense of CH4. Nevertheless, current
observations of this planet do not allow yet to determine which model is more
accurate.Comment: 12 pages, 8 figures, accepted in Astronomy & Astrophysic
Les espaces de l'halieutique
On considère que deux marchés d'un bien donné sont intégrés lorsque leurs prix d'échange évoluent parallèlement dans le temps. On peut alors parler de marchés cointégrés. La cointégration est un outil économétrique permettant d'établir des relations stables et stationnaires à long terme pour des processus non stationnaires. La stationnarité est un problème très fréquent des variables économiques et notamment des séries de prix des produits de la mer. Ce problème étant classiquement résolu par la différenciation des processus sous peine d'une perte d'information des effets à long terme. La cointégration surmonte cela en changeant la structure du modèle économétrique initial avec l'introduction d'un élément correcteur de l'erreur. L'objectif de ce travail est d'explorer l'évolution des prix pour des marchés différents afin d'étudier de possibles relations à long terme entre eux. On utilisera l'exemple du marché du merlu en Bretagne pour appliquer cette méthode. On retiendra des prix mensuels et hebdomadaires des ventes de merlu. Les résultats nous montrent l'existence d'une étendue spatiale régionale du marché du merlu à l'intérieur duquel les prix évoluent sous une même tendance à long terme en dépit des possibles différentes à court terme. (Résumé d'auteur
Confirmation of circumstellar phosphine
Phosphine (PH3) was tentatively identified a few years ago in the carbon star
envelopes IRC+10216 and CRL2688 from observations of an emission line at 266.9
GHz attributable to the J=1-0 rotational transition. We report the detection of
the J=2-1 rotational transition of PH3 in IRC+10216 using the HIFI instrument
on board Herschel, which definitively confirms the identification of PH3.
Radiative transfer calculations indicate that infrared pumping to excited
vibrational states plays an important role in the excitation of PH3 in the
envelope of IRC+10216, and that the observed lines are consistent with
phosphine being formed anywhere between the star and 100 R* from the star, with
an abundance of 1e-8 relative to H2. The detection of PH3 challenges chemical
models, none of which offers a satisfactory formation scenario. Although PH3
locks just 2 % of the total available phosphorus in IRC+10216, it is together
with HCP, one of the major gas phase carriers of phosphorus in the inner
circumstellar layers, suggesting that it could be also an important phosphorus
species in other astronomical environments. This is the first unambiguous
detection of PH3 outside the solar system, and a further step towards a better
understanding of the chemistry of phosphorus in space.Comment: Accepted for publication in ApJ Letter
Detection of circumstellar CH2CHCN, CH2CN, CH3CCH and H2CS
We report on the detection of vinyl cyanide (CH2CHCN), cyanomethyl radical
(CH2CN), methylacetylene (CH3CCH) and thioformaldehyde (H2CS) in the C-rich
star IRC +10216. These species, which are all known to exist in dark clouds,
are detected for the first time in the circumstellar envelope around an AGB
star. The four molecules have been detected trough pure rotational transitions
in the course of a 3 mm line survey carried out with the IRAM 30-m telescope.
The molecular column densities are derived by constructing rotational
temperature diagrams. A detailed chemical model of the circumstellar envelope
is used to analyze the formation of these molecular species. We have found
column densities in the range 5 x 10^(12)- 2 x 10^(13) cm^(-2), which
translates to abundances relative to H2 of several 10^(-9). The chemical model
is reasonably successful in explaining the derived abundances through gas phase
synthesis in the cold outer envelope. We also find that some of these
molecules, CH2CHCN and CH2CN, are most probably excited trough infrared pumping
to excited vibrational states. The detection of these species stresses the
similarity between the molecular content of cold dark clouds and C-rich
circumstellar envelopes. However, some differences in the chemistry are
indicated by the fact that in IRC +10216 partially saturated carbon chains are
present at a lower level than those which are highly unsaturated, while in
TMC-1 both types of species have comparable abundances.Comment: 9 pages, 5 figures; accepted for publication in A&
Clinical Decision Support Systems with Game-based Environments, Monitoring Symptoms of Parkinson’s Disease with Exergames
Parkinson’s Disease (PD) is a malady caused by progressive neuronal degeneration, deriving in several physical and cognitive symptoms that worsen with time. Like many other chronic diseases, it requires constant monitoring to perform medication and therapeutic adjustments. This is due to the significant variability in PD symptomatology and progress between patients. At the moment, this monitoring requires substantial participation from caregivers and numerous clinic visits. Personal diaries and questionnaires are used as data sources for medication and therapeutic adjustments. The subjectivity in these data sources leads to suboptimal clinical decisions. Therefore, more objective data sources are required to better monitor the progress of individual PD patients. A potential contribution towards more objective monitoring of PD is clinical decision support systems. These systems employ sensors and classification techniques to provide caregivers with objective information for their decision-making. This leads to more objective assessments of patient improvement or deterioration, resulting in better adjusted medication and therapeutic plans. Hereby, the need to encourage patients to actively and regularly provide data for remote monitoring remains a significant challenge. To address this challenge, the goal of this thesis is to combine clinical decision support systems with game-based environments. More specifically, serious games in the form of exergames, active video games that involve physical exercise, shall be used to deliver objective data for PD monitoring and therapy. Exergames increase engagement while combining physical and cognitive tasks. This combination, known as dual-tasking, has been proven to improve rehabilitation outcomes in PD: recent randomized clinical trials on exergame-based rehabilitation in PD show improvements in clinical outcomes that are equal or superior to those of traditional rehabilitation. In this thesis, we present an exergame-based clinical decision support system model to monitor symptoms of PD. This model provides both objective information on PD symptoms and an engaging environment for the patients. The model is elaborated, prototypically implemented and validated in the context of two of the most prominent symptoms of PD: (1) balance and gait, as well as (2) hand tremor and slowness of movement (bradykinesia). While balance and gait affections increase the risk of falling, hand tremors and bradykinesia affect hand dexterity. We employ Wii Balance Boards and Leap Motion sensors, and digitalize aspects of current clinical standards used to assess PD symptoms. In addition, we present two dual-tasking exergames: PDDanceCity for balance and gait, and PDPuzzleTable for tremor and bradykinesia. We evaluate the capability of our system for assessing the risk of falling and the severity of tremor in comparison with clinical standards. We also explore the statistical significance and effect size of the data we collect from PD patients and healthy controls. We demonstrate that the presented approach can predict an increased risk of falling and estimate tremor severity. Also, the target population shows a good acceptance of PDDanceCity and PDPuzzleTable. In summary, our results indicate a clear feasibility to implement this system for PD. Nevertheless, long-term randomized clinical trials are required to evaluate the potential of PDDanceCity and PDPuzzleTable for physical and cognitive rehabilitation effects
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