37,219 research outputs found
State Taxation of Unitary Businesses
The income taxation of multistate businesses has created problems for tax administrators, primarily with regard to the question of how to divide the income taxation amongst the multiple states. To address this, the concepts of unitary business and formula apportionment have been created. However, the non-uniform state taxation practices create difficulties even with the existence of these concepts. Some states have adopted the Multistate Tax Compact, but for it to be completely effective there still must be a uniform view adopted on what constitutes a unitary business. This note examines the constitutional issues attendant to developing a standard definition of a unitary business, an in-depth analysis of the unitary business concept and its origins, and proposes a workable definition of a unitary business
State Taxation of Unitary Businesses
The income taxation of multistate businesses has created problems for tax administrators, primarily with regard to the question of how to divide the income taxation amongst the multiple states. To address this, the concepts of unitary business and formula apportionment have been created. However, the non-uniform state taxation practices create difficulties even with the existence of these concepts. Some states have adopted the Multistate Tax Compact, but for it to be completely effective there still must be a uniform view adopted on what constitutes a unitary business. This note examines the constitutional issues attendant to developing a standard definition of a unitary business, an in-depth analysis of the unitary business concept and its origins, and proposes a workable definition of a unitary business
Using coronal seismology to estimate the magnetic field strength in a realistic coronal model
Coronal seismology is extensively used to estimate properties of the corona,
e.g. the coronal magnetic field strength are derived from oscillations observed
in coronal loops. We present a three-dimensional coronal simulation including a
realistic energy balance in which we observe oscillations of a loop in
synthesised coronal emission. We use these results to test the inversions based
on coronal seismology.
From the simulation of the corona above an active region we synthesise
extreme ultraviolet (EUV) emission from the model corona. From this we derive
maps of line intensity and Doppler shift providing synthetic data in the same
format as obtained from observations. We fit the (Doppler) oscillation of the
loop in the same fashion as done for observations to derive the oscillation
period and damping time.
The loop oscillation seen in our model is similar to imaging and
spectroscopic observations of the Sun. The velocity disturbance of the kink
oscillation shows an oscillation period of 52.5s and a damping time of 125s,
both being consistent with the ranges of periods and damping times found in
observation. Using standard coronal seismology techniques, we find an average
magnetic field strength of G for our loop in the simulation,
while in the loop the field strength drops from some 300G at the coronal base
to 50G at the apex. Using the data from our simulation we can infer what the
average magnetic field derived from coronal seismology actually means. It is
close to the magnetic field strength in a constant cross-section flux tube that
would give the same wave travel time through the loop.
Our model produced not only a realistic looking loop-dominated corona, but
also provides realistic information on the oscillation properties that can be
used to calibrate and better understand the result from coronal seismology.Comment: Accepted for publication on A&
In vivo therapeutic efficacy of frog skin-derived peptides against Pseudomonas aeruginosa-induced pulmonary infection
Pseudomonas aeruginosa is an opportunistic and frequently drug-resistant pulmonary pathogen especially in cystic fibrosis sufferers. Recently, the frog skin-derived antimicrobial peptide (AMP) Esc(1-21) and its diastereomer Esc(1-21)-1c were found to possess potent in vitro antipseudomonal activity. Here, they were first shown to preserve the barrier integrity of airway epithelial cells better than the human AMP LL-37. Furthermore, Esc(1-21)-1c was more efficacious than Esc(1-21) and LL-37 in protecting host from pulmonary bacterial infection after a single intra-tracheal instillation at a very low dosage of 0.1 mg/kg. The protection was evidenced by 2-log reduction of lung bacterial burden and was accompanied by less leukocytes recruitment and attenuated inflammatory response. In addition, the diastereomer was more efficient in reducing the systemic dissemination of bacterial cells. Importantly, in contrast to what reported for other AMPs, the peptide was administered at 2 hours after bacterial challenge to better reflect the real life infectious conditions. To the best of our knowledge, this is also the first study investigating the effect of AMPs on airway-epithelia associated genes upon administration to infected lungs. Overall, our data highly support advanced preclinical studies for the development of Esc(1-21)-1c as an efficacious therapeutic alternative against pulmonary P. aeruginosa infection
Efficient independent component analysis
Independent component analysis (ICA) has been widely used for blind source
separation in many fields such as brain imaging analysis, signal processing and
telecommunication. Many statistical techniques based on M-estimates have been
proposed for estimating the mixing matrix. Recently, several nonparametric
methods have been developed, but in-depth analysis of asymptotic efficiency has
not been available. We analyze ICA using semiparametric theories and propose a
straightforward estimate based on the efficient score function by using
B-spline approximations. The estimate is asymptotically efficient under
moderate conditions and exhibits better performance than standard ICA methods
in a variety of simulations.Comment: Published at http://dx.doi.org/10.1214/009053606000000939 in the
Annals of Statistics (http://www.imstat.org/aos/) by the Institute of
Mathematical Statistics (http://www.imstat.org
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