425 research outputs found
From IRAP to CBIT: tax distortions and redistributive effects
The paper explores the differences between IRAP (the Regional Tax on Productive Activities) and CBIT (the Comprehensive Business Income Tax), which approximately corresponds to allow the deduction of labor cost from the taxable base of IRAP. By developing a DSGE model that ncorporates business taxes, like IRAP or CBIT, we find that tax distortions due to IRAP are more contractionary than those caused by the presence of CBIT. Empirically, tax revenues and redistributive effects are more carefully analyzed. We implement a microsimulation model (MSM) based on a dataset of more than 150,000 incorporated firms. We show that small incorporated firms are particularly harmed by IRAP, especially when business run a loss instead of a profit. This is due to the fact that IRAP is a business tax on value added, which does not allow for the deduction of labor cost. For this purpose, we focus on the introduction of a reform based on the CBIT principle. Our result is that CBIT is particularly costly and more able to enhance the profitability for larger enterprises. Moreover, the tax design of CBIT is more regressive compared to the IRAP including tax allowances. Consequently, an efficiency-equity trade-off between IRAP and CBIT might be emphasizedbusiness cycles, tax distortions, micro-simulations models, distributive effects, Italy.
Weak ergodicity breaking of receptor motion in living cells stemming from random diffusivity
Molecular transport in living systems regulates numerous processes underlying
biological function. Although many cellular components exhibit anomalous
diffusion, only recently has the subdiffusive motion been associated with
nonergodic behavior. These findings have stimulated new questions for their
implications in statistical mechanics and cell biology. Is nonergodicity a
common strategy shared by living systems? Which physical mechanisms generate
it? What are its implications for biological function? Here, we use single
particle tracking to demonstrate that the motion of DC-SIGN, a receptor with
unique pathogen recognition capabilities, reveals nonergodic subdiffusion on
living cell membranes. In contrast to previous studies, this behavior is
incompatible with transient immobilization and therefore it can not be
interpreted according to continuous time random walk theory. We show that the
receptor undergoes changes of diffusivity, consistent with the current view of
the cell membrane as a highly dynamic and diverse environment. Simulations
based on a model of ordinary random walk in complex media quantitatively
reproduce all our observations, pointing toward diffusion heterogeneity as the
cause of DC-SIGN behavior. By studying different receptor mutants, we further
correlate receptor motion to its molecular structure, thus establishing a
strong link between nonergodicity and biological function. These results
underscore the role of disorder in cell membranes and its connection with
function regulation. Due to its generality, our approach offers a framework to
interpret anomalous transport in other complex media where dynamic
heterogeneity might play a major role, such as those found, e.g., in soft
condensed matter, geology and ecology.Comment: 27 pages, 5 figure
Gold catalyzed heterocyclization processes.
The work done in the present doctoral thesis, developed in the GlaxoSmithKline Medicine Research Center Laboratories and in collaboration with the Insubria University of Como, was focused on heterocyclization processes in organic chemistry catalyzed by gold. This metal confirmed its interesting carbophylic properities of activating double and triple carbon-carbon bonds toward various nucleophiles both in inter-and intramolecular way. Three main topics are mainly covered in this work. The first concerns gold catalyzed intramolecular hydroamination of \u3b1-aminoallenamides for the preparation of 2-vinylimidazolidinones by means of nucleophilic attack of the amino group on the inside double bond of the diene moiety. This is the first example of gold catalyzed cyclization on allene substrates bearing an amido group which however resulted inactive.
The second topic deals with the development of a simple procedure for the intramolecular hydroarylation of N-alkynyl pyrrole-2-carboxamide accomplished by gold(III)-catalysis. The outcome of the reaction led to differently substituted bicyclic pyrrolo-fused products arising either from direct cylization or from a formal rearrangement of the carboxamide group. The substrates containing a propargyl group afforded pyrrolo[2,3-c]pyridine and pyrrolo[3,2-c]pyridine derivatives in a ratio depending on the reaction solvent. When bearing a phenyl group at the C-C triple bond, the pyrrolylamides furnished pyrrolo[2,3-c]azepines and pyrrolo[3,2-c]azepines which ratio depends once again on the used solvent.
The last but not the least is aimed on the development of an efficient gold-catalyzed procedure to synthesize 2-alkylidene-3,4-dihydro-2H-1,4-benzoxazines starting from 2-alkynyl-substitued phenols. This is an intramolecular hydroalkoxylation reaction on alkynes tethered to a phenol moiety that represents a valuable alternative to already reported transition-metal-catalyzed procedures
Gold catalyzed heterocyclization processes.
The work done in the present doctoral thesis, developed in the GlaxoSmithKline Medicine Research Center Laboratories and in collaboration with the Insubria University of Como, was focused on heterocyclization processes in organic chemistry catalyzed by gold. This metal confirmed its interesting carbophylic properities of activating double and triple carbon-carbon bonds toward various nucleophiles both in inter-and intramolecular way. Three main topics are mainly covered in this work. The first concerns gold catalyzed intramolecular hydroamination of α-aminoallenamides for the preparation of 2-vinylimidazolidinones by means of nucleophilic attack of the amino group on the inside double bond of the diene moiety. This is the first example of gold catalyzed cyclization on allene substrates bearing an amido group which however resulted inactive.
The second topic deals with the development of a simple procedure for the intramolecular hydroarylation of N-alkynyl pyrrole-2-carboxamide accomplished by gold(III)-catalysis. The outcome of the reaction led to differently substituted bicyclic pyrrolo-fused products arising either from direct cylization or from a formal rearrangement of the carboxamide group. The substrates containing a propargyl group afforded pyrrolo[2,3-c]pyridine and pyrrolo[3,2-c]pyridine derivatives in a ratio depending on the reaction solvent. When bearing a phenyl group at the C-C triple bond, the pyrrolylamides furnished pyrrolo[2,3-c]azepines and pyrrolo[3,2-c]azepines which ratio depends once again on the used solvent.
The last but not the least is aimed on the development of an efficient gold-catalyzed procedure to synthesize 2-alkylidene-3,4-dihydro-2H-1,4-benzoxazines starting from 2-alkynyl-substitued phenols. This is an intramolecular hydroalkoxylation reaction on alkynes tethered to a phenol moiety that represents a valuable alternative to already reported transition-metal-catalyzed procedures
Mukaiyama-Michael vinylogous additions to nitroalkenes under solvent-free conditions
Abstract
The first Mukaiyama-Michael vinylogous reaction of a dioxinone-derived silyl ether to nitroalkenes is reported. The conjugate addition is performed in absence of any catalyst under solvent-free conditions, proceeding with satisfactory efficiency with variously substituted nitroalkenes.
Moreover, the first organocatalyzed Mukaiyama-Michael vinylogous reaction of trimethylsilyloxyfuran to nitroalkenes is described.The reaction is promoted by Brønsted acids under solvent-free conditions, taking place in moderate to good yield with variously substituted nitroalkenes.
Primary Sjögren’s Syndrome in the Elderly: Does Age of Onset Make a Difference?
Primary Sjögren’s syndrome (pSS) is a relatively common disease and one of the most common rheumatic diseases of autoimmune and inflammatory origin. It is primarily associated with symptoms of dryness, mainly in the mouth and eyes, but it can also manifest in the internal organs. Epidemiological studies have highlighted that elderly-onset pSS (EOpSS) is common, and it is known that sicca syndrome is a feature often observed in the elderly and can be induced by several factors. However, the presence of autoantibodies in older patients with sicca syndrome can be age-related and does not mean pSS is present. This review article presents the most important elements for making a correct diagnosis of EOpSS and considers clinical and/or laboratory differences between older and younger pSS patients. According to data from the literature, EOpSS is not a distinct subset of disease when compared with younger-onset pSS
Broadband plasmonic nanoantennas for multi-color nanoscale dynamics in living cells
Recently, the implementation of plasmonic nanoantennas has opened new
possibilities to investigate the nanoscale dynamics of individual biomolecules
in living cell. However, studies have yet been restricted to single molecular
species as the narrow wavelength resonance of gold-based nanostructures
precludes the simultaneous interrogation of different fluorescently labeled
molecules. Here we exploited broadband aluminum-based nanoantennas carved at
the apex of near-field probes to resolve nanoscale-dynamic molecular
interactions on intact living cell membranes. Through multicolor excitation, we
simultaneously recorded fluorescence fluctuations of dual-color labeled
transmembrane receptors known to form nanoclusters in living cells.
Fluorescence cross-correlation studies revealed transient interactions between
individual receptors in regions of ~60 nm. Moreover, the high
signal-to-background ratio provided by the antenna illumination allowed us to
directly detect fluorescent bursts arising from the passage of individual
receptors underneath the antenna. Remarkably, by reducing the illumination
volume below the characteristic receptor nanocluster sizes, we resolved
molecular diffusion within nanoclusters and distinguished it from nanocluster
diffusion. Spatiotemporal characterization of transient interactions between
molecules is crucial to understand how they communicate with each other to
regulate cell function. Our work demonstrates the potential of broadband
photonic antennas to study multi-molecular events and interactions in living
cell membranes with unprecedented spatiotemporal resolution
The effects of probiotics and prebiotics on the fatty acid profile and conjugated linoleic acid content of fermented cow milk
The ability of probiotic bacteria (Lactobacillus acidophilus La5 and Bifidobacterium animalis Bb12), to produce conjugated linoleic acid (CLA) in association with Streptococcus thermophilus and Lb. bulgaricus during milk fermentation has been evaluated in this study. Pasteurized cow milk and infant formula were used. Infant formula was selected for its high linoleic acid content, for being a source of CLA and for its prebiotic compounds, e.g. galacto-oligosaccharides. The microorganisms were not able to increase the CLA content of the fermented products under the given experimental conditions. No statistically significant differences (p>0.05) occurred between the CLA content in milk and the fermented samples. The CLA contents of 10 commercial fermented milk products were determined. The highest CLA content was observed in fermented milk containing only Str. thermophilus and Lb. bulgaricus. © 2015 Informa UK Ltd. All rights reserved
From IRAP to CBIT: tax distortions and redistributive effects
The paper explores the differences between IRAP (the Regional Tax on Productive Activities) and CBIT (the Comprehensive Business Income Tax), which approximately corresponds to allow the deduction of labor cost from the taxable base of IRAP. By developing a DSGE model that ncorporates business taxes, like IRAP or CBIT, we find that tax distortions due to IRAP are more contractionary than those caused by the presence of CBIT. Empirically, tax revenues and redistributive effects are more carefully
analyzed. We implement a microsimulation model (MSM) based on a dataset of more than 150,000 incorporated firms. We show that small incorporated firms are particularly harmed by IRAP, especially when business run a loss instead of a profit. This is due to the fact that IRAP is a business tax on value added, which does not allow for the deduction of labor cost. For this purpose, we focus on the introduction of a reform based on the CBIT principle. Our result is that CBIT is particularly costly and more able to enhance the profitability for larger enterprises. Moreover, the tax design of CBIT is more regressive compared to the IRAP including tax allowances. Consequently, an efficiency-equity trade-off between
IRAP and CBIT might be emphasize
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