5,887 research outputs found
Demography, capital flows and unemployment
This paper contributes to the already vast literature on demography-induced international capital flows by examining the role of labor market imperfections and institutions. We setup a two-country overlapping generations model with search unemployment, which we calibrate on EU15 and US data. Labor market imperfections are found to significantly increase the volume of capital flows, because of stronger employment adjustments in comparison with a competitive economy. We next exploit themodel to investigate how demographic asymmetriesmay have contributed to unemployment and welfare changes in the recent past (1950-2010). We show that a policy reform in one country also has an impact on labor markets in other countries when capital is mobile.demographics; capital flows; overlapping generations; general equilibrium; unemployment
Demography, Capital Flows and Unemployment
This paper contributes to the already vast literature on demography-induced international capital flows by examining the role of labor market imperfections and institutions. We setup a two-country overlapping generations model with search unemployment, which we calibrate on EU15 and US data. Labor market imperfections are found to significantly increase the volume of capital flows, because of stronger employment adjustments in comparison with a competitive economy. We next exploit the model to investigate how demographic asymmetries may have contributed to unemployment and welfare changes in the recent past (1950-2010). We show that a policy reform in one country also has an impact on labor markets in other countries when capital is mobile.demographics, capital flows, overlapping generations, general equilibrium, unemployment
Vulnerability and Protection of Critical Infrastructures
Critical infrastructure networks are a key ingredient of modern society. We
discuss a general method to spot the critical components of a critical
infrastructure network, i.e. the nodes and the links fundamental to the perfect
functioning of the network. Such nodes, and not the most connected ones, are
the targets to protect from terrorist attacks. The method, used as an
improvement analysis, can also help to better shape a planned expansion of the
network.Comment: 4 pages, 1 figure, 3 table
Energy transfer dynamics and thermalization of two oscillators interacting via chaos
We consider the classical dynamics of two particles moving in harmonic
potential wells and interacting with the same external environment (HE),
consisting of N non-interacting chaotic systems. The parameters are set so that
when either particle is separately placed in contact with the environment, a
dissipative behavior is observed. When both particles are simultaneously in
contact with HE an indirect coupling between them is observed only if the
particles are in near resonance. We study the equilibrium properties of the
system considering ensemble averages for the case N=1 and single trajectory
dynamics for N large. In both cases, the particles and the environment reach an
equilibrium configuration at long times, but only for large N a temperature can
be assigned to the system.Comment: 8 pages, 6 figure
S = 3 Ground State for a Tetranuclear Mn^(IV)₄O₄ Complex Mimicking the S₃ State of the Oxygen Evolving Complex
The S₃ state is currently the last observable intermediate prior to O–O bond formation at the oxygen-evolving complex (OEC) of Photosystem II, and its electronic structure has been assigned to a homovalent Mn^(IV)₄ core with an S = 3 ground state. While structural interpretations based on the EPR spectroscopic features of the S₃ state provide valuable mechanistic insight, corresponding synthetic and spectroscopic studies on tetranuclear complexes mirroring the Mn oxidation states of the S₃ state remain rare. Herein, we report the synthesis and characterization by XAS and multifrequency EPR spectroscopy of a Mn^(IV)₄O₄ cuboidal complex as a spectroscopic model of the S₃ state. Results show that this Mn^(IV)₄O₄ complex has an S = 3 ground state with isotropic ⁵⁵Mn hyperfine coupling constants of −75, −88, −91, and 66 MHz. These parameters are consistent with an αααβ spin topology approaching the trimer–monomer magnetic coupling model of pseudo-octahedral Mn^(IV) centers. Importantly, the spin ground state changes from S = 1/2 to S = 3 as the OEC is oxidized from the S₂ state to the S₃ state. This same spin state change is observed following oxidation of the previously reported Mn^(III)Mn^(IV)₃O₄ cuboidal complex to the Mn^(IV)₄O₄ complex described here. This sets a synthetic precedent for the observed low-spin to high-spin conversion in the OEC
Demography, capital flows and unemployment
This paper contributes to the already vast literature on demography-induced international capital flows by examining the role of labor market imperfections and institutions. We setup a two-country overlapping generations model with search unemployment, which we calibrate on EU15 and US data. Labor market imperfections are found to significantly increase the volume of capital flows, because of stronger employment adjustments in comparison with a competitive economy. We next exploit themodel to investigate how demographic asymmetriesmay have contributed to unemployment and welfare changes in the recent past (1950-2010). We show that a policy reform in one country also has an impact on labor markets in other countries when capital is mobile.demographics; capital flows; overlapping generations; general equilibrium; unemployment
A Method to Find Community Structures Based on Information Centrality
Community structures are an important feature of many social, biological and
technological networks. Here we study a variation on the method for detecting
such communities proposed by Girvan and Newman and based on the idea of using
centrality measures to define the community boundaries (M. Girvan and M. E. J.
Newman, Community structure in social and biological networks Proc. Natl. Acad.
Sci. USA 99, 7821-7826 (2002)). We develop an algorithm of hierarchical
clustering that consists in finding and removing iteratively the edge with the
highest information centrality. We test the algorithm on computer generated and
real-world networks whose community structure is already known or has been
studied by means of other methods. We show that our algorithm, although it runs
to completion in a time O(n^4), is very effective especially when the
communities are very mixed and hardly detectable by the other methods.Comment: 13 pages, 13 figures. Final version accepted for publication in
Physical Review
Efficient Behavior of Small-World Networks
We introduce the concept of efficiency of a network, measuring how
efficiently it exchanges information. By using this simple measure small-world
networks are seen as systems that are both globally and locally efficient. This
allows to give a clear physical meaning to the concept of small-world, and also
to perform a precise quantitative a nalysis of both weighted and unweighted
networks. We study neural networks and man-made communication and
transportation systems and we show that the underlying general principle of
their construction is in fact a small-world principle of high efficiency.Comment: 1 figure, 2 tables. Revised version. Accepted for publication in
Phys. Rev. Let
Consumptive hypothyroidism in a patient with malignant rhabdoid tumor of the kidney: case report on a newly found association
Introduction: Consumptive hypothyroidism is a rare paraneoplastic condition most commonly associated with infantile hemangiomas. It is caused by overexpression of deiodinase type 3 (D3), which leads to preferential conversion of thyroxine to the metabolically inactive reverse triiodothyronine (rT3), paralleled by a decrease of the biologically active T3. Case presentation: A 46-year-old male patient with previously normal thyroid function was diagnosed with a renal carcinoma with rhabdoid differentiation. He was treated with sunitinib, followed by the immune checkpoint inhibitors ipilimumab and nivolumab, and he developed primary hypothyroidism secondary to thyroiditis. Substitution with unusually high doses of levothyroxine as high as 4.3 mu g/kg/day did not normalize his thyroid function. Poor compliance was refuted because there was no improvement after observed administration. He had no malabsorption. Although tyrosine kinase inhibitors can increase the expression of D3, this effect tends to be modest. Therefore, the suspicion of tumor-related consumptive hypothyroidism was raised and supported by low free T3 and elevated rT3 levels. The therapy could not be further modified because the patient opted for palliative care and passed away 12 days later.Immunohistochemistry of the tumor from a sample obtained prior to systemic therapy documented abundant expression of D3, corroborating the diagnosis of consumptive hypothyroidism. Conclusions: This observation extends the spectrum of malignancies overexpressing D3. Although rare, increased awareness of this paraneoplastic syndrome is key, if persistent hypothyroidism cannot be explained by compliance issues or malabsorption. Substitution with high doses of levothyroxine, and combination therapy with liothyronine, can correct hypothyroidism in these patients
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