696 research outputs found
Master equations for effective Hamiltonians
We reelaborate on a general method for obtaining effective Hamiltonians that
describe different nonlinear optical processes. The method exploits the
existence of a nonlinear deformation of the su(2) algebra that arises as the
dynamical symmetry of the original model. When some physical parameter (usually
related to the dispersive limit) becomes small, we immediately get a diagonal
effective Hamiltonian that represents correctly the dynamics for arbitrary
states and long times. We apply the same technique to obtain how the noise
terms in the original model transform under this scheme, providing a systematic
way of including damping effects in processes described in terms of effective
Hamiltonians.Comment: 10 pages, no figure
Optimality and distortionary lobbying: regulating tobacco consumption
We examine policies directed at regulating tobacco consumption through three types of instruments: (i) an excise tax hindering consumption by increasing the price of cigarettes, (ii) prevention programs helping consumers to make choices that are more time consistent when trading-off the current pleasure from smoking and its future health harms, and (iii) smoking bans directly restricting consumption. First, on normative grounds, we focus on the optimal design of public policies maximizing the economy’s surplus. Second, in a positive perspective, we investigate how the lobbying activities of the tobacco industry, of smokers, and of anti-tobacco organizations may distort government intervention
Characterization and outcomes of 414 patients with primary SS who developed haematological malignancies
Objective: To characterize 414 patients with primary SS who developed haematological malignancies and to analyse how the main SS- and lymphoma-related features can modify the presentation patterns and outcomes. Methods: By January 2021, the Big Data Sjögren Project Consortium database included 11 966 patients fulfilling the 2002/2016 classification criteria. Haematological malignancies diagnosed according to the World Health Organization (WHO) classification were retrospectively identified. Results: There were 414 patients (355 women, mean age 57 years) with haematological malignancies (in 43, malignancy preceded at least one year the SS diagnosis). A total of 376 (91%) patients had mature B-cell malignancy, nearly half had extranodal marginal zone lymphoma (MZL) of mucosa-associated lymphoid tissue (MALT lymphoma) (n = 197), followed by diffuse large B-cell lymphoma (DLBCL) (n = 67), nodal MZL lymphoma (n = 29), chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) (n = 19) and follicular lymphoma (FL) (n = 17). Rates of complete response, relapses and death were 80%, 34% and 13%, respectively, with a 5-year survival rate of 86.5% after a mean follow-up of 8 years. There were significant differences in age at diagnosis (younger in MALT, older in CLL/SLL), predominant clinical presentation (glandular enlargement in MALT lymphoma, peripheral lymphadenopathy in nodal MZL and FL, constitutional symptoms in DLBCL, incidental diagnosis in CLL/SLL), therapeutic response (higher in MALT lymphoma, lower in DLBCL) and survival (better in MALT, nodal MZL and FL, worse in DLBCL). Conclusion: In the largest reported study of haematological malignancies complicating primary SS, we confirm the overwhelming predominance of B-cell lymphomas, especially MALT, with the salivary glands being the primary site of involvement. This highly-specific histopathological scenario is linked with the overall good prognosis with a 5-year survival rate of nearly 90%
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