403 research outputs found

    Generalized Complex Spherical Harmonics, Frame Functions, and Gleason Theorem

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    Consider a finite dimensional complex Hilbert space \cH, with dim(\cH) \geq 3, define \bS(\cH):= \{x\in \cH \:|\: ||x||=1\}, and let \nu_\cH be the unique regular Borel positive measure invariant under the action of the unitary operators in \cH, with \nu_\cH(\bS(\cH))=1. We prove that if a complex frame function f : \bS(\cH)\to \bC satisfies f \in \cL^2(\bS(\cH), \nu_\cH), then it verifies Gleason's statement: There is a unique linear operator A: \cH \to \cH such that f(u)=f(u) = for every u \in \bS(\cH). AA is Hermitean when ff is real. No boundedness requirement is thus assumed on ff {\em a priori}.Comment: 9 pages, Accepted for publication in Ann. H. Poincar\'

    Hospitalisation for COPD in Puglia: the role of hospital discharge database to estimate prevalence and incidence

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    Background and aim. Chronic Obstructive Pulmonary Disease (COPD), although largely preventable, is a great health burden in all the countries worldwide. Statistics of morbidity and mortality of COPD show the need for correct management of the disease. Chronic Obstructive Respiratory Diseases (DRG 88) are in 9th place for discharge in in-patient hospital admission. It is necessary to establish specific indicators which are efficacious and relevant for the patient, the doctor and the health manager. This study will analyse the information in respect of hospital admissions (Hospital discharge database) in Puglia for the period 2000-2005. Methods. The analysis was carried out utilising the Puglia Region hospital patient discharge database, selecting those patients with admission for chronic respiratory disease as principal or secondary diagnosis. Results. Chronic respiratory diseases are more frequent in males and in people over 45 years old with frequency increasing with age. Geographical distribution shows that there are greater rates of hospitalisation in big cities and in the neighbourhood of industrial areas. Although the trend over time is slight. A higher percentage of re-admission has been found for patients with COPD, and the interval between the two admissions occurs within one or two months; the diagnosis at the second admission is the same as for the first. 10.6% of discharge forms report one diagnosis, especially in patients older than 65 years of age. Little could be said about diagnostic procedures because these are not reported on the discharge form. Conclusion. Hospitalisation data confirms expectations regarding age and sex of patients. The high hospitalisation rates indicate that in-patients care still remains the only viable treatment for COPD and other chronic respiratory diseases. The high number of exacerbations reflect the absence of out-patients service or community care, and the same diagnosis in more than one episode shows the lack of efficiency of health services and disease management. This data is necessary to understand disease distribution and the modification of disease management in order to reduce health care costs, to increase efficacy in disease control and to limit repeated exacerbation and so to obtain the maximum benefit for the patients

    Epidemiology of Pulmonary Embolism in Apulia from analysis of current data

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    Background and aims. Pulmonary embolism (PE) is a relatively common cardiovascular emergency: present evidence suggests that PE is the third most acute cardiovascular disease after cardiac ischemic syndromes and stroke. The aim of this study is to evaluate hospital admissions for PE in the Apulia Region of Italy in the period 2001-2007 through an analysis of the Apulia Region hospital patient discharge database. Methods. Patients were selected on the basis of admissions between 01/01/2001 and 31/12/2007 with ICD-9-CM code of 415.11 (Iatrogenic pulmonary embolism and infarction) or 415.19 (Other pulmonary embolism and infarction) as principal or secondary diagnosis. Results. The number of patients selected from the database was 4,303. The raw annual admission data shows an increasing trend from 13.9x100,000 residents in 2001 to 18.9x100,000 residents in 2007. The average patient age was 68.7 years and 59% were females and 41%. There were 470 deaths in hospital (10.9% of patients). Conclusions. PE is associated with much health care and a substantial economic burden, yet many PE and general venous thromboembolism (VTE) events are preventable. It remains the responsibility of individual hospitals to identify specific areas in which they can improve their VTE prophylaxis rates to obtain positive results from the reporting initiatives and incentive programs

    Anti-Trypanosoma cruzi effects of cyclosporin A derivatives: possible role of a P-glycoprotein and parasite cyclophilins

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    Cyclophilins are target molecules for cyclosporin A (CsA), an immunosuppressive antimicrobial drug. We have previously reported the in vitro anti-Trypanosoma cruzi activity of H-7-94 and F-7-62 non-immunosuppressive CsA analogues. In this work, we continue the study of the parasiticidal effect of H-7-94 and F-7-62 CsA analogues in vitro and in vivo and we analyse 3 new CsA derivatives: MeIle-4-CsA (NIM 811), MeVal-4-CsA (MeVal-4) and D-MeAla-3-EtVal-4-CsA, (EtVal-4). The most efficient anti-T. cruzi effect was observed with H-7-94, F-7-62 and MeVal-4 CsA analogues evidenced as inhibition of epimastigote proliferation, trypomastigote penetration, intracellular amastigote development and in vivo T. cruzi infection. This trypanocidal activity could be due to inhibition of the peptidyl prolyl cis-trans isomerase activity on the T. cruzi recombinant cyclophilins tested. Furthermore, CsA and F-7-62 derivative inhibited the efflux of rhodamine 123 from T. cruzi epimastigotes, suggesting an interference with a P-glycoprotein activity. Moreover, H-7-94 and F-7-62 CsA analogues were not toxic as shown by cell viability and by aminopyrine-N-demethylase activity on mammalian cells. Our results show that H-7-94, F-7-62 and MeVal-4 CsA analogues expressed the highest inhibiting effects on T. cruzi, being promissory parasiticidal drugs worthy of further studie

    Quantum Inequalities for the Electromagnetic Field

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    A quantum inequality for the quantized electromagnetic field is developed for observers in static curved spacetimes. The quantum inequality derived is a generalized expression given by a mode function expansion of the four-vector potential, and the sampling function used to weight the energy integrals is left arbitrary up to the constraints that it be a positive, continuous function of unit area and that it decays at infinity. Examples of the quantum inequality are developed for Minkowski spacetime, Rindler spacetime and the Einstein closed universe.Comment: 19 pages, 1 table and 1 figure. RevTex styl

    United classification of cosmic gamma-ray bursts and their counterparts

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    United classification of gamma-ray bursts and their counterparts is established on the basis of measured characteristics: photon energy E and emission duration T. The founded interrelation between the mentioned characteristics of events consists in that, as the energy increases, the duration decreases (and vice versa). The given interrelation reflects the nature of the phenomenon and forms the E-T diagram, which represents a natural classification of all observed events in the energy range from 10E9 to 10E-6 eV and in the corresponding interval of durations from about 10E-2 up to 10E8 s. The proposed classification results in the consequences, which are principal for the theory and practical study of the phenomenon.Comment: Keywords Gamma rays: burst

    Enhancement of the electron electric dipole moment in gadolinium garnets

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    Effects caused by the electron electric dipole moment (EDM) in gadolinium garnets are considered. Experimental studies of these effects could improve current upper limit on the electron EDM by several orders of magnitude. We suggest a consistent theoretical model and perform calculations of observable effects in gadolinium gallium garnet and gadolinium iron garnet. Our calculation accounts for both direct and exchange diagrams.Comment: 9 page

    Global distribution of a key trophic guild contrasts with common latitudinal diversity patterns

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    Most hypotheses explaining the general gradient of higher diversity toward the equator are implicit or explicit about greater species packing in the tropics. However, global patterns of diversity within guilds, including trophic guilds (i.e., groups of organisms that use similar food resources), are poorly known. We explored global diversity patterns of a key trophic guild in stream ecosystems, the detritivore shredders. This was motivated by the fundamental ecological role of shredders as decomposers of leaf litter and by some records pointing to low shredder diversity and abundance in the tropics, which contrasts with diversity patterns of most major taxa for which broad-scale latitudinal patterns haven been examined. Given this evidence, we hypothesized that shredders are more abundant and diverse in temperate than in tropical streams, and that this pattern is related to the higher temperatures and lower availability of high-quality leaf litter in the tropics. Our comprehensive global survey (129 stream sites from 14 regions on six continents) corroborated the expectedlatitudinal pattern and showed that shredder distribution (abundance, diversity and assemblage composition) was explained by a combination of factors, including water temperature (some taxa were restricted to cool waters) and biogeography (some taxa were more diverse in particular biogeographic realms). In contrast to our hypothesis, shredder diversity was unrelated to leaf toughness, but it was inversely related to litter diversity. Our findings markedly contrast with global trends of diversity for most taxa, and with the general rule of higher consumer diversity at higher levels of resource diversity. Moreover, they highlight the emerging role of temperature in understanding global patterns of diversity, which is of great relevance in the face of projected global warming. © 2011 by the Ecological Society of America.Peer Reviewe
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