426 research outputs found

    Frame functions in finite-dimensional Quantum Mechanics and its Hamiltonian formulation on complex projective spaces

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    This work concerns some issues about the interplay of standard and geometric (Hamiltonian) approaches to finite-dimensional quantum mechanics, formulated in the projective space. Our analysis relies upon the notion and the properties of so-called frame functions, introduced by A.M. Gleason to prove his celebrated theorem. In particular, the problem of associating quantum state with positive Liouville densities is tackled from an axiomatic point of view, proving a theorem classifying all possible correspondences. A similar result is established for classical observables representing quantum ones. These correspondences turn out to be encoded in a one-parameter class and, in both cases, the classical objects representing quantum ones result to be frame functions. The requirements of U(n)U(n) covariance and (convex) linearity play a central r\^ole in the proof of those theorems. A new characterization of classical observables describing quantum observables is presented, together with a geometric description of the C∗C^*-algebra structure of the set of quantum observables in terms of classical ones.Comment: 32 pages, no figure, fixed some coefficients and added some comments and references, accepted for publication in Int. J. Geom. Methods. Mod. Phy

    Possible Treatments of Atypical Parkinsonism

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    Success in treating patients with atypical parkinsonism remains exceedingly low. It is particularly important for both neurologists and general practitioners to have a guideline in the actual possible cure options. This study reviews the limited available literature reporting treatment trials about treatment in parkinsonism. Various therapeutical approaches have been tried with rasagiline, immunoglobulin, autologous mesenchymal stem cells, davunetide, lithium, and tideglusib. Recently, transdermal rotigotine (RTG) has been proposed for the treatment of atypical parkinsonism, as well as deep brain stimulation (DBS) of the pedunculopontine nucleus (PPN) alone or combined with globus pallidus internus (Gpi) stimulation. The outcomes reviewed here highlight the need for the development of randomized, placebo-controlled trials to validate outcomes about rotigotine, DBS, and all other new therapies directed at altering the underlying biological mechanisms involved in the disease process

    Diritto al lavoro e servizio pubblico di collocamento

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    Nella analisi si propone una riflessione sul ruolo dei servizi pubblici per l'impiego e sulla tipologia di servizi offerti, con l'intento anche di suggerire nuovi modi di operare in un sistema rafforzato dei servizi per il lavoro in Italia, che tenta di fornire risposte significative all'occupazione giovanile, agevolando il passaggio dalla scuola al lavoro. Questo lavoro analizza anche gli effetti delle agenzie di collocamento sul mercato del lavoro stesso, e il numero di agenzie che influenza l’efficienza dei meccanismi di incontro tra domanda e offerta di lavoro. In più si verificano le varie problematiche del mercato del lavoro e si mostrano le asimetrie informative. Infine viene illustrata, alla luce della sua complessa evoluzione, la vigente disciplina del collocamento per evidenziare il profondo mutamento, rispetto al sistema delineato dalla legge n. 264/1949, della sua funzione, e delle relative strutture organizzative, delle quali si illustra sinteticamente la disciplina ed il funzionamento

    Epidemiology and costs of hospital care for COPD in Puglia

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    BACKGROUND AND AIMS: Chronic obstructive pulmonary disease (COPD) is currently the 5(th )cause of morbidity and mortality in the developed world and represents a substantial economic and social burden. The aim of this study is to report on hospital admissions and related costs of hospital treatment for COPD in the Puglia Region of Italy in the years 2005-2007. MATERIALS AND METHODS: Patients were selected who were hospitalized between 01/01/2005 and 31/12/2007 with ICD-9-CM code: 490.xx: bronchitis not specified as acute or chronic; 491.xx: chronic bronchitis; 492.xx: emphysema; 493.xx: asthma; 494.xx: bronchiectasis; 496.xx: chronic airway obstruction not elsewhere classified; 518.81: acute respiratory failure as principal or secondary diagnosis. RESULTS: In the period 2005-2007, there were 73,721 hospital admissions for COPD registered in Puglia (25,690 in 2005; 24,153 in 2006 and 23,878 in 2007) of which 34.3% were women, with no significant variation in the three years. There appears to be a negative trend in hospitalisations in Puglia for chronic bronchitis with ratios decreasing from 359.4 per 100,000 population in 2005 to 307.9 per 100,000 in 2007. The overall cost of COPD for Apulian hospital trusts was €272,293,182.85 over the 3-year period. CONCLUSIONS: Analysis of the data for hospital care, its costs and performance may be an important indicator of the efficacy of community care. In particular, the lack of reduction in admissions for COPD should lead decision makers to question both the appropriateness and quality of the care given

    Behavioral and Neurophysiological Effects of Transdermal Rotigotine in Atypical Parkinsonism

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    Effective therapies for the so-called atypical parkinsonian syndrome (APS) such as multiple system atrophy (MSA), progressive supranuclear palsy (PSP), or corticobasal syndrome (CBS) are not available. Dopamine agonists (DA) are not often used in APS because of inefficacy and in a minority of case, their side effects, like dyskinesias, impairment of extrapyramidal symptoms or the appearance of psychosis, and REM sleep behavioral disorders (RBD). Transdermal rotigotine (RTG) is a non-ergot dopamine agonist indicated for use in early and advanced Parkinson’s disease with a good tolerability and safety. Moreover, its action on a wide range of dopamine receptors, D1, D2, D3, unlike other DA, could make it a good option in APS, where a massive dopamine cell loss is documented. In this pilot, observational open-label study we evaluate the efficacy and tolerability of RTG in patients affected by APS. Thirty-two subjects with diagnosis of APS were treated with transdermal RTG. APS diagnosis was: MSA parkinsonian type (MSA-P), MSA cerebellar type (MSA-C), PSP, and CBS. Patients were evaluated by UPDRS-III, neuropsychiatric inventory, mini mental state examination at baseline, and after 6, 12, and 18 months. The titration schedule was maintained very flexible, searching the major clinical effect and the minor possible adverse events (AEs) at each visit. AEs were recorded. APS patients treated with RTG show an overall decrease of UPDRS-III scores without increasing behavioral disturbances. Only three patients were dropped out of the study. Main AEs were hypotension, nausea, vomiting, drowsiness, and tachycardia. The electroencephalographic recording power spectra analysis shows a decrease of theta and an increase of low alpha power. In conclusion, transdermal RTG seems to be effective and well tolerated in APS patients

    Comparison of the effects of transdermal and oral rivastigmine on cognitive function and EEG markers in patients with Alzheimer’s disease

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    Background: Alzheimer's disease (AD) is the most common cause of dementia in older patients. Rivastigmine (RV, Exelon®, Novartis), a reversible cholinesterase inhibitor, improves clinical manifestations of AD and may enhance ACh-modulated electroencephalogram (EEG) alpha frequency. This pilot study aimed to determine the effects of two formulations of RV (transdermal patch [TV-RDP] and oral capsules [TV-CP]) on alpha frequency, in particular the posterior dominant rhythm, and cognitive function (assessed by the Mini-Mental State Examination [MMSE]) in patients with AD.Methods: Subjects with AD were assigned to receive either RV-TDP 10 cm2 or RV-CP 12 mg/day. All patients underwent EEG recordings at the beginning and end of the 18-month study period using P3, P4, O1 and O2 electrodes, each at high (10.5–13.0 Hz) and low (8.0–10.5 Hz) frequency. MMSE scores were determined at the start of the study (T0) and at three successive 6-month intervals (T1, T2 and T3).Results: RV-TDP administration (n=10) maintained cognitive function as evidenced by stable MMSE scores from baseline to 18 months (21.07 ± 2.4 to 21.2 ± 3.1) compared with a decrease in MMSE score with RV-CP (n=10) over 18 months (18.3 ± 3.6 to 13.6 ± 5.06 [adjusted for covariates p=0.006]). MMSE scores were significantly different between treatment groups from 6 months (p=0.04). RV-TDP also increased the spectral power of alpha waves in the posterior region measured with electrode P3 in a significantly great percentage of patients than TV-CP from baseline to 18 months; 80% versus 30%, respectively (p=0.025 [χ2 test]).Conclusion: RV-TDP was associated with a greater proportion of patients with increased posterior region alpha wave spectral power and significantly higher cognitive function at 18 months, compared with RV-CP treatment. Our findings suggest that RV-TDP provides an effective long-term management option in patients with AD compared with oral RV-CP. This study is a pilot, open-label study with

    Plasma Technology Reduces Blood Loss in Adolescent Idiopathic Scoliosis Surgery: A Prospective Randomized Clinical Trial

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    Study Design: Prospective randomized clinical trial. Objectives: To assess the effectiveness of PEAK Plasmablade (PPB), compared with bipolar sealer and standard electrocautery, in the posterior spinal instrumentation and fusion (PSF) surgery performed for adolescent idiopathic scoliosis (AIS). Methods: Ninety-three patients undergoing PSF surgery for AIS were randomized in 2 groups: group-A patients (n = 45) underwent PSF surgery using PPB; group-B patients (n = 48) were treated with bipolar sealer and standard electrocautery. Demographic and surgical data was recorded. All the patients underwent serial blood tests on the day before surgery (T0) and at 24 (T1), 48 (T2), 72 (T3), and 96 (T4) hours postoperatively. Visual analogue scale for pain (VAS) score, the percentage of paracetamol assumption, and the blood transfusion rate were recorded in the time-lapse T1 to T4. Intergroup variability was assessed. Pearson correlation test was performed. A P value <.05 was considered significant. Results: In group A, a significantly shorter total operative time ( P = .0087), a significantly lower total intraoperative blood loss (TBL) ( P = .001), and a higher postoperative hemoglobin (Hb) ( P = .01) were recorded. A significant higher mean Hb concentration and mean albumin value was recorded in group A at 24 and 48 hours postoperatively. A significant correlation between TBL and hospital stay was recorded in both groups (group A, P = .00 001; group B, P = .00 006); moreover, in both groups, a significant correlation was observed between TBL and mean VAS at 72 hours postoperatively (group A, P = .0009; group B, P = .0001) and at 96 hours postoperatively (group A, P = .000 044; group B, P = .00 001). Conclusions: PPB reduces the intraoperative blood loss in PSF performed for AIS, thus allowing a patient's faster recovery

    Anatomical Substrate and Scalp EEG Markers are Correlated in Subjects with Cognitive Impairment and Alzheimer's Disease

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    Dementia is a syndromic diagnosis, encompassing various stage of severity and different anatomo-physiological substrates. The hippocampus is one of the first and most affected brain regions affected by both Alzheimer's disease (AD) and mild cognitive impairment (MCI). Moreover, chronic cerebrovascular disease (CVD) is one of the major risk factor for developing dementia. Recent studies have demonstrated different relationship between the anatomical substrate and scalp electroencephalography (EEG) markers. Indeed, modifications of EEG rhythmicity is not proportional to the hippocampal atrophy, whereas changes in EEG activity are directly proportional to the load of subcortical CVD. The computation of the EEG spectral power and the analysis of the functional coupling of brain areas, through linear coherence, are two of the most known processing methods in EEG research. Two specific EEG markers, theta/gamma and alpha3/alpha2 frequency ratio have been reliable associated to the atrophy of amygdalo–hippocampal complex. Moreover, theta/gamma ratio has been related to MCI conversion in dementia and alpha3/alpha2 ratio has been specifically related to MCI conversion in AD. The functional coupling of brain areas is also modulated by hippocampal atrophy. In the MCI subjects, hippocampal atrophy is linked to an increase of interhemispheric coherence seen on frontal and temporal regions whereas subcortical CVD is linked to a decrease of coherence in fronto-parietal regions. In the present study the most significant results of recent studies on correlation between scalp EEG, cognitive decline, and anatomical substrate have been reviewed, with particular attention to the relationships between EEG changes and hippocampal atrophy. The following review is not intended to provide a comprehensive summary of the literature. Rather it identifies and discusses selected studies that are designed to find the specific correlation between scalp EEG markers and anatomo-pathological substrate. The principal aim is to propose a plausible neurophysiological theoretical model of the cognitive decline as mirrored by both structural and functional tools of research
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