Limit theorems for Lévy flights on a 1D Lévy random medium

We study a random walk on a point process given by an ordered array of points (ωk, k ∈ Z) on the real line. The distances ωk+1 − ωk are i.i.d. random variables in the domain of attraction of a β-stable law, with β ∈ (0, 1) ∪ (1, 2). The random walk has i.i.d. jumps such that the transition probabilities between ωk and ωℓ depend on ℓ − k and are given by the distribution of a Z-valued random variable in the domain of attraction of an α-stable law, with α ∈ (0, 1) ∪ (1, 2). Since the defining variables, for both the random walk and the point process, are heavy-tailed, we speak of a Lévy flight on a Lévy random medium. For all combinations of the parameters α and β, we prove the annealed functional limit theorem for the suitably rescaled process, relative to the optimal Skorokhod topology in each case. When the limit process is not càdlàg, we prove convergence of the finite-dimensional distributions. When the limit process is deterministic, we also prove a limit theorem for the fluctuations, again relative to the optimal Skorokhod topology

Risk adjustment for inter-hospital comparison of caesarean delivery rates in low-risk deliveries

BACKGROUND: Caesarean delivery (CD) rates have been frequently used as quality measures for maternity service comparisons. More recently, primary CD rates (CD in women without previous CD) or CD rates within selected categories such as nulliparous, term, cephalic singleton deliveries (NTCS) have been used. The objective of this study is to determine the extent to which risk adjustment for clinical and socio-demographic variables is needed for inter-hospital comparisons of CD rates in women without previous CD and in NTCS deliveries. METHODS: Hospital discharge records of women who delivered in Emilia-Romagna Region (Italy) from January, 2007 to June 2009 and in Tuscany Region for year 2009 were linked with birth certificates. Adjusted RRs of CD in women without a previous Caesarean and NTCS were estimated using Poisson regression. Percentage differences in RR before and after adjustment were calculated and hospital rankings, based on crude and adjusted RRs, were examined. RESULTS: Adjusted RR differed substantially from crude RR in women without a previous Caesarean and only marginally in NTCS group. Hospital ranking was markedly affected by adjustment in women without a previous CD, but less in NTCS. CONCLUSION: Risk adjustment is warranted for inter-hospital comparisons of primary CD rates but not for NTCS CD rates. Crude NTCS CD rates are a reliable estimate of adjusted NTCS CD

Socio-Economic and Clinical Factors as Predictors of Disease Evolution and Acute Events in COPD Patients

BACKGROUND: Socio-economic, cultural and environmental factors are becoming increasingly important determinants of chronic obstructive pulmonary disease (COPD). We conducted a study to investigate socio-demographic, lifestyle and clinical factors, and to assess their role as predictors of acute events (mortality or hospitalization for respiratory causes) in a group of COPD patients. METHODS: Subjects were recruited among outpatients who were undertaking respiratory function tests at the Pneumology Unit of the Sant'Orsola-Malpighi Hospital, Bologna. Patients were classified according to the GOLD Guidelines. RESULTS: 229 patients with COPD were included in the study, 44 with Mild, 68 Moderate, 52 Severe and 65 Very Severe COPD (GOLD stage). Significant differences among COPD stage, in terms of smoking status and fragility index, were detected. COPD stage significantly affected the values of all clinical tests (spirometry and ABG analysis). Kaplan-Meier estimates showed a significant difference between survival curves by COPD stage with lower event-free probability in very severe COPD stage. Significant risk factors for acute events were: underweight (HR = 4.08; 95% CI 1.01-16.54), having two or more comorbidities (HR = 4.71; 95% CI 2.52-8.83), belonging to moderate (HR = 3.50; 95% CI 1.01-12.18) or very severe COPD stage (HR = 8.23; 95% CI 2.35-28.85). CONCLUSIONS: Our findings indicate that fragility is associated with COPD stage and that comorbidities and the low body mass index are predictors of mortality or hospitalization. Besides spirometric analyses, FeNO measure and comorbidities, body mass index could also be considered in the management and monitoring of COPD patients

Migrant pathways to community mental health centres in Italy.

Background: Many studies indicate that migrants in western countries have limited access to and low utilization of community mental health centres (CMHCs) despite the high prevalence of mental disorders. Aims: We aimed to compare migrant pathways to care across four CMHCs located in different Italian provinces and to identify pathway to care predictors. Methods: Migrants attending the four CMHCs between 1 July 1999 and 31 December 2007 were included in the study. Data were gathered retrospectively from clinical data sets and chart review. Results: Five hundred and eleven (511) migrants attended the four CMHCs, 61% were referred by GPs or other health services and 39% followed non-medical pathways to care (self-referral or through social and voluntary organizations), with important site variations. Younger age and being married were predictors of medical pathways to care; lacking a residence permit and having a diagnosis of substance abuse were related to non-medical pathways. Conclusions: Pathways to CMHCs are complex and influenced by many factors. Non-medical pathways to care seem to be frequent among migrants in Italy. More attention should be paid to developing psychiatric consultation liaison models that also encompass the social services and voluntary organizations

Migrant pathways to community mental health centres in Italy.

Background: Many studies indicate that migrants in western countries have limited access to and low utilization of community mental health centres (CMHCs) despite the high prevalence of mental disorders. Aims: We aimed to compare migrant pathways to care across four CMHCs located in different Italian provinces and to identify pathway to care predictors. Methods: Migrants attending the four CMHCs between 1 July 1999 and 31 December 2007 were included in the study. Data were gathered retrospectively from clinical data sets and chart review. Results: Five hundred and eleven (511) migrants attended the four CMHCs, 61% were referred by GPs or other health services and 39% followed non-medical pathways to care (self-referral or through social and voluntary organizations), with important site variations. Younger age and being married were predictors of medical pathways to care; lacking a residence permit and having a diagnosis of substance abuse were related to non-medical pathways. Conclusions: Pathways to CMHCs are complex and influenced by many factors. Non-medical pathways to care seem to be frequent among migrants in Italy. More attention should be paid to developing psychiatric consultation liaison models that also encompass the social services and voluntary organizations

Validation of techniques to mitigate copper surface contamination in CUORE

In this article we describe the background challenges for the CUORE experiment posed by surface contamination of inert detector materials such as copper, and present three techniques explored to mitigate these backgrounds. Using data from a dedicated test apparatus constructed to validate and compare these techniques we demonstrate that copper surface contamination levels better than 10E-07 - 10E-08 Bq/cm2 are achieved for 238U and 232Th. If these levels are reproduced in the final CUORE apparatus the projected 90% C.L. upper limit on the number of background counts in the region of interest is 0.02-0.03 counts/keV/kg/y depending on the adopted mitigation technique.Comment: 10 pages, 6 figures, 6 table

The low energy spectrum of TeO2 bolometers: results and dark matter perspectives for the CUORE-0 and CUORE experiments

We collected 19.4 days of data from four 750 g TeO2 bolometers, and in three of them we were able to set the energy threshold around 3 keV using a new analysis technique. We found a background rate ranging from 25 cpd/keV/kg at 3 keV to 2 cpd/keV/kg at 25 keV, and a peak at 4.7 keV. The origin of this peak is presently unknown, but its presence is confirmed by a reanalysis of 62.7 kg.days of data from the finished CUORICINO experiment. Finally, we report the expected sensitivities of the CUORE0 (52 bolometers) and CUORE (988 bolometers) experiments to a WIMP annual modulation signal.Comment: 9 pages, 10 figure

Risk adjustment for inter-hospital comparison of primary cesarean section rates: need, validity and parsimony

BACKGROUND: Cesarean section rates is often used as an indicator of quality of care in maternity hospitals. The assumption is that lower rates reflect in developed countries more appropriate clinical practice and general better performances. Hospitals are thus often ranked on the basis of caesarean section rates. The aim of this study is to assess whether the adjustment for clinical and sociodemographic variables of the mother and the fetus is necessary for inter-hospital comparisons of cesarean section (c-section) rates and to assess whether a risk adjustment model based on a limited number of variables could be identified and used. METHODS: Discharge abstracts of labouring women without prior cesarean were linked with abstracts of newborns discharged from 29 hospitals of the Emilia-Romagna Region (Italy) from 2003 to 2004. Adjusted ORs of cesarean by hospital were estimated by using two logistic regression models: 1) a full model including the potential confounders selected by a backward procedure; 2) a parsimonious model including only actual confounders identified by the "change-in-estimate" procedure. Hospital rankings, based on ORs were examined. RESULTS: 24 risk factors for c-section were included in the full model and 7 (marital status, maternal age, infant weight, fetopelvic disproportion, eclampsia or pre-eclampsia, placenta previa/abruptio placentae, malposition/malpresentation) in the parsimonious model. Hospital ranking using the adjusted ORs from both models was different from that obtained using the crude ORs. The correlation between the rankings of the two models was 0.92. The crude ORs were smaller than ORs adjusted by both models, with the parsimonious ones producing more precise estimates. CONCLUSION: Risk adjustment is necessary to compare hospital c-section rates, it shows differences in rankings and highlights inappropriateness of some hospitals. By adjusting for only actual confounders valid and more precise estimates could be obtained

CUORE-0 detector: design, construction and operation

The CUORE experiment will search for neutrinoless double-beta decay of$^{130}$Te with an array of 988 TeO$_2$ bolometers arranged in 19 towers.CUORE-0, the first tower assembled according to the CUORE procedures, was builtand commissioned at Laboratori Nazionali del Gran Sasso, and took data fromMarch 2013 to March 2015. In this paper we describe the design, constructionand operation of the CUORE-0 experiment, with an emphasis on the improvementsmade over a predecessor experiment, Cuoricino. In particular, we demonstratewith CUORE-0 data that the design goals of CUORE are within reach