Search results for "causa."
showing 10 items of 647 documents
Measuring postural-related changes of spontaneous baroreflex sensitivity after repeated long-duration diving: Frequency domain approaches
2012
Sustained water immersion is thought to modulate orthostatic tolerance to an extent dependent on the duration and repetition over consecutive days of the diving sessions. We tested this hypothesis investigating in ten healthy subjects the potential changes in the cardiovascular response to head-up tilt induced by single and multiple resting air dives. Parametric cross-spectral analysis of spontaneous RR interval and systolic arterial pressure variability was performed in three experimental sessions: before diving (BD), after single 6-hour dive (ASD), and after multiple 6-hour dives (AMD, 5 consecutive days with 18-hour surface interval). From this analysis, baroreflex sensitivity (BRS) was …
Birth weight and adult income : An examination of mediation through adult height and body mass
2021
This paper examines the causal links between early human endowments and socioeconomic outcomes in adulthood. We use a genotyped longitudinal survey (Cardiovascular Risk in Young Finns Study) that is linked to the administrative registers of Statistics Finland. We focus on the effect of birth weight on income via two anthropometric mediators: body mass index (BMI) and height in adulthood. We find that (i) the genetic instruments for birth weight, adult height, and adult BMI are statistically powerful; (ii) there is a robust total effect of birth weight on income for men but not for women; (iii) the total effect of birth weight on income for men is partly mediated via height but not via BMI; …
Mixed predictability and cross-validation to assess non-linear Granger causality in short cardiovascular variability series
2006
A method to evaluate the direction and strength of causal interactions in bivariate cardiovascular and cardiorespiratory series is presented. The method is based on quantifying self and mixed predictability of the two series using nearest-neighbour local linear approximation. It returns two causal coupling indexes measuring the relative improvement in predictability along direct and reverse directions, and a directionality index indicating the preferential direction of interaction. The method was implemented through a cross-validation approach that allowed quantification of directionality without constraining the embedding of the series, and fully exploited the available data to maximise th…
Direct and Indirect Effects of Function in Associated Variables Such as Depression and Severity on Pain Intensity in Women with Carpal Tunnel Syndrome
2015
Objective To determine the direct and indirect effects of function on clinical variables such as age, pain intensity, years of the disease, severity of symptoms, and depression in women with electrodiagnostic and clinical diagnosis of carpal tunnel syndrome (CTS). Design A cross-sectional study. Setting Patients from an urban hospital referred to a university clinic. Methods Two hundred and forty-four (n = 224) women with CTS were included. Demographic and clinical data, duration of symptoms, function, symptom's severity of the symptoms, pain intensity, and depression were self-reported collected. Correlation and path analysis with maximum likelihood estimation were conducted to assess the …
Evidence of unbalanced regulatory mechanism of heart rate and systolic pressure after acute myocardial infarction
2002
The interactions between systolic arterial pressure (SAP) and R-R interval (RR) fluctuations after acute myocardial infarction (AMI) were investigated by measures of synchronization separating the feedback from the feedforward control and capturing both linear and nonlinear contributions. The causal synchronization, evaluating the ability of RR to predict SAP (χs/t) or vice versa (χt/s), and the global synchronization (χ) were estimated at rest and after head-up tilt in 35 post-AMI patients, 20 young and 12 old. Significance and nonlinearity of the coupling were assessed by surrogate data analysis. Tilting increased the number of young subjects in which RR-SAP link was significant (from 17…
Oocyte donation outcome after oncological treatment in cancer survivors.
2012
Objective To study reproductive outcome in patients cured of cancer who required oocyte donation (OD) owing to iatrogenic ovarian dysfunction. Design Multicenter, unmatched, retrospective cohorts study. Setting Private, university-affiliated group of clinics. Patient(s) Women treated and cured of cancer (n = 142) who underwent 333 cycles of OD (exposed group) and women without a previous cancer diagnosis (n = 17,844) who underwent 29,778 cycles of OD (unexposed cohort) between January 2000 and January 2012. Intervention(s) Retrospective chart review. Main Outcome Measure(s) Pregnancy, implantation, miscarriage, and ongoing pregnancy rates. Result(s) There were no differences in terms of pre…
Assessing Causality in normal and impaired short-term cardiovascular regulation via nonlinear prediction methods
2009
We investigated the ability of mutual nonlinear prediction methods to assess causal interactions in short-term cardiovascular variability during normal and impaired conditions. Directional interactions between heart period (RR interval of the ECG) and systolic arterial pressure (SAP) short-term variability series were quantified as the cross-predictability (CP) of one series given the other, and as the predictability improvement (PI) yielded by the inclusion of samples of one series into the prediction of the other series. Nonlinear prediction was performed through global approximation (GA), approximation with locally constant models (LA0) and approximation with locally linear models (LA1) …
Healthcare-associated infections over an eight year period in a large university hospital in Sicily (Italy, 2011–2018)
2021
Background: Up to 7% of hospitalised patients acquire at least one healthcare-associated infection (HAI). The aim of the present study was to quantify the burden of HAIs in an Italian hospital, identifying involved risk factors. Methods: Prevalence point study carried out from 2011 to 2018. For each recruited patient, a data entry form was compiled including information on demographics, hospital admission, risk factors, antimicrobial treatment, and infection if present. Results: A total of 2844 patients were included and 218 (7.03%) reported an infection. HAI prevalence rates showed a significant increase (average annual per cent change (AAPC) +33.9%; p=0.018) from 2011 to 2014 whereas from…
An Agent-Based Model of Extortion Racketeering
2016
Mafias can be considered as criminal organisations that are in the business of producing, promoting, and selling protection. Here, we describe the Palermo Scenario, an agent-based model of protection rackets aimed to deepen our understanding of protection rackets, and help policymakers to evaluate methods for destabilising them. Additionally, since the system is explicitly specified, we can use it to investigate the entire causal pathway from cause to effect: not only from actions to Mafia destabilisation, but also the intermediate actions along the path and actors' internal mental representations among the population.
Modeling Radicalization and Violent Extremism
2020
Given public anxiety about radicalization and violent extremism, it is not surprising that these topics have grabbed the attention of so many scholars in recent years. However, some have expressed concern over the fact that only a few studies in this relatively new field contain empirical data or systematic data analysis or develop causal models of the mechanisms generating these phenomena. We believe that computational modeling and simulation techniques can make a significant contribution to this scientific literature and eventually provide new tools for improving policy analysis. Here we briefly describe (1) an integrative theory of violent extremism proposed by Kruglanski and colleagues …