Search results for "USA"
showing 10 items of 3178 documents
Physical Activity Is Related with Cartilage Quality in Women with Knee Osteoarthritis
2017
Purpose To study the relationship between 12-month leisure-time physical activity (LTPA) level and changes in estimated biochemical composition of tibiofemoral cartilage in postmenopausal women with mild knee osteoarthritis (OA). Methods Originally, 87 volunteer postmenopausal women, age 60 to 68 yr, with mild knee OA (Kellgren Lawrence I/II and knee pain) participated in a randomized controlled, 4-month aquatic training trial (RCT), after which 76 completed the 12-month postintervention follow-up period. Self-reported LTPA was collected along the 12-month period using a diary from which MET task hours per month were calculated. Participants were divided into MET task hour tertiles: 1, lowe…
Association between radiography-based subchondral bone structure and MRI-based cartilage composition in postmenopausal women with mild osteoarthritis
2016
Summary Objective Our aim was to investigate the relation between radiograph-based subchondral bone structure and cartilage composition assessed with delayed gadolinium enhanced magnetic resonance imaging of cartilage (dGEMRIC) and T 2 relaxation time. Design Ninety-three postmenopausal women (Kellgren–Lawrence grade 0: n = 13, 1: n = 26, 2: n = 54) were included. Radiograph-based bone structure was assessed using entropy of the Laplacian-based image ( E Lap ) and local binary patterns ( E LBP ), homogeneity indices of the local angles (HI Angles,mean , HI Angles,Perp , HI Angles,Paral ), and horizontal (FD Hor ) and vertical fractal dimensions (FD Ver ). Mean dGEMRIC index and T 2 relax…
Il Castello Maniace di Siracusa. Stereotomia e tecniche costruttive nell’architettura del Mediterraneo
2011
L’enigma del castello Maniace di Siracusa, realizzato nella prima metà del XIII secolo per volontà dell’imperatore Federico II, ruota intorno all’immensa sala colonnare, alla sua funzione e ai criteri costruttivi adottati per edificarla. L’autrice ha avuto l’opportunità di studiare capillarmente la fabbrica, assumendo una conoscenza materica diretta, grazie alla lunga frequentazione, resa possibile dal cantiere di restauro che ha recentemente restituito il “monumento” alla fruizione pubblica. Queste informazioni sono state utilizzate per verificare le diverse letture e ipotesi sinora formulate e l’indagine procede a partire dalla densa serie di quesiti inevasi. Di fronte a una architettura …
THE SEMANTIC NETWORK OF THE LATIN PREPOSITION PER: A DIACHRONIC INVESTIGATION
2020
Proponiamo qui i risultati di uno studio corpus-based sugli slittamenti diacronici osservabili nel network semantico della preposizione per in latino. Sulla base della Cognitive Grammar, descriviamo la semantica di per situandola lungo un continuum che procede dal concreto all’astratto, a partire da un contenuto schematico originario; discutiamo, quindi, i percorsi attraverso i quali i nuovi significati astratti emergono attraverso sli ttamenti metonimici, focalizzando la nostra attenzione sui ruoli causali e sulla caratteristica di animatezza.
Assessing complexity and causality in heart period variability through a model-free data-driven multivariate approach
2017
The aim of this study is to emphasize the importance of model-free data-driven mul- tivariate approaches in describing HP variability and cardiovascular control mechanisms responsible for inducing HP changes via modifications of different cardiovascular vari- ables such as SAP and RESP. The goal was achieved through the application, a previously proposed model-free data-driven multivariate framework devised to assess complexity and causality over a multivariate set composed by several, simultaneously recorded, car- diovascular variability series (Porta et al., 2014). The approach was applied to assess the complexity of the cardiac control, through the evaluation of the amount of irregularit…
Assessing connectivity in the presence of instantaneous causality
2014
This chapter is devoted to a discussion of the impact of instantaneous causality on the computation of frequency domain connectivity measures. Instantaneous causality (IC) refers to interactions between two observed time series which occur within the same time lag.
Analytic structure ofϕ4theory using light-by-light sum rules
2013
Abstract We apply a sum rule for the forward light-by-light scattering process within the context of the ϕ 4 quantum field theory. As a consequence of the sum rule a stringent causality criterion is presented and the resulting constraints are studied within a particular resummation of graphs. Such resummation is demonstrated to be consistent with the sum rule to all orders of perturbation theory. We furthermore show the appearance of particular non-perturbative solutions within such approximation to be a necessary requirement of the sum rule. For a range of values of the coupling constant, these solutions manifest themselves as a physical bound state and a K-matrix pole. For another domain …
Linear and nonlinear parametric model identification to assess granger causality in short-term cardiovascular interactions
2008
We assessed directional relationships between short RR interval and systolic arterial pressure (SAP) variability series according to the concept of Granger causality. Causality was quantified as the predictability improvement (PI) of a time series obtained when samples of the other series were used for prediction, i.e. moving from autoregressive (AR) to AR exogenous (ARX) prediction. AR and ARX predictions were performed both by linear and nonlinear parametric models. The PIs of RR given SAP and of SAP given RR, measuring baroreflex and mechanical couplings, were calculated in 15 healthy subjects in the resting supine and upright tilt positions. Using nonlinear models we found a bilateral i…
Causality and the Coulomb sum rule in nuclei.
1989
The spectral function in the Jost-Lehmann-Dyson representation of causal commutators is determined for the nonrelativistic limit of inclusive lepton scattering from nuclei. From this an extrapolation of the Coulomb sum rule to higher-momentum transfers is performed which is consistent with the requirement of causality.
Causality and Localization Operators
2005
The evolution of the expectation values of one and two points scalar field operators and of positive localization operators, generated by an istantaneous point source is non local. Non locality is attributed either to zero point vacuum fluctuations, or to non local operations or to the microcausality principle being no satisfied.