Diagnostic Accuracy of Home Sleep Apnea Testing (HSAT) Based on Recording Duration

Introduction: Obstructive Sleep Apnea (OSA) is a chronic sleeping disorder with serious health consequences. Currently, standard diagnosis is through in-lab polysomnography; however, there has been a shift to greater use of Home Sleep Apnea Testing (HSAT) for patients with a high pre-test probability of having OSA. Objective: To investigate the minimum recording time needed during HSAT to accurately diagnose the presence and severity of OSA. Methods: A retrospective review was conducted of HSATs done from January-October 2017. Each study was divided into 1-, 2-,3-,4-,5-, 6-, and 7 hour intervals beginning at the recording start time. The respiratory event index (REI) was determined for each of these time intervals and then compared to the initial REI derived from the total monitoring time (REITMT) by a Fleiss’ κ test, a paired samples t-test, and concordance correlation coefficients (CCC). Results: Significant differences were found between the REITRT and the REI at 60 min (P \u3c 0.0001), 120 min (0.0002), 180 min (\u3c 0.0001) and 240 min (0.0002) with a lack of concordance, signifying these intervals are poor diagnostic correlates for the REITRT. REIs determined at 300, 360, and 420 min were not significantly different from the REITRT and had very significant CCCs, 0.979, 0.990, and 0.996, respectively. The Fleiss’ κ test showed almost perfect agreement between the REITRT and and the REI for 360 and 420 min. Discussion: The results suggest that at least 6 hours of monitoring time during HSAT is needed to accurrately diagnose and determine the severity of OSA

Real-time agreement and fulfilment of SLAs in Cloud Computing environments

A Cloud Computing system must readjust its resources by taking into account the demand for its services. This raises the need for designing protocols that provide the individual components of the Cloud architecture with the ability to self-adapt and to reach agreements in order to deal with changes in the services demand. Furthermore, if the Cloud provider has signed a Service Level Agreement (SLA) with the clients of the services that it offers, the appropriate agreement mechanism has to ensure the provision of the service contracted within a specified time. This paper introduces real-time mechanisms for the agreement and fulfilment of SLAs in Cloud Computing environments. On the one hand, it presents a negotiation protocol inspired by the standard WSAgreement used in web services to manage the interactions between the client and the Cloud provider to agree the terms of the SLA of a service. On the other hand, it proposes the application of a real-time argumentation framework for redistributing resources and ensuring the fulfilment of these SLAs during peaks in the service demand.This work is supported by the Spanish government Grants CONSOLIDER-INGENIO 2010 CSD2007-00022, TIN2011-27652-C03-01, TIN2012-36586-C03-01 and TIN2012-36586-C03-03.De La Prieta, F.; Heras Barberá, SM.; Palanca Cámara, J.; Rodríguez, S.; Bajo, J.; Julian Inglada, VJ. (2014). Real-time agreement and fulfilment of SLAs in Cloud Computing environments. 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Multiple determinants of lifespan memory differences

Memory problems are among the most common complaints as people grow older. Using structural equation modeling of commensurate scores of anterograde memory from a large (N = 315), population-derived sample (www.cam-can.org), we provide evidence for three memory factors that are supported by distinct brain regions and show differential sensitivity to age. Associative memory and item memory are dramatically affected by age, even after adjusting for education level and fluid intelligence, whereas visual priming is not. Associative memory and item memory are differentially affected by emotional valence, and the age-related decline in associative memory is faster for negative than for positive or neutral stimuli. Gray-matter volume in the hippocampus, parahippocampus and fusiform cortex, and a white-matter index for the fornix, uncinate fasciculus and inferior longitudinal fasciculus, show differential contributions to the three memory factors. Together, these data demonstrate the extent to which differential ageing of the brain leads to differential patterns of memory loss