702 research outputs found
A critical review of child maltreatment indices: Psychometric properties and application in the South African context
The public and academic focus on child maltreatment and neglect and their prevention has spawned a range of surveillance instruments and mechanisms intended to identify child maltreatment and measure its magnitude. While such surveillance responses are obviously important for the prevention and management of child maltreatment and neglect, there appears to have been insufficient attention directed at examining their utility in the South Africa context. A review hereof is likely to offer insights to programme planners and child safety advocates working to mobilise political and community-level actions. Accordingly, the paper considers a sample of child maltreatment scales and measures and critically evaluates them in terms of their psychometric properties, as well as their application value for South Africa. Review findings indicate that despite an obvious lack of evaluative standards for assessing the psychometric properties of child maltreatment measures, those considered in this review appear to perform well with the study populations and in cross-cultural applications. It is suggested that following an appraisal of their linguistic and cultural appropriateness, and the adoption of suitable piloting procedures, the identified scales could be applied in South Africa with confidence in their measurement capabilities.Keywords: review, child maltreatment and neglect, indices, cross-cultural application, South Afric
XPySom: High-performance self-organizing maps
In this paper, we introduce XPySom, a new open-source Python implementation of the well-known Self-Organizing Maps (SOM) technique. It is designed to achieve high performance on a single node, exploiting widely available Python libraries for vector processing on multi-core CPUs and GP-GPUs. We present results from an extensive experimental evaluation of XPySom in comparison to widely used open-source SOM implementations, showing that it outperforms the other available alternatives. Indeed, our experimentation carried out using the Extended MNIST open data set shows a speed-up of about 7x and 100x when compared to the best open-source multi-core implementations we could find with multi-core and GP-GPU acceleration, respectively, achieving the same accuracy levels in terms of quantization error
Behavioral analysis for virtualized network functions: A som-based approach
In this paper, we tackle the problem of detecting anomalous behaviors in a virtualized infrastructure for network function virtualization, proposing to use self-organizing maps for analyzing historical data available through a data center. We propose a joint analysis of system-level metrics, mostly related to resource consumption patterns of the hosted virtual machines, as available through the virtualized infrastructure monitoring system, and the application-level metrics published by individual virtualized network functions through their own monitoring subsystems. Experimental results, obtained by processing real data from one of the NFV data centers of the Vodafone network operator, show that our technique is able to identify specific points in space and time of the recent evolution of the monitored infrastructure that are worth to be investigated by a human operator in order to keep the system running under expected conditions
Using Self-Organizing Maps for the Behavioral Analysis of Virtualized Network Functions
Detecting anomalous behaviors in a network function virtualization infrastructure is of the utmost importance for network operators. In this paper, we propose a technique, based on Self-Organizing Maps, to address such problem by leveraging on the massive amount of historical system data that is typically available in these infrastructures. Indeed, our method consists of a joint analysis of system-level metrics, provided by the virtualized infrastructure monitoring system and referring to resource consumption patterns of the physical hosts and the virtual machines (or containers) that run on top of them, and application-level metrics, provided by the individual virtualized network functions monitoring subsystems and related to the performance levels of the individual applications. The implementation of our approach has been validated on real data coming from a subset of the Vodafone infrastructure for network function virtualization, where it is currently employed to support the decisions of data center operators. Experimental results show that our technique is capable of identifying specific points in space (i.e., components of the infrastructure) and time of the recent evolution of the monitored infrastructure that are worth to be investigated by human operators in order to keep the system running under expected conditions
An assessment of prevalence and expenditure associated with discharge brain MRI in preterm infants
To assess national expenditure associated with preterm-infant brain MRI and potential impact of reduction per Choosing Wisely campaign 2015 recommendation to âavoid routine screening term-equivalent or discharge brain MRIs in preterm-infantsâ. Cross-sectional U.S. trend data from the Agency for Healthcare Research and Quality (AHRQ), Healthcare Cost and Utilization Project (HCUP) Kidsâ Inpatient Database (KID) database (2006, 2009, 2012, 2016) was used to estimate overall national expenditure associated with brain MRI among infants with gestational age (GA) â€36 weeks, and also when classified as ânot indicatedâ (NI-MRI) i.e., equivalent to routine use without clinical indications and regarded as low-value service (LVS). Associated cost was determined by querying CMS-database for physician-fee-schedules to find the highest global procedure-cost per cycle, then adjusting for inflation. Sensitivity-analyses were conducted to account for additional clinical charges associated with NI-MRI. 3,768 (0.26%) of 1,472,236 preterm-infants had brain MRI across all cycles (inflation-adjusted total 1,299,130 (95% CI: 1,610,755); 2009, 873,487, 931,836 (95% CI: 1,197,156); and 2016, 172,061, 1,190,919/1.2 million
VIRTUAL DIVING IN THE UNDERWATER ARCHAEOLOGICAL SITE OF CALA MINNOLA
The paper presents the application of the technologies and methods defined in the VISAS project for the case study of the underwater archaeological site of Cala Minnola located in the island of Levanzo, in the archipelago of the Aegadian Islands (Sicily, Italy). The VISAS project (http://visas-project.eu) aims to improve the responsible and sustainable exploitation of the Underwater Cultural Heritage by means the development of new methods and technologies including an innovative virtual tour of the submerged archaeological sites. In particular, the paper describes the 3D reconstruction of the underwater archaeological site of Cala Minnola and focus on the development of the virtual scene for its visualization and exploitation. The virtual dive of the underwater archaeological site allows users to live a recreational and educational experience by receiving historical, archaeological and biological information about the submerged exhibits, the flora and fauna of the place
The Longitudinal Association Between Physical Activity and Physical Function in Older Women
PurposeThe age-related decline in physical function is ameliorated by physical activity; however, less is known about changes in physical function in active vs. inactive older women. The purpose of this study was to determine the longitudinal associations between physical activity and physical function in community-dwelling older women.Methods238 participants (age 79.0 ± 5.1) were dichotomized into two activity groups [inactive (IG); n = 144 or active (AG); n = 94] based on self-reported exercise at baseline. Repeated measures ANCOVA, controlling for age, measured differences in physical function between activity groups at baseline and 48-months using the Timed Up and Go, 30-s chair stand, and 30-second arm curl. Differences in Timed Up and Go classification [normal (†8.23 s); preclinical limitations/limited physical function (>8.23 s)] were analyzed using chi-square tests for activity group and for activity-age group (AG, <80 years; AG, â„ 80 years; IG, <80 years; IG, â„ 80 years).ResultsThe repeated measures ANCOVA yielded a significant main effect for activity group for the Timed Up and Go (p = 0.006), 30-s chair stand (p = 0.002) and 30 s arm curl (p = 0.007) and a significant time main effect for the Timed Up and Go (p = 0.016). There were no significant group by time interactions. A larger proportion of the IG than the AG (58.2 vs. 86.5%, respectively) had Timed Up and Go scores >8.23 s (p < 0.001). At 48-months, individuals in the AG were more likely to have normal Timed Up and Go scores compared to those in the IG in both age groups [Ï(3, N=236)2 = 42.56, p < 0.001].ConclusionOlder women who engaged in regular exercise at baseline had higher levels of objectively measured physical function and were less likely to have abnormal Timed Up and Go scores. These findings help illustrate the long-term benefit of exercise on physical function in older women
High-resolution tSZ cartography of clusters of galaxies with NIKA at the IRAM 30-m telescope
The thermal Sunyaev-Zeldovich effect (tSZ) is a powerful probe to study
clusters of galaxies and is complementary with respect to X-ray, lensing or
optical observations. Previous arcmin resolution tSZ observations ({\it e.g.}
SPT, ACT and Planck) only enabled detailed studies of the intra-cluster medium
morphology for low redshift clusters (). Thus, the development of
precision cosmology with clusters requires high angular resolution observations
to extend the understanding of galaxy cluster towards high redshift. NIKA2 is a
wide-field (6.5 arcmin field of view) dual-band camera, operated at and containing KID (Kinetic Inductance Detectors), designed to
observe the millimeter sky at 150 and 260 GHz, with an angular resolution of 18
and 12 arcsec respectively. The NIKA2 camera has been installed on the IRAM
30-m telescope (Pico Veleta, Spain) in September 2015. The NIKA2 tSZ
observation program will allow us to observe a large sample of clusters (50) at
redshift ranging between 0.5 and 1. As a pathfinder for NIKA2, several clusters
of galaxies have been observed at the IRAM 30-m telescope with the NIKA
prototype to cover the various configurations and observation conditions
expected for NIKA2.Comment: Proceedings of the 28th Texas Symposium on Relativistic Astrophysics,
Geneva, Switzerland, December 13-18, 201
High angular resolution Sunyaev-Zel'dovich observations of MACS J1423.8+2404 with NIKA: Multiwavelength analysis
The prototype of the NIKA2 camera, NIKA, is an instrument operating at the
IRAM 30-m telescope, which can observe simultaneously at 150 and 260GHz. One of
the main goals of NIKA2 is to measure the pressure distribution in galaxy
clusters at high resolution using the thermal SZ (tSZ) effect. Such
observations have already proved to be an excellent probe of cluster pressure
distributions even at high redshifts. However, an important fraction of
clusters host submm and/or radio point sources, which can significantly affect
the reconstructed signal. Here we report on <20" resolution observations at 150
and 260GHz of the cluster MACSJ1424, which hosts both radio and submm point
sources. We examine the morphology of the tSZ signal and compare it to other
datasets. The NIKA data are combined with Herschel satellite data to study the
SED of the submm point source contaminants. We then perform a joint
reconstruction of the intracluster medium (ICM) electronic pressure and density
by combining NIKA, Planck, XMM-Newton, and Chandra data, focusing on the impact
of the radio and submm sources on the reconstructed pressure profile. We find
that large-scale pressure distribution is unaffected by the point sources
because of the resolved nature of the NIKA observations. The reconstructed
pressure in the inner region is slightly higher when the contribution of point
sources are removed. We show that it is not possible to set strong constraints
on the central pressure distribution without accurately removing these
contaminants. The comparison with X-ray only data shows good agreement for the
pressure, temperature, and entropy profiles, which all indicate that MACSJ1424
is a dynamically relaxed cool core system. The present observations illustrate
the possibility of measuring these quantities with a relatively small
integration time, even at high redshift and without X-ray spectroscopy.Comment: 15 pages, 17 figures, submitted to A&
- âŠ