Clinical endpoints for the study of geographic atrophy secondary to age-related macular degeneration

Purpose: To summarize the recent literature describing the application of modern technologies in the study of patients with geographic atrophy (GA) secondary to age-related macular degeneration. Methods: Review of the literature describing the terms and definitions used to describe GA, imaging modalities used to capture and measure GA, and the tests of visual function and functional deficits that occur in patients with GA. Results: In this paper, we describe the evolution of the definitions used to describe GA. We compare imaging modalities used in the characterization of GA, report on the sensitivity and specificity of the techniques where data exist, and describe the correlations between these various modes of capturing the presence of GA. We review the functional tests that have been used in patients with GA, and critically examine their ability to detect and quantify visual deficits. Conclusion: Ophthalmologists and retina specialists now have a wide range of assessments available for the functional and anatomic characterization of GA in patients with age-related macular degeneration. To date, studies have been limited by their unimodal approach, and we recommend that future studies of GA use multimodal imaging. We also suggest strategies for the optimal functional testing of patients with GA

Prevalence and causes of vision loss in Latin America and the Caribbean in 2015: magnitude, temporal trends and projections

OBJECTIVE: To estimate the prevalence and causes of blindness and vision impairment for distance and near in Latin America and the Caribbean (LAC) in 2015, and to forecast trends to 2020. METHODS: A meta-analysis from a global systematic review of cross-sectional, population-representative studies from published and unpublished sources from 1980 to 2014 included in the Global Vision Database. RESULTS: In 2015, across LAC, we estimate age-standardised prevalence to be 0.38% in all ages and 1.56% in those over age 50 for blindness, 2.06% in all ages and 7.86% in those over age 50 for moderate and severe vision impairment (MSVI), 1.89% in all ages and 6.93% in those over age 50 for mild vision impairment, and 39.59% in all ages and 45.27% in those over 50 for near vision impairment. We estimate that in 2015, 123.26 million persons were vision impaired; of those 2.34 million blind, 12.46 million with MSVI, 11.34 million mildly impaired and 97.12 million had near vision impairment. Cataract is the most common cause of blindness. Under- corrected refractive-error is the most common cause of vision impairment. CONCLUSIONS: Increasing granularity in prevalence estimates across all levels of vision loss suggest that one in five persons across LAC had some degree of vision loss in 2015. The absolute numbers of persons with vision impairment are increasing, while the age-standardised prevalence is decreasing. All countries should conduct epidemiologic studies to establish accurate national estimates and trends of vision impairment. Universal eye health services must be included in universal health coverage reforms to address fragmentation and segmentation of health care across the region

International nosocomial infection control consortium (INICC) report, data summary of 36 countries, for 2004-2009

The results of a surveillance study conducted by the International Nosocomial Infection Control Consortium (INICC) from January 2004 through December 2009 in 422 intensive care units (ICUs) of 36 countries in Latin America, Asia, Africa, and Europe are reported. During the 6-year study period, using Centers for Disease Control and Prevention (CDC) National Healthcare Safety Network (NHSN; formerly the National Nosocomial Infection Surveillance system [NNIS]) definitions for device-associated health care-associated infections, we gathered prospective data from 313,008 patients hospitalized in the consortium's ICUs for an aggregate of 2,194,897 ICU bed-days. Despite the fact that the use of devices in the developing countries' ICUs was remarkably similar to that reported in US ICUs in the CDC's NHSN, rates of device-associated nosocomial infection were significantly higher in the ICUs of the INICC hospitals; the pooled rate of central line-associated bloodstream infection in the INICC ICUs of 6.8 per 1,000 central line-days was more than 3-fold higher than the 2.0 per 1,000 central line-days reported in comparable US ICUs. The overall rate of ventilator-associated pneumonia also was far higher (15.8 vs 3.3 per 1,000 ventilator-days), as was the rate of catheter-associated urinary tract infection (6.3 vs. 3.3 per 1,000 catheter-days). Notably, the frequencies of resistance of Pseudomonas aeruginosa isolates to imipenem (47.2% vs 23.0%), Klebsiella pneumoniae isolates to ceftazidime (76.3% vs 27.1%), Escherichia coli isolates to ceftazidime (66.7% vs 8.1%), Staphylococcus aureus isolates to methicillin (84.4% vs 56.8%), were also higher in the consortium's ICUs, and the crude unadjusted excess mortalities of device-related infections ranged from 7.3% (for catheter-associated urinary tract infection) to 15.2% (for ventilator-associated pneumonia). Copyright © 2012 by the Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved

Analysis of a Queueing Model with Batch Markovian Arrival Process and General Distribution for Group Clearance

In this paper we consider a single server queueing model with under general bulk service rule with infinite upper bound on the batch size which we call group clearance. The arrivals occur according to a batch Markovian point process and the services are generally distributed. The customers arriving after the service initiation cannot enter the ongoing service. The service time is independent on the batch size. First, we employ the classical embedded Markov renewal process approach to study the model. Secondly, under the assumption that the services are of phase type, we study the model as a continuous-time Markov chain whose generator has a very special structure. Using matrix-analytic methods we study the model in steady-state and discuss some special cases of the model as well as representative numerical examples covering a wide range of service time distributions such as constant, uniform, Weibull, and phase type. © 2020, Springer Science+Business Media, LLC, part of Springer Nature

Experimental Investigation of Cavity-Induced Oscillations in Confined Supersonic Flow

acoustic oscillations exhibited by confined supersonic flow past a rectangular cavity of varying length-to dept

Investigation of the effect of acoustic oscillations on swirl flow using PIV

39th AIAA Fluid Dynamics Conference