Background Pediatric hematology-oncology (PHO) patients are at significant risk for developing central line-associated bloodstream infections (CLA-BSIs) due to their prolonged dependence on such catheters. Effective strategies to eliminate these preventable infections are urgently needed. In this study, we investigated the implementation of bundled central line maintenance practices and their effect on hospital-acquired CLA-BSIs. Materials and Methods CLA-BSI rates were analyzed within a single-institution’s PHO unit between January 2005 and June 2011. In May 2008, a multidisciplinary quality improvement team developed techniques to improve the PHO unit’s safety culture and implemented the use of catheter maintenance practices tailored to PHO patients. Data analysis was performed using time-series methods to evaluate the pre- and post-intervention effect of the practice changes. Results The pre-intervention CLA-BSI incidence was 2.92 per 1000-patient days (PD) and coagulase-negative Staphylococcus was the most prevalent pathogen (29%). In the post-intervention period, the CLA-BSI rate decreased substantially (45%) to 1.61 per 1000-PD (p<0.004). Early on, blood and marrow transplant (BMT) patients had a three-fold higher CLA-BSI rate compared to non-BMT patients (p<0.033). With additional infection control countermeasures added to the bundled practices, BMT patients experienced a larger CLA-BSI rate reduction such that BMT and non-BMT CLA-BSI rates were not significantly different post-intervention. Conclusions By adopting and effectively implementing uniform maintenance catheter care practices, learning multidisciplinary teamwork, and promoting a culture of patient safety, the CLA-BSI incidence in our study population was significantly reduced and maintained.

No abstract

No abstract

This paper presents the results of a recent three-dimensional (3D) survey at the Drimolen Makondo palaeontological deposits in the Hominid Sites of South Africa UNESCO World Heritage site. The Drimolen Makondo is a palaeokarstic feature that consists of a heavily eroded 2.6-2.0 Ma fossil-bearing palaeocave remnant. With photogrammetry and a laser scan survey, two 3D site models were created, georectified, and imported into geographical information system software. This paper outlines both of these survey techniques and provides an assessment of the relevant merits of each method and their applicability for detailed recording and archival documentation of palaeokarstic palaeontological and archaeological sites. Given the complex depositional context of many of the fossil-bearing South African cave systems and their importance for understanding our evolutionary history, new methods are critical to visualising and analysing 3D spatial data. The utility of 3D models lies in their ability to integrate with total station survey techniques to accurately record and control excavations and provide a means of visualising stratigraphic, sedimentary, and spatial contexts in various geographical information system platforms. The use of low-cost and time-efficient digital photographic surveys to create accurate 3D models, if completed accurately, can provide researchers with a means of contextualising excavation data without the need for expensive and highly specialised equipment.The development of this method combined with differential global positioning systems provides a solution in more remote locations to recording highly accurate fossil and 3D site contexts with increasing ease. It also allows the sites to be recorded as part of an evolving landscape rather than as single isolated localities. This technique should be a standard technique implemented when working on irreplaceable UNESCO World Heritage sites such as the hominin-bearing caves of South Africa.

Heat treatment of silcretes in the Middle Stone Age of southern Africa has been taken to indicate complex behaviour among early modern humans. This inference is based on the apparent sensitivity of silcretes to rapid changes in temperature, requiring well-regulated heating and cooling rates, and controls over maximum heating temperatures. Alternative arguments have been made that silcrete can effectively be heat treated with limited control over heating rates such that heat treatment may have been a relatively simple process. These apparently contrasting points of view elide the fact that different silcretes may respond differently to heating, and that no single approach may be appropriate in all cases. To test this proposition, we undertook a series of controlled experiments in which silcrete from two sources on the south coast of Australia were prepared into blocks of specific sizes and heated rapidly to a range of maximum temperatures in a muffle furnace. In addition to potential differences in response between sources to heat, our experiments test two factors-stone volume and maximum heating temperature-that were advanced by past explanatory models to account for the probability of sample failure (fracture) during heating. The results of our experiments suggest that the tolerance of silcretes to high heating rates is highly variable between sources within regions, and that the effect of variation between sources is stronger than the other factors examined. Additional tests on limited samples from sources in South Africa support the general relevance of our findings. From these results, we infer that optimal approaches to heating in the past were probably sensitive to the silcretes being heated.