Beyond Bacteria: A Study of the Enteric Microbial Consortium in Extremely Low Birth Weight Infants

Extremely low birth weight (ELBW) infants have high morbidity and mortality, frequently due to invasive infections from bacteria, fungi, and viruses. The microbial communities present in the gastrointestinal tracts of preterm infants may serve as a reservoir for invasive organisms and remain poorly characterized. We used deep pyrosequencing to examine the gut-associated microbiome of 11 ELBW infants in the first postnatal month, with a first time determination of the eukaryote microbiota such as fungi and nematodes, including bacteria and viruses that have not been previously described. Among the fungi observed, Candida sp. and Clavispora sp. dominated the sequences, but a range of environmental molds were also observed. Surprisingly, seventy-one percent of the infant fecal samples tested contained ribosomal sequences corresponding to the parasitic organism Trichinella. Ribosomal DNA sequences for the roundworm symbiont Xenorhabdus accompanied these sequences in the infant with the greatest proportion of Trichinella sequences. When examining ribosomal DNA sequences in aggregate, Enterobacteriales, Pseudomonas, Staphylococcus, and Enterococcus were the most abundant bacterial taxa in a low diversity bacterial community (mean Shannon-Weaver Index of 1.02±0.69), with relatively little change within individual infants through time. To supplement the ribosomal sequence data, shotgun sequencing was performed on DNA from multiple displacement amplification (MDA) of total fecal genomic DNA from two infants. In addition to the organisms mentioned previously, the metagenome also revealed sequences for gram positive and gram negative bacteriophages, as well as human adenovirus C. Together, these data reveal surprising eukaryotic and viral microbial diversity in ELBW enteric microbiota dominated bytypes of bacteria known to cause invasive disease in these infants

Two implementations of shared virtual space environments.

While many issues in the area of virtual reality (VR) research have been addressed in recent years, the constant leaps forward in technology continue to push the field forward. VR research no longer is focused only on computer graphics, but instead has become even more interdisciplinary, combining the fields of networking, distributed computing, and even artificial intelligence. In this article we discuss some of the issues associated with distributed, collaborative virtual reality, as well as lessons learned during the development of two distributed virtual reality applications

Performance model of the Argonne Voyager multimedia server

The Argonne Voyager Multimedia Server is being developed in the Futures Lab of the Mathematics and Computer Science Division at Argonne National Laboratory. As a network-based service for recording and playing multimedia streams, it is important that the Voyager system be capable of sustaining certain minimal levels of performance in order for it to be a viable system. In this article, the authors examine the performance characteristics of the server. As they examine the architecture of the system, they try to determine where bottlenecks lie, show actual vs potential performance, and recommend areas for improvement through custom architectures and system tuning

An interactive virtual environment for finite element analysis

Virtual environments (VE) provide a powerful human-computer interface that opens the door to exciting new methods of interaction with high-performance computing applications in several areas of research. The authors are interested in the use of virtual environments as a user interface to real-time simulations used in rapid prototyping procedures. Consequently, the authors are developing methods for coupling finite element models of complex mechanical systems with a VE interface for real-time interaction

CAVEComm

Virtual reality has become an increasingly familiar part of the science of visualization and communication of information. This, combined with the increase in connectivity of remote sites via high-speed networks, allows for the development of a collaborative distributed virtual environment. Such an environment enables the development of supercomputer simulations with virtual reality visualizations that can be displayed at multiple sites, with each site interacting, viewing, and communicating about the results being discovered. The CAVEComm library is a set of routines designed to generalize the communications between virtual environments and supercomputers