The goal of a fugitive-search game on a graph is to trap a fugitive that hides on the vertices of the graph by systematically placing searchers on the vertices. The fugitive is assumed to have complete knowledge of the graph and of the searchers’ moves, but is restricted to move only along paths whose vertices are not guarded by searchers. The search number of the graph is the least number of s...

Long-term survival of Escherichia coli O157:H7 in soil and in the rhizosphere of many crops after fumigation is relatively unknown. One of the critical concerns with food safety is the transfer of pathogens from contaminated soil to the edible portion of the plants. Multiplex fluorogenic polymerase chain reaction was used in conjunction with plate counts to quantify the survival of E. coli O157...

Introduction: Endodontic treatment failure is caused by the leakage of microorganisms and endotoxins, which leads to pathological lesions. Adequate seal of the root canal is essential to preventing recontamination and ensuring the long-term clinical success rate. Mineral trioxide aggregate (MTA) and calcium-enriched mixture cement (CEM) are common types of cement with adequate ...

Endoscopes are used frequently for the diagnosis and therapy of medical disorders. For example, greater than 10000000 gastrointestinal endoscopic procedures are performed each year in the United States. Failure to employ appropriate cleaning and disinfection/sterilization of endoscopes has been responsible for multiple nosocomial outbreaks and serious, sometimes life-threatening, infections. Fl...

Using two studies of a simple design it has been possible to furnish proof of the influence of hand hygiene prior to insertion of peripheral venous catheters on the incidence of complications. In the first study detailed data were collected anonymously for each patient on the procedure used for catheter insertion or on any complications. Data were collected for around 64% of patients in one hos...

In Australia, rainwater is an important source of water for many households. Unlike municipal water, rainwater is often consumed untreated. This study investigated the potential contamination of rainwater by microorganisms. Samples from 53 rainwater tanks across the Adelaide region were collected and tested using Colilert™ IDEXX Quanti-Tray*/2000. Twenty-eight out of the 53 tanks (53%) containe...

The aim of this study was to evaluate the integrity of the coronal seal of Temp-Bond and compare it to Cavit and IRM after post space preparation using S. faecalis as a microbial tracer. In addition, the affect of two methods of gutta percha removal on the apical seal of root canal fillings was also evaluated. Forty extracted human single rooted teeth were prepared chemomechanically and obturat...

This paper is concerned with the graph searching game. The search number s(G) of a graph G is the smallest number of searchers required to “clear” G. A search strategy is monotone (m) if no recontamination ever occurs. It is connected (c) if the set of clear edges always forms a connected subgraph. It is internal (i) if the removal of searchers is not allowed. The difficulty of the “connected” ...

Persistence of E. coli O157 in the environment is a serious public health concern. However, little is known about the persistence of this pathogen after exposure to chemical compounds like fumigants in the environment. In this study, the persistence behavior of pathogenic E. coli O157:H7 was investigated after fumigation with methyl bromide (MeBr; CH(3)Br) and methyl iodide (MeI, iodomethane; C...

Short-term performance of permeable sand cap test cells, installed over sediment containing liquid coal tar was monitored on the Grand Calumet River (Hammond, Indiana, USA). The sand cap test cells included two sand-only cells, two test cells containing a sand/peat mixed layer, two test cells containing a sand/organoclay mixed layer, and two sediment control cells. In each test cell, six monocy...