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United States ports must be prepared for the threat of a small-vessel attack using weapons of mass destruction (WMD). To reduce the risk of such an attack, modeling was conducted at the Savannah River National Laboratory (SRNL) in Aiken, South Carolina, to develop options for redeployment of existing maritime law enforcement resources, deployment of new resources, and optimal use of geographic terrain. Agent-based modeling (ABM) implemented by the Automated Vulnerability Evaluation for Risks of Terrorism (AVERT®) software was used to conduct computer-based simulation modeling. The port-specific models provided estimates for the probability of encountering an adversary based on allocated resources under varying environmental conditions and traffic flow rates. Defensive resources include patrol and response platforms, some of which may be more appropriate in particular environmental conditions. A diverse range of potential adversary and attack scenarios was assessed for a large area port and also for a port with a narrow inlet, thereby identifying vulnerable pathways. For chokepoint operations, the probability of encountering an adversary was estimated for various configurations and operational tempos. As traffic flow increased, the probability of encountering an adversary decreased because the adversary could assimilate into traffic, while security forces were preoccupied inspecting pleasure craft. However, there was a significant increase in the probability of encountering an adversary (P(Encounter)) when additional patrols were added. Noted was a decreasing marginal benefit of additional patrols at low traffic levels. In open water, use of helicopters on patrol substantially increased the P(Encounter) by directing on-water security to target vessels. This capability was due to the far-reaching vision and speed capabilities of helicopters. As a result of ABM, more effective countermeasures can be deployed with available resources to reduce the risk of a small-vessel attack using WMD. The models can be expanded to all ports in the United States using generic models similar to those presented herein that can be matched to any port based on its size and shape. [ABSTRACT FROM PUBLISHER]

It is increasingly common for the electromagnetic borehole flowmeter (EBF) to he used to measure hydraulic conductivity (K) distributions in subsurface flow systems. Past applications involving the EBF have been made mostly in confined aquifers (Kabala 1994; Boman et al. 1997; Podgorney and Ritzi 1997; Ruud and Kabala 1997a, 1997b; Flach et al. 2000), and it has been common to set up a flow field around a test well using a small pump that is located near the top of the well screen (Mob, and Young 1993). In thin, unconfined aquifers that exhibit ground water tables near the ground surface and that undergo drawdown during pumping, such a configuration can be problematical because pumping and associated drawdown may effectively isolate the upper portion of the aquifer from the flowmeter. In these instances, a steady-state flow field in the vicinity of the test well may be created using injection rather than pumping, allowing for testing in the otherwise isolated upper portion of the aquifer located near the initial water table position. Using procedures developed by Molz and Young (1993), which were modified for an injection mode application, testing was conducted to determine whether or not the injection mode would provide useful information in a shallow, unconfined aquifer that required the collection of data near the initial water table position. Results indicated that the injection mode for the EBF was well suited for this objective. [ABSTRACT FROM AUTHOR]

The advent of successful therapy for patients who suffer many types of organ dysfunction and failure, malignancies, and acquired immunodeficiency syndrome has led to the concurrent threat of infection due to a wide array of pathogens, particularly opportunistic microbes that rarely cause disease under routine circumstances. Among patients who are subjected to extreme degrees of immunosuppression, almost any type of bacterial, fungal, viral, protozoal, or parasitic organism can exhibit pathogenic potential and lead to devastating consequences for the host. Immunosuppressive drug therapy for the purpose of organ allograft maintenance, cancer chemotherapy, or the human immunodeficiency virus exerts potent effects upon cellular immunity. Therefore, although these groups of patients are more susceptible to all types of infectious disease processes, infections due to those pathogens that require a component of cellular immunity for their eradication, such as fungi and viruses, occur at a higher frequency than that observed among normal individuals. Of critical importance, all types of infections are associated with higher rates of morbidity and mortality in immunosuppressed patients. Currently, improved diagnostic techniques and new treatment modalities have rendered many serious infections, for which suitable therapy previously did not exist, amenable to treatment. Because of the large number of immunosuppressed patients who now lead highly productive lives, it is important for the surgical practitioner to become familiar with the modalities currently available to precisely diagnose and effectively treat opportunistic infections in immunocompromised surgical patients. [ABSTRACT FROM AUTHOR]

Studies the histopathologic findings, clinical course and therapeutic outcome of patients who developed a lymphoproliferative disorder after undergoing kidney transplantation. Treatment for post-transplant immuno-suppression; Classification of lymphoma according to the International Working Formulation.

Objective: To examine use of third-generation cephalosporins (3GCs) alone and in association with vancomycin hydrochloride as a risk factor for vancomycin-resistant enterococcus (VRE) infection in surgical patients. Design: Case-control retrospective study analyzing antibiotic use in the 30 days preceding culture of VRE or vancomycin-sensitive enterococcus from an infected site. Setting: A large tertiary care teaching hospital. Patients: Surgical inpatients with VRE infections between September 3, 1993, and January 29, 1997, were matched with patients with vancomycin-sensitive enterococcus infections. Matches were based on surgical procedure, initial infection site, and immunosuppression. Matches were found for 32 of 50 surgical patients with VRE. Twenty matched pairs of patients were recipients of solid organ transplants. Main Outcome Measures: Multivariate logistic regression analysis was done to examine 3GCs and vancomycin as risk factors for VRE infection. Univariate analysis of use of other antibiotic agents and demographic data was also performed. Results: Multivariate analysis showed significant differences in the use of 3GCs both alone and concurrently with vancomycin. Univariate analysis also showed higher use of metronidazole, concurrent vancomycin and metronidazole, concurrent vancomycin and ceftazidime, and all antibiotics combined in patients with VRE infections. Conclusions: This matched control study showed that use of 3GCs, alone (P=.05) or concurrently with vancomycin (P=.05), was a risk factor for VRE infection in surgical patients. Judicious administration of third-generation antibiotics is warranted in surgical patients with other risk factors for VRE. [ABSTRACT FROM AUTHOR]