A Report to the Parents of Detroit on Decentralization

https://digitalcommons.usm.maine.edu/detroitgeographicalexpedition/1000/thumbnail.jp

Microbiological Evaluation of Water Quality from Urban Watersheds for Domestic Water Supply Improvement

Agricultural and urban runoffs may be major sources of pollution of water bodies and major sources of bacteria affecting the quality of drinking water. Of the different pathways by which bacterial pathogens can enter drinking water, this one has received little attention to date; that is, because soils are often considered to be near perfect filters for the transport of bacterial pathogens through the subsoil to groundwater. The goals of this study were to determine the distribution, diversity, and antimicrobial resistance of pathogenic Escherichia coli isolates from low flowing river water and sediment with inputs from different sources before water is discharged into ground water and to compare microbial contamination in water and sediment at different sampling sites. Water and sediment samples were collected from 19 locations throughout the watershed for the isolation of pathogenic E. coli. Heterotrophic plate counts and E. coli were also determined after running tertiary treated water through two tanks containing aquifer sand material. Presumptive pathogenic E. coli isolates were obtained and characterized for virulent factors and antimicrobial resistance. None of the isolates was confirmed as Shiga toxin E. coli (STEC), but as others, such as enterotoxigenic E. coli (ETEC). Pulsed field gel electrophoresis (PFGE) was used to show the diversity E. coli populations from different sources throughout the watershed. Seventy six percent of the isolates from urban sources exhibited resistance to more than one antimicrobial agent. A subsequent filtration experiment after water has gone through filtration tanks containing aquifer sand material showed that there was a 1 to 2 log reduction in E. coli in aquifer sand tank. Our data showed multiple strains of E. coli without virulence attributes, but with high distribution of resistant phenotypes. Therefore, the occurrence of E. coli with multiple resistances in the environment is a matter of great concern due to possible transfer of resistant genes from nonpathogenic to pathogenic strains that may result in increased duration and severity of morbidity

Closed-form analytical expressions for the potential fields generated by triangular monolayers with linearly distributed source strength

The solution of the mixed boundary value problem of potential theory involves the computation of the potential field generated by monolayer and double layer source distributions on surfaces at which boundary conditions are known. Closed-form analytical expressions have been described in the literature for the potential field generated by double layers having a linearly distributed strength over triangular source elements. This contribution presents the corresponding expression for the linearly distributed monolayer strength. The solution is shown to be valid for all observation points in space, including those on the interior, edges and vertices of the source triangle

Abstract Call with Current Continuation Patterns

This paper outlines the recurring use of continuations. A brief overview of continuations is given. This is followed by several patterns that outline the use of continuations leading up to using continuations to implement coroutines, explicit backtracking, and multitasking. Scheme is used for the examples as it supports first class continuations.

The Efficiency of Biofilters at Mitigating Airborne MRSA from a Swine Nursery

Our prior studies have been in agreement with other researchers in detecting airborne methicillin-resistant (MRSA) inside and downwind of a swine housing facility. MRSA emitted in the exhaust air of swine facilities creates a potential risk of transmission of these organisms to people in the general area of these facilities as well as to other animals. This study investigated a possible means of reducing those risks. We investigated the efficiency of biofilters to remove MRSA from the exhaust air of a swine building. Two types of biofilter media (hardwood chips and western red cedar shredded bark) were evaluated. Efficiency was measured by assessing both viable MRSA (viable cascade impactor) and dust particles (optical particle courter) in the pre-filtered and post-filtered air of a functioning swine production facility. Our study revealed that hardwood chips were respectively 92% and 88% efficient in removing viable MRSA and total dust particles. Western red cedar was 95% efficient in removing viable MRSA and 86% efficient in removing dust particles. Our findings suggest that biofilters can be used as effective engineering controls to mitigate the transmission of aerosolized MRSA in the exhaust air of enclosed swine housing facilities.This article was published in Journal of Agricultural Safety and Health 21(4): 217-227 (doi: 10.13031/jash.21.10716). 2015 American Society of Agricultural and Biological Engineers.</p

Trospectomycin Enhances Surface Phagocytosis of Bacteroides and Staphylococcus by Altering the Bacterial Glycocalyx

The influence of trospectomycin on phagocytosis of Bacteroides thetaiotaomicron, Bacteroides fragilis and Staphylococcus epidermidis was studied in the presence or absence of glycocalyx isolated from these microorganisms. Bacteria were grown with or without 0.25 or 0.5 of the minimal inhibitory concentration (MIC) of trospectomycin, a new chemically synthesized analog of spectinomycin. Surface phagocytosis by human polymorphonuclear leukocytes (PMNL) was determined using a modified fluorochrome assay. Subinhibitory concentrations of trospectomycin significantly enhanced surface phagocytosis of Bacteroides and Staphylococcus. When homologous or heterologous isolated glycocalyx was added to trospectomycin treated bacteria prior to incubation with PMNL, phagocytosis was reduced to levels observed in the untreated bacteria. Addition of glycocalyx to untreated strains produced no significant reduction of phagocytosis. The glycocalyx preparations were free of lipopolysaccharide and did not affect PMNL viability

Campylobacter Fetus Ssp Jejuni: Isolation From Patients With Gastroenteritis

Within a seven-month period, Campylobacter fetus ssp jejuni was isolated in East Tennessee from 18 patients with gastroenteritis; 83% of these patients had bloody diarrhea. Absence of other enteric organisms such as Salmonella, Shigella, and Yersinia implicated C fetus ssp jejuni as the causative agent. A fourfold increase in titer by tube agglutination from four of eight patients studied supported the pathogenicity of this organism. Treatment with erythromycin alleviated gastroenteritis symptoms within 24 to 48 hours, with concurrent disappearance of the organism from the feces. An isolation rate of 8% in our patients indicates that C fetus ssp jejuni is more common as a cause of human diarrhea than Salmonella or Shigella. The severity of the C fetus ssp jejuni gastroenteritis poses a possible reclassification from diarrhea or gastroenteritis to acute dysentery syndrome

Molecular Docking and 3-D QSAR Studies of Substituted 2,2-Bisaryl-Bicycloheptanes as Human 5-Lipoxygenase-Activating Protein (FLAP) Inhibitors

Leukotrienes have been shown to be involved in a variety of diseases such as cardiovascular diseases, cancer, asthma, ulcerative colitis, and rhinitis. 5-Lipoxygenase-Activating Protein (FLAP) was found to be a key enzyme of leukotriene synthesis. Comparative Molecular Field Analysis (CoMFA) and molecular docking studies were carried out on a series of substituted 2,2-bisaryl-bicycloheptanes FLAP inhibitors. The docking results provided a reliable conformational alignment scheme for 3-D QSAR model. Based on the docking conformations, highly predictive CoMFA model was performed with a leave-one-out cross-validated q2 of 0.651. The noncross-validated analysis with four optimum components revealed a conventional r2 value of 0.972, F=175.674, and an estimated standard error of 0.169. The predictive ability of this model was validated by the testing set with a conventional r2 value of 0.920. The analyses may be used to design more potent FLAP inhibitors and predict their activities prior to synthesis