Improved detection of blood stream pathogens by real-time PCR in severe sepsis

Evaluation of the technical and diagnostic feasibility of commercial multiplex real-time polymerase chain reaction (PCR) for detection of blood stream infections in a cohort of intensive care unit (ICU) patients with severe sepsis, performed in addition to conventional blood cultures.

Abandoned Coal Mine Drainage and Its Remediation: Impacts on Stream Ecosystem Structure and Function

The effects of abandoned mine drainage (AMD) on streams and responses to remediation efforts were studied using three streams (AMD-impacted, remediated, reference) in both the anthracite and the bituminous coal mining regions of Pennsylvania (USA). Response variables included ecosystem function as well as water chemistry and macroinvertebrate community composition. The bituminous AMD stream was extremely acidic with high dissolved metals concentrations, a prolific mid-summer growth of the filamentous alga, Mougeotia, and .10-fold more chlorophyll than the reference stream. The anthracite AMD stream had a higher pH, substrata coated with iron hydroxide(s), and negligible chlorophyll. Macroinvertebrate communities in the AMD streams were different from the reference streams, the remediated streams, and each other. Relative to the reference stream, the AMD stream(s) had (1) greater gross primary productivity (GPP) in the bituminous region and undetectable GPP in the anthracite region, (2) greater ecosystem respiration in both regions, (3) greatly reduced ammonium uptake and nitrification in both regions, (4) lower nitrate uptake in the bituminous (but not the anthracite) region, (5) more rapid phosphorus removal from the water column in both regions, (6) activities of phosphorus-acquiring, nitrogenacquiring, and hydrolytic-carbon-acquiring enzymes that indicated extreme phosphorus limitation in both regions, and (7) slower oak and maple leaf decomposition in the bituminous region and slower oak decomposition in the anthracite region. Remediation brought chlorophyll concentrations and GPP nearer to values for respective reference streams, depressed ecosystem respiration, restored ammonium uptake, and partially restored nitrification in the bituminous (but not the anthracite) region, reduced nitrate uptake to an undetectable level, restored phosphorus uptake to near normal rates, and brought enzyme activities more in line with the reference stream in the bituminous (but not the anthracite) region. Denitrification was not detected in any stream. Water chemistry and macroinvertebrate community structure analyses capture the impact of AMD at the local reach scale, but functional measures revealed that AMD has ramifications that can cascade to downstream reaches and perhaps to receiving estuaries.

Use and Performance of In-Stream Structures for River Restoration: a Case Study from North Carolina

In-stream structures including cross-vanes, J-hooks, rock vanes, and W-weirs are widely used in river restoration to limit bank erosion, prevent changes in channel gradient, and improve aquatic habitat. During this investigation, a rapid assessment protocol was combined with post-project monitoring data to assess factors influencing the performance of more than 558 in-stream structures and rootwads in North Carolina. Cross-sectional survey data examined for 221 cross sections from 26 sites showed that channel adjustments were highly variable from site to site, but approximately 60 % of the sites underwent at least a 20 % net change in channel capacity. Evaluation of in-stream structures ranging from 1 to 8 years in age showed that about half of the structures were impaired at 10 of the 26 sites. Major structural damage was often associated with floods of low to moderate frequency and magnitude. Failure mechanisms varied between sites and structure types, but included: (1) erosion of the channel bed and banks (outflanking); (2) movement of rock materials during floods; and (3) burial of the structures in the channel bed. Sites with reconstructed channels that exhibited large changes in channel capacity possessed the highest rates of structural impairment, suggesting that channel adjustments between structures led to their degradation of function. The data question whether currently used in-stream structures are capable of stabilizing reconfigured channels for even short periods when applied to dynamic rivers.

Evaluating Bucknell's Waste Stream

This thesis examines three questions regarding the content of Bucknell University‟s waste stream and the contributors to campus recycling and solid waste disposal. The first asks, “What does Bucknell‟s waste stream consist of?” To answer this question, I designed a campus-wide waste audit procedure that sampled one dumpster from each of the eleven „activity‟ types on campus in order to better understand Bucknell‟s waste composition. The audit was implemented during the Fall semester of the 2011-2012 school year. The waste from each dumpster was sorted into several recyclable and non-recyclable categories and then weighed individually. Results showed the Bison and Carpenter Shop dumpsters to contain the highest percentage of divertible materials (through recycling and/or composting). When extrapolated, results also showed the Dining Services buildings and Facilities buildings to be the most waste dense in terms of pounds of waste generated per square foot. The Bison also generated the most overall waste by weight. The average composition of all dumpsters revealed that organic waste composed 24% of all waste, 23% was non-recyclable paper, and 20% was non-recyclable plastic. It will be important to move forward using these results to help create effective waste programs that target the appropriate areas of concern. My second question asks, “What influences waste behavior to contribute to this „picture‟ of the waste stream?” To answer this question, I created a survey that was sent out to randomly selected sub-group of the university‟s three constituencies: students, faculty, and staff. The survey sought responses regarding each constituency‟s solid waste disposal and recycling behavior, attitudes toward recycling, and motivating factors for solid waste disposal behaviors across different sectors of the university. Using regression analysis, I found three statistically significant motivating factors that influence solid waste disposal behavior: knowledge and awareness, moral value, and social norms. I further examined how a person‟s characteristics associate to these motivating factors and found that one‟s position on campus proved a significant association. Consistently, faculty and staff were strongly influenced by the aforementioned motivating factors, while students‟ behavior was less influenced by them. This suggests that new waste programs should target students to help increase the influence of these motivators to improve the recycling rate and lower overall solid waste disposal on campus. After making overall conclusions regarding the waste audit and survey, I ask my third question, which inquires, “What actions can Bucknell take to increase recycling rates and decrease solid waste generation?” Bucknell currently features several recycling and waste minimization programs on campus. However, using results from the waste audit and campus survey, we can better understand what are the issues of the waste stream, how do we go about addressing these issues, and who needs to be addressed. I propose several suggestions for projects that future students may take on for summer or thesis research. Suggestions include targeting the appropriate categories of waste that occur most frequently in the waste stream, as well as the building types that have the highest waste density and potential recovery rates. Additionally, certain groups on campus should be targeted more directly than others, namely the student body, which demonstrates the lowest influence by motivators of recycling and waste behavior. Several variables were identified as significant motivators of waste and recycling behavior, and could be used as program tactics to encourage more effective behavior.

Monitoring and Modeling of the Hydraulic and Sediment Processes at In-Stream Restoration Structures in the Vicinity of a Bridge Crossing

The long-term performance of infrastructure depends on reliable and sustainable designs. Many of Pennsylvania’s streams experience sediment transport problems that increase maintenance costs and lower structural integrity of bridge crossings. A stream restoration project is one common mitigation measure used to correct such problems at bridge crossings. Specifically, in an attempt to alleviate aggradation problems with the Old Route 15 Bridge crossing on White Deer Creek, in White Deer, PA, two in-stream structures (rock cross vanes) and several bank stabilization features were installed along with a complete channel redevelopment. The objectives of this research were to characterize the hydraulic and sediment transport processes occurring at the White Deer Creek site, and to investigate, through physical and mathematical modeling, the use of instream restoration structures. The goal is to be able to use the results of this study to prevent aggradation or other sediment related problems in the vicinity of bridges through improved design considerations. Monitoring and modeling indicate that the study site on White Deer Creek is currently unstable, experiencing general channel down-cutting, bank erosion, and several local areas of increased aggradation and degradation of the channel bed. An in-stream structure installed upstream of the Old Route 15 Bridge failed by sediment burial caused by the high sediment load that White Deer Creek is transporting as well as the backwater effects caused by the bridge crossing. The in-stream structure installed downstream of the Old Route 15 Bridge is beginning to fail because of the alignment of the structure with the approach direction of flow from upstream of the restoration structure.

The Application of Laser-Ablation Split-Stream ICP Petrochronology to Metamorphic Studies

Discussion of a new, innovative method for dating rocks, called laser ablation split stream (LASS) petrochronology, which is an in situ method that couples geochronological and geochemical data of minerals that remain in the rock matrix. The talk focuses on the application of this technique with U-Th-Pb dating of the phosphate minerals monazite and xenotine in metamorphic rocks. Examples from the Ruby Range in southwestern Montana and metamorphic core complexes in the northern Idaho panhandle will be explored.

Apparatus and Method for Removing Mercury Vapor from a Gas Stream

A metallic filter effectively removes vapor from gas streams. The filter captures the mercury which then can be released and collected as a product. The metallic filter is a copper mesh sponge plated with a six micrometer thickness of gold. The filter removes up to 90% of mercury vapor from a mercury contaminated gas stream.