Use of the C18 (Octadecyl) Solid Phase Extraction Column for Wastewater Toxicity Identification and Characterization

Biomonitoring requirements are continually being added to NPDES permits. As a result, many municipal wastewater treatment facilities have been identified as having effluent acute toxicity. To solve this problem, the Environmental Protection Agency (EPA) has developed a Toxicity Identification Evaluation (TIE) protocol. This protocol lists a set of simple procedures which are used to separate whole effluent samples into different fractions containing different classes of similar compounds. Toxic fractions are further separated and concentrated using various techniques to assist in the possible identification of certain classes of suspected toxic compounds. Once sample fractionation and toxicity testing have been thoroughly investigated, chemical-specific analyses are conducted to tentatively identify toxic constituents. The C18 (Octadecyl) Solid Phase Extraction (SPE) Column is used in the TIE protocol to separate and concentrate moderately polar to nonpolar organic compounds from toxic effluent samples. An increasing gradient of methanol (MeOH) in water is used to elute the column; the objective is to separate retained compounds into eight different fractions based on their polarity. The objective of conducting this research is to determine if the C18 SPE Column elution procedure is a viable technique for the identification and characterization of toxic effluents. This study showed that the C18 column was able to remove compounds causing acute toxicity from samples collected at the Cross Creek Wastewater Treatment Plant (WWTP) in Fayetteville, NC. The 80 to 85 percent MeOH/H20 fractions contained the most toxicity. However, laboratory tests of the procedure using known target compounds indicated that several different MeOH/H20 fractions contained each individual compound thus showing deficiencies in resolution. Moreover, the target compounds that were selected differed widely in polarity (as indicated by the compounds octanol/water partitioning coefficient), yet this did not cause a wide separation of these compounds into specific MeOH/H2O fractions. This research showed the C18 SPE column is capable of retaining relatively non-polar compounds as indicated by the target compound evaluation. These compounds were effectively eluted from the CIS SPE column with MeOH/H20, but separation was not well defined. In the situation of toxic wastewaters, where numerous nonpolar organic compounds may possibly be present in WWTP's discharge, the C18 SPE column provides little information regarding the identity of the non-polar organics causing toxicity in a toxic MeOH/H20 fraction.Master of Science in Environmental Engineerin

Blood and marrow transplantation compensation: Perspective in payer and provider relations

AbstractThe high cost per patient of hematopoietic cell transplantation (HCT) causes this therapy to be the focus of much controversy, given the competing societal demands to provide all possible therapy to preserve life while simultaneously limiting global health care expenditures. Treatment and eligibility decisions for HCT often are heavily scrutinized by both governmental and private payers and not simply determined by physicians, facility providers, and the patient. In an effort to control costs, payers have administrative infrastructure to review resource utilization by these patients. Additionally payers have developed payment methodologies, usually in the form of a case rate payment structure, that place facilities and physician providers of HCT at financial risk for adverse patient financial outcomes in an effort to promote optimal utilization and selection of patients for HCT. As providers enter into such financial risk arrangements with payers, the providers need to understand the true cost of care and be able to identify predictable and unpredictable outlier risks for the financial consequences of medical complications. HCT providers try to protect themselves from excessive financial risk by having different payment rates for different types of transplant, eg, autologous versus HLA or genotypically matched related versus HLA mismatched transplants. Because at certain times in the HCT process risk is more unpredictable, HCT providers require different payment system strategies for the different time periods of care such as evaluation, pre-transplant disease management, harvesting, and cell processing, as well as short- and long-term follow-up. Involvement by clinicians is essential for this process to be done well, especially given the rapid changes technological innovation brings to HCT. Constant dialogue and interaction between providers and payers on these difficult financial issues with HCT is essential to preserve patient access to this potentially lifesaving therapy

Modeling of bone conduction of sound in the human head using hp-finite elements: Code design and verification

We focus on the development of a reliable numerical model for investigating the bone-conduction of sound in the human head. The main challenge of the problem is the lack of fundamental knowledge regarding the transmission of acoustic energy through non-airborne pathways to the cochlea. A fully coupled model based on the acoustic/elastic interaction problem with a detailed resolution of the cochlea region and its interface with the skull and the air pathways, should provide an insight into this fundamental, long standing research problem. To this aim we have developed a 3D hp-finite element code that supports elements of all shapes (tetrahedra, prisms and pyramids) to better capture the geometrical features of the head. We have tested the code on a multilayered sphere and employed it to solve an idealized model of head. In the future we hope to attack a model with a more realistic geometry

Avian response to microclimate in canopy gaps in a bottomland hardwood forest.

Abstract - Microclimate may infl uence use of early successional habitat by birds. We assessed the relationships between avian habitat use and microclimate (temperature, light intensity, and relative humidity) in experimentally created canopy gaps in a bottomland hardwood forest on the Savannah River Site, SC. Gaps were 2- to 3-year-old group-selection timber harvest openings of three sizes (0.13, 0.26, 0.50 ha). Our study was conducted from spring through fall, encompassing four bird-use periods (spring migration, breeding, post-breeding, and fall migration), in 2002 and 2003. We used mist netting and simultaneously recorded microclimate variables to determine the influence of microclimate on bird habitat use. Microclimate was strongly affected by net location within canopy gaps in both years. Temperature generally was higher on the west side of gaps, light intensity was greater in gap centers, and relative humidity was higher on the east side of gaps. However, we found few relationships between bird captures and the microclimate variables. Bird captures were inversely correlated with temperature during the breeding and postbreeding periods in 2002 and positively correlated with temperature during spring 2003. Captures were high where humidity was high during post-breeding 2002, and captures were low where humidity was high during spring 2003. We conclude that variations in the local microclimate had minor infl uence on avian habitat use within gaps. Instead, habitat selection in relatively mild regions like the southeastern US is based primarily on vegetation structure, while other factors, including microclimate, are less important

Mixed T Lymphocyte Chimerism after Allogeneic Hematopoietic Transplantation Is Predictive for Relapse of Acute Myeloid Leukemia and Myelodysplastic Syndromes.

Chimerism testing after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) represents a promising tool for predicting disease relapse, although its precise role in this setting remains unclear. We investigated the predictive value of T lymphocyte chimerism analysis at 90 to 120 days after allo-HSCT in 378 patients with AML/MDS who underwent busulfan/fludarabine-based myeloablative preparative regimens. Of 265 (70%) patients with available T lymphocyte chimerism data, 43% of patients in first or second complete remission (CR1/CR2) at the time of transplantation had complete (100%) donor T lymphocytes at day +90 to +120 compared with 60% of patients in the non-CR1/CR2 cohort (P = .005). In CR1/CR2 patients, donor T lymphocyte chimerism ≤ 85% at day +90 to +120 was associated with a higher frequency of 3-year disease progression (29%; 95% confidence interval [CI], 18% to 46% versus 15%; 95% CI, 9% to 23%; hazard ratio [HR], 2.1; P = .04). However, in the more advanced, non-CR1/CR2 cohort, mixed T lymphocyte chimerism was not associated with relapse (37%; 95% CI, 20% to 66% versus 34%; 95% CI, 25% to 47%; HR, 1.3; P = .60). These findings demonstrate that early T lymphocyte chimerism testing at day +90 to +120 is a useful approach for predicting AML/MDS disease recurrence in patients in CR1/CR2 at the time of transplantation

Mouse Estrous Cycle Identification Tool and Images

The efficiency of producing timed pregnant or pseudopregnant mice can be increased by identifying those in proestrus or estrus. Visual observation of the vagina is the quickest method, requires no special equipment, and is best used when only proestrus or estrus stages need to be identified. Strain to strain differences, especially in coat color can make it difficult to determine the stage of the estrous cycle accurately by visual observation. Presented here are a series of images of the vaginal opening at each stage of the estrous cycle for 3 mouse strains of different coat colors: black (C57BL/6J), agouti (CByB6F1/J) and albino (BALB/cByJ). When all 4 stages (proestrus, estrus, metestrus, and diestrus) need to be identified, vaginal cytology is regarded as the most accurate method. An identification tool is presented to aid the user in determining the stage of estrous when using vaginal cytology. These images and descriptions are an excellent resource for learning how to determine the stage of the estrous cycle by visual observation or vaginal cytology

Allogeneic Hematopoietic Stem Cell Transplant (HSCT) for Patients in the 6th and 7th Decades of Life with AML or MDS Using Myeloablative, Reduced Toxicity IV Busulfan/Fludarabine (BuFlu) Conditioning Regimen

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