Size corrections based on refractive index for particle measuring systems active scattering aerosol spectrometer probe (ASASP-X)

January 1996.Includes bibliographical references.The response function for the ASASP-X is affected by the optical properties of atmospheric aerosols. The manufacturer calibration is based on polystyrene latex spheres (m=l.588-0i), therefore the size distributions derived from measurements taken with the ASASP-X should be corrected for particles of different refractive index. Corrections based on the manufacturer calibration and Mie theory are used to derive size corrections for different refractive indices. These corrections are applied to data and demonstrate the significant over and underestimation of aerosol volume distributions possible if no corrections to diameter are applied.Funding agency: National Park Service #1443-CA0001-92-006 96.5

Psychological and physiological correlates of sleep in HIV infection

Insomnia, a common problem associated with HIV disease, is most likely caused by a multitude of factors. This study investigated the correlations between a selected group of physiological and psychological factors and sleep quality in an HIV-infected population. A convenience sample of 79 ethnically diverse HIVpositive adults, ages 24 to 63, completed a number of questionnaires and released their laboratory records for CD4+ cell count and viral load information. Variables significantly related to sleep quality were HIV-related symptoms, total pain, fatigue, depression, state anxiety, and the number of adults in the household. Findings support the need for health care providers to consider factors that contribute to impaired sleep when developing effective care for HIV-infected individuals with sleep disturbance

Analytical validation of new ELISAs for the quantitation of polyclonal free light chains and comparison to existing assays for healthy and patient samples

Background: Polyclonal FLCs can be used as a biomarker of inflammation and immune activation in a range of diseases. This study evaluated the performance of new FLC ELISAs (Seralite FLC ELISA) for the quantitation of polyclonal κ and λ FLC, including comparisons to existing assays. Methods: Technical performance was assessed for the ELISA and reference ranges were generated using healthy donor serum (N = 91). Patients with a range of conditions associated with polyclonal FLC dysregulation (N = 164) were measured across platforms. Results: The ELISAs generated references ranges of: 8.72–23.0 mg/L κ FLC, and 8.52–25.24 mg/L for λ FLC. ELISAs demonstrated linearity across the calibration range and intra-assay (≤ 8.7%) and inter-assay (≤ 12.3%) imprecision was low. The limit of detection was 0.63 mg/L for κ and 0.57 mg/L for λ FLC. Minimal cross-reactivity was observed for interference agents, alternate FLC and whole immunoglobulin (median change ≤3.6 mg/L). Assays showed good batch-to-batch consistency. For patient samples, methods generated different κ and λ FLC concentrations and differences were seen between methods for the number of patients classified as below, with and above references ranges for κ and λ FLC. There was no significant difference in the FLC sum between the different techniques. Conclusions: The ELISAs displayed good analytical and technical performance. The quantification of individual κ and λ FLC appears inherently different between platforms. These differences are attenuated if using the FLC sum, which was similar between methods and provided agreement in relation to patients having normal or elevated FLCs.</p

Analytical validation of new ELISAs for the quantitation of polyclonal free light chains and comparison to existing assays for healthy and patient samples

Background: Polyclonal FLCs can be used as a biomarker of inflammation and immune activation in a range of diseases. This study evaluated the performance of new FLC ELISAs (Seralite FLC ELISA) for the quantitation of polyclonal κ and λ FLC, including comparisons to existing assays. Methods: Technical performance was assessed for the ELISA and reference ranges were generated using healthy donor serum (N = 91). Patients with a range of conditions associated with polyclonal FLC dysregulation (N = 164) were measured across platforms. Results: The ELISAs generated references ranges of: 8.72–23.0 mg/L κ FLC, and 8.52–25.24 mg/L for λ FLC. ELISAs demonstrated linearity across the calibration range and intra-assay (≤ 8.7%) and inter-assay (≤ 12.3%) imprecision was low. The limit of detection was 0.63 mg/L for κ and 0.57 mg/L for λ FLC. Minimal cross-reactivity was observed for interference agents, alternate FLC and whole immunoglobulin (median change ≤3.6 mg/L). Assays showed good batch-to-batch consistency. For patient samples, methods generated different κ and λ FLC concentrations and differences were seen between methods for the number of patients classified as below, with and above references ranges for κ and λ FLC. There was no significant difference in the FLC sum between the different techniques. Conclusions: The ELISAs displayed good analytical and technical performance. The quantification of individual κ and λ FLC appears inherently different between platforms. These differences are attenuated if using the FLC sum, which was similar between methods and provided agreement in relation to patients having normal or elevated FLCs.</p

Trehalose Uptake through P2X7 Purinergic Channels Provides Dehydration Protection

The tetra-anionic form of ATP (ATP4-) is known to induce monovalent and divalent ion fluxes in cells that express purinergic P2X7 receptors (Steinberg et al., 1987; Sung et al., 1985), and with sustained application of ATP it has been shown that dyes as large as 831 daltons can permeate the cell membrane (Steinberg et al, 1987). The current study explores the kinetics of loading α,α-trehalose (342 daltons) into ATP stimulated J774.A1 cells, which are known to express the purinergic P2X7 receptor (Steinberg et al., 1987). Cells that were incubated at 37 ̊C in a 50 mM phosphate buffer (pH 7.0) contailing 225 mM trehalose and 5 mM ATP, were shown to load trehalose linearly over time. Concentrations of ~50 mM were reached within 90 min of incubation. Cells incubated in the same solution at 4 ̊C loaded minimally, consistent with the inactivity of the receptor at low temperatures. However, extended incubation at 37 oC (\u3e60 min) resulted in zero next-day survival, with adverse effects appearing even with incubation periods as short as 30 min. By using a two-step protocol with a short time period at 37 oC to allow pore formation, followed by an extended loading period on ice, cells could be loaded with up to 50 mM trehalose while maintaining good next day recovery (49% ± 12 % by Trypan Blue exclusion, 56 ± 20% by Alamar BlueTM assay). Cells porated by this method and allowed an overnight recovery period exhibited improved dehydration tolerance suggesting a role for ATP poration in the anhydrous preservation of cells

Experiences of learning through collaborative evaluation from a masters programme in professional education

This paper presents findings from a collaborative evaluation project within a masters programme in professional education. The project aimed to increase knowledge of research methodologies and methods through authentic learning where participants worked in partnership with the tutor to evaluate the module which they were studying. The project processes, areas of the course evaluated and the data collection methods are outlined. The findings focus on key themes from evaluating the effectiveness of using a collaborative evaluation approach, including: enhanced student engagement; creativity of the collaborative evaluation approach; equality between the tutor and students; and enhanced research skills. Discussion focuses on the outcomes and effectiveness of the project and tutor reflections on adopting a collaborative approach. This paper highlights lessons from the project relevant to those interested in staff-student partnership approaches and those facilitating postgraduate learning and teaching programmes and educational research courses

Renewable Energy Opportunities at Fort Polk, Louisiana

This document provides an overview of renewable resource potential at Fort Polk, based primarily upon analysis of secondary data sources supplemented with limited on-site evaluations. This effort focuses on grid-connected generation of electricity from renewable energy sources and also on ground source heat pumps for heating and cooling buildings. The effort was funded by the U.S. Army Installation Management Command (IMCOM) as follow-on to the 2005 Department of Defense (DoD) Renewables Assessment. The site visit to Fort Polk took place on February 16, 2010

Renewable Energy Assessment Methodology for Japanese OCONUS Army Installations

Since 2005, Pacific Northwest National Laboratory (PNNL) has been asked by Installation Management Command (IMCOM) to conduct strategic assessments at selected US Army installations of the potential use of renewable energy resources, including solar, wind, geothermal, biomass, waste, and ground source heat pumps (GSHPs). IMCOM has the same economic, security, and legal drivers to develop alternative, renewable energy resources overseas as it has for installations located in the US. The approach for continental US (CONUS) studies has been to use known, US-based renewable resource characterizations and information sources coupled with local, site-specific sources and interviews. However, the extent to which this sort of data might be available for outside the continental US (OCONUS) sites was unknown. An assessment at Camp Zama, Japan was completed as a trial to test the applicability of the CONUS methodology at OCONUS installations. It was found that, with some help from Camp Zama personnel in translating and locating a few Japanese sources, there was relatively little difficulty in finding sources that should provide a solid basis for conducting an assessment of comparable depth to those conducted for US installations. Project implementation will likely be more of a challenge, but the feasibility analysis will be able to use the same basic steps, with some adjusted inputs, as PNNL’s established renewable resource assessment methodology

Development of a rapid and quantitative lateral flow assay for the simultaneous measurement of serum κ and λ immunoglobulin free light chains (FLC):inception of a new near-patient FLC screening tool

Item does not contain fulltextBACKGROUND: Serum free light chains (FLC) are sensitive biomarkers used for the diagnosis and management of plasma cell dyscrasias, such as multiple myeloma (MM), and are central to clinical screening algorithms and therapy response criteria. We have developed a portable, near-patient, lateral-flow test (Seralite(R)) that quantitates serum FLC in 10 min, and is designed to eliminate sample processing delays and accelerate decision-making in the clinic. METHODS: Assay interference, imprecision, lot-to-lot variability, linearity, and the utility of a competitive-inhibition design for the elimination of antigen-excess ('hook effect') were assessed. Reference ranges were calculated from 91 healthy donor sera. Preliminary clinical validation was conducted by retrospective analysis of sera from 329 patients. Quantitative and diagnostic results were compared to Freelite(R). RESULTS: Seralite(R) gave a broad competitive-inhibition calibration curve from below 2.5 mg/L to above 200 mg/L, provided good assay linearity (between 1.6 and 208.7 mg/L for kappa FLC and between 3.5 and 249.7 mg/L for lambda FLC) and sensitivity (1.4 mg/L for kappa FLC and 1.7 mg/L for lambda FLC), and eliminated anomalous results from antigen-excess. Seralite(R) gave good diagnostic concordance with Freelite(R) (Roche Hitachi Cobas C501) identifying an abnormal FLC ratio and FLC difference in 209 patients with newly diagnosed MM and differentiating these patients from normal healthy donors with polyclonal FLC. CONCLUSIONS: Seralite(R) sensitively quantitates FLC and rapidly identifies clinical conditions where FLC are abnormal, including MM