MAT-752: FIELD TESTING AND EVALUATION OF RECLAIMED MATERIALS AS AGGREGATE FOR OPSS GRANULAR B TYPE II

In urbanized regions of Ontario, the road construction industry faces a number of challenges due to the growing scarcity of locally-sourced natural aggregate materials and increased restrictions on the approval and development of new aggregate extraction sites. In an effort to maintain sustainable and economical sources of construction aggregates, companies are increasingly seeking to supplement or replace natural aggregates with available artificial materials such as crushed reclaimed concrete aggregate (RCA), and reclaimed asphalt pavement (RAP). Currently, Ontario Provincial Standard Specification (OPSS) 1010 permits the use of processed reclaimed construction materials in a variety of road base, subbase and asphaltic concrete layers, with the exception of Granular B Type II, which is a higher-performance subbase specification that solely allows primary materials produced from crushed bedrock. Consequently, there is a need to better understand the performance of reclaimed materials as alternative aggregates in Granular B Type II. This paper focuses on a field testing program carried out at two job sites in Ontario. This testing program assessed five different aggregate blends conforming to Granular B Type II gradation requirements which vary in composition from 100% natural crushed rock to 100% processed RCA. Test pads were constructed from each blended material to assess field compactibility using a nuclear density gauge and to determine the in-situ moduli of the compacted materials using a portable lightweight deflectometer (LWD). The field testing results indicate that RCA and RAP can be successfully utilized as aggregate materials in Granular B Type II subbase applications

Effect of ambient humidity on the Cochet-Bonnet aesthesiometer

Purpose: The Cochet–Bonnet (COBO) aesthesiometer is the current standard in corneal sensitivity assessment. This study investigates the influence of ambient room humidity levels on the stimulus force exerted by the instrument. Methods: A COBO instrument (Luneau Opthalmologie) with 0.12 mm nominal nylon filament diameter was placed in an environment chamber (Electro-tech systems Inc. PA, USA) at 25 °C and relative humidity (%RH) set to either 20–80%, in 10% steps. After 12 h in the chamber at a chosen %RH level, the instrument was removed and exerted force measured by pressing the nylon filament onto the plate of an analytical microbalance (Mettler-Toledo AB265; precision ±0.0001 g) at a perpendicular angle, by a predetermined amount. Exerted force onto the microbalance was recorded in grams for a specified filament length. Procedure was repeated for filament lengths 10–60 mm, in 5 mm steps. The instrument was returned to the chamber and procedure repeated 5 times, before repeating at the next %RH setting (random order). Measurements at each filament lengths were compared using one-way ANOVA and post-hoc Tukey’s range test. A p-value < 0.05 denoted statistical significance. Results: Significant differences in exerted force were observed with alteration in %RH levels for each filament length (all p < 0.001). Exerted force decreased significantly with an increase in %RH for all filament lengths, with the average force decreasing by 15% with each 10% rise in %RH. Conclusions: This study confirms previous suggestions that the rigidity of the COBO nylon filament is affected by ambient room humidity levels, with implications on the stimulus force delivered by the instrument. A conversion table is provided for converting filament lengths to pressure for a range of relative humidity levels

Childhood membranoproliferative glomerulonephritis type I: Limited steroid therapy

Childhood membranoproliferative glomerulonephritis type I: Limited steroid therapy. Nineteen patients with biopsy proven membranopro liferative glomerulonephritis type I (MPGN I) and a minimum of three years of follow-up (mean 6.5 ± 0.7 years) have been treated with an uncontrolled regimen of limited corticosteroids . Initial therapy ranged from 20 mg per os (po) every other day to 30 mg/kg/day i.v. for three consecutive days, depending on clinical disease severity. Therapy was then decreased based on each patient's improving clinical status. At diagnosis creatinine clearance (Ccr) was < 80 ml/min/l .73 m2 in 12 patients and < 50 in 2. All patients had hematuria and proteinuria, with 15 in the nephrotic range. Hypertension, present at diagnosis in 13, developed in five others following institution of prednisone, and was controlled medically. Renal biopsy was repeated after two years of therapy prior to cessation of treatment (mean total treatment duration 38 ± 3 months). Follow-up biopsy revealed decreased glomerular inflamn activity in 88% of patients. All patients have now been off prednisone for 40 ± 9 months. The mean CCr is 126 ± 5 ml/min/l.73 m2. Eight patients have normal urinalyses. These data suggest that early therapy with a limited course of corticosteroids, and control of associ ated hypertension, may forestall progressive renal insufficiency in children with MPGN type I

Corneal sensitivity after ocular surgery

The cornea is densely innervated with free nerve endings to provide a high level of sensitivity to foreign bodies or noxious substances. They also provide trophic support to the tissues of the cornea and facilitate their repair and replacement. Any reduction in the function of the nerve endings through disease, contact lens wear, or surgery may lead to corneal disease, damage, or reduced healing. Assessment of the corneal nerve function can be made by the use of specialized instruments (aesthesiometers) that stimulate the corneal nerves using different modalities—mechanical, chemical, and thermal. Each modality assesses the function of a different cohort of corneal nerve type. Ocular surgery, particularly corneal surgery, can produce significant damage to the corneal innervation. However, for the majority of surgical procedures, corneal sensation eventually returns to preoperative levels, given enough time. The principal exceptions to this are penetrating keratoplasty, epikeratophakia, and cryo-keratomileusis, where sensation rarely returns to normal. For all types of surgery, the pattern of corneal sensation loss and recovery depends on the type, depth, and extent of incision because these influence the number of nerve fibers severed, and on the healing response of the patient

Balloon-Borne Hard X-Ray Imaging and Future Surveys

Several payloads for hard X-ray (20-600 keV) imaging with coded aperture telescopes have been developed for balloon flight observations of cosmic x-ray sources. We briefly review the characteristics of these, particularly the EXITE2 system. The recent NASA program to develop an extended long duration (100d) balloon flight capability employing super-pressure balloons would allow a qualitatively new hard x-ray imaging experiment: the Energetic X-ray Imaging Survey Telescope-Long Integration Time Experiment (EXIST-LITE). The longer continuous viewing times (per source) available from an LDB platform than from low earth orbit would enable both surveys and objectives complementary to the EXIST mission proposed for a MIDEX satellite. We summarize the scientific objectives of EXIST-LITE, a possible instrumentation approach incorporating a large area array of Cd-Zn-Te (CZT) detectors, and our program for the development and balloon flight testing of relatively thick (5mm) CZT detector arrays.Comment: 10 pages Latex and includes 3 figures (postscript). Invited talk at COSPAR (Birmingham, UK; July 96); to appear in Adv. in Sp. Res. (1998

Development of an XSPEC-Based Spectral Analysis System for the Coded-Aperture Hard X-ray Balloon Payload EXITE2

We present the spectral analysis system for the second-generation Energetic X-ray Imaging Telescope Experiment (EXITE2) balloon payload. EXITE2 is an imaging hard X-ray telescope using a coded-aperture mask and a NaI/CsI phoswich detector operating in the energy range 20--600 keV. The instrument was flown on a high-altitude scientific balloon from Ft. Sumner, NM on 1997 May 7-8. We describe the details of the EXITE2 spectral analysis system, with emphasis on those aspects peculiar to coded-aperture instruments. In particular, we have made our analysis compatible with the standard X-ray spectral fitting package XSPEC by generating a response matrix in the appropriate format including all the effects of a coded-aperture system. The use of XSPEC, which may be a first for coded-aperture data, permits great flexibility in the fitting of spectral models. The additional effects of our phoswich system, or any other detector-specific considerations, may be easily included as well. We test our spectral analysis using observations of the Crab Nebula, and find that the EXITE2 Crab spectrum is consistent with those recorded by previous instruments operating in this energy range.Comment: 17 pages LaTeX, 6 figures, accepted to Astroparticle Physic

Interaction of Disulfiram with Antiretroviral Medications: Efavirenz Increases While Atazanavir Decreases Disulfiram Effect on Enzymes of Alcohol Metabolism

Background and Objectives Alcohol abuse complicates treatment of HIV disease and is linked to poor outcomes. Alcohol pharmacotherapies, including disulfiram (DIS), are infrequently utilized in co-occurring HIV and alcohol use disorders possibly related to concerns about drug interactions between antiretroviral (ARV) medications and DIS. Method This pharmacokinetics study (n = 40) examined the effect of DIS on efavirenz (EFV), ritonavir (RTV), or atazanavir (ATV) and the effect of these ARV medications on DIS metabolism and aldehyde dehydrogenase (ALDH) activity which mediates the DIS-alcohol reaction. Results EFV administration was associated with decreased S-Methyl-N-N-diethylthiocarbamate (DIS carbamate), a metabolite of DIS (p = .001) and a precursor to the metabolite responsible for ALDH inhibition, S-methyl-N,N-diethylthiolcarbamate sulfoxide (DETC–MeSO). EFV was associated with increased DIS inhibition of ALDH activity relative to DIS alone administration possibly as a result of EFV-associated induction of CYP 3A4 which metabolizes the carbamate to DETC–MeSO (which inhibits ALDH). Conversely, ATV co-administration reduced the effect of DIS on ALDH activity possibly as a result of ATV inhibition of CYP 3A4. DIS administration had no significant effect on any ARV studied. Discussion/Conclusions ATV may render DIS ineffective in treatment of alcoholism. Future Directions DIS is infrequently utilized in HIV-infected individuals due to concerns about adverse interactions and side effects. Findings from this study indicate that, with ongoing clinical monitoring, DIS should be reconsidered given its potential efficacy for alcohol and potentially, cocaine use disorders, that may occur in this population. (Am J Addict 2014;23:137–144

Glucose-induced down regulation of thiamine transporters in the kidney proximal tubular epithelium produces thiamine insufficiency in diabetes

Increased renal clearance of thiamine (vitamin B1) occurs in experimental and clinical diabetes producing thiamine insufficiency mediated by impaired tubular re-uptake and linked to the development of diabetic nephropathy. We studied the mechanism of impaired renal re-uptake of thiamine in diabetes. Expression of thiamine transporter proteins THTR-1 and THTR-2 in normal human kidney sections examined by immunohistochemistry showed intense polarised staining of the apical, luminal membranes in proximal tubules for THTR-1 and THTR-2 of the cortex and uniform, diffuse staining throughout cells of the collecting duct for THTR-1 and THTR-2 of the medulla. Human primary proximal tubule epithelial cells were incubated with low and high glucose concentration, 5 and 26 mmol/l, respectively. In high glucose concentration there was decreased expression of THTR-1 and THTR-2 (transporter mRNA: −76% and −53% respectively, p<0.001; transporter protein −77% and −83% respectively, p<0.05), concomitant with decreased expression of transcription factor specificity protein-1. High glucose concentration also produced a 37% decrease in apical to basolateral transport of thiamine transport across cell monolayers. Intensification of glycemic control corrected increased fractional excretion of thiamine in experimental diabetes. We conclude that glucose-induced decreased expression of thiamine transporters in the tubular epithelium may mediate renal mishandling of thiamine in diabetes. This is a novel mechanism of thiamine insufficiency linked to diabetic nephropathy