bluuebunny/crossref_metadata_2025 huggingface dataset:
Distribution profiles of endocrine disrupting PAHs/APEOs in river sediments: is there a potential ecotoxicological problem?
Authors: Zoller Uri
Published: February 2008

The endocrinic/mutagenic potencies of the endocrine disrupting chemicals (EDCs) polycyclic aromatic hydrocarbons (PAHs), alkylphyenol ethoxylates (APEOs) and their metabolites are well documented. Less so is the endocrinic ecotoxicological/health risk potential of these persistent organic pollutants (POPs) in river sediments. From ∼5 × 108 m3/y of sewage produced in Israel, ∼70% are reused, mainly in agriculture, following a conventional activated sludge treatment (AST). A major related question is: does this practice conform to sustainability? We have found the APEOs concentration profiles of Israel's rivers/streams, Mediterranean Sea coastal water and groundwater, to be 12.5–74.6, 4.5–25.0 and trace−20.2 μg/L, respectively. In two “representative” rivers, in the central coastal region of the country, the total concentrations of the PAHs and APEOs were found to be (in the upper layers of their sediments) 1.02–1.59, 1.78–2.30, 1.48–3.12 and 31.27–376.23, 2.40–91.70, 62.99–63.63 μg/g, respectively. The distribution of the PAHs in the co-presence of APEOs in rivers and their sediments, can be rationalized in terms of the hydrophobicity/nonbiodegradability of the former and the hydrophilicity-CMC/nonbiodegradability of the latter. Based on (a) the zebrafish egg production test (ZFEPT) – a long-term exposure of zebrafish to actually found environmental concentrations of EDCs; and (b) the low effectiveness of POPs removal in AST, our preliminary conclusions are that (1) there is a potential ecotoxicological/health risk problem; and (2) the practice of conventional wastewater treatment plants (WWTPs)-treated water reuse is incompatible with sustainability.
Highly Active Antiretroviral Therapy Does Not Affect Mitochondrial β-Oxidation of Fatty Acids: An in Vitro Study in Fibroblasts
Authors: Butt Yasmeen M. , Kamrudin Samira A. , Rakheja Dinesh
Published: February 2008

Preeclampsia is a multifactorial pregnancy-specific disease. In some cases, severe preeclampsia and related disorders of acute fatty liver of pregnancy and hemolysis, elevated liver enzymes, low platelets syndrome are associated with inherited defects in mitochondrial β-oxidation of fatty acids, especially a deficiency of long-chain 3-hydroxyacyl coenzyme A dehydrogenase (LCHAD). Recently, an unexplained increase in the incidence of preeclampsia has been documented in human immunodeficiency virus (HIV)–infected pregnant women on treatment with highly active antiretroviral therapy (HAART). We performed this study to determine if antiretroviral drugs affect mitochondrial β-oxidation fatty acids in vitro. Two normal and 1 heterozygous LCHAD-deficient cell lines were exposed to up to 5 times the therapeutic concentrations of the following antiretroviral drugs: nevirapine, didanosine, lamivudine, and a combination of nelfinavir, zidovudine, and lamivudine. One homozygous LCHAD-deficient cell line served as the positive control. After exposure of the fibroblasts to these drugs for periods ranging from 2 to 10 days, accumulations of even-chain 3-hydroxy fatty acids (3-OH-C6 to 3-OH-C18) in the culture media were measured by stable-isotope dilution gas chromatography/mass spectrometry. Compared to the respective unexposed fibroblasts, there was no significant build-up of 3-hydroxy fatty acids in the culture media of normal or heterozygous LCHAD-deficient fibroblasts exposed to antiretroviral drugs. Our results show that the commonly used antiretroviral drugs do not adversely affect fatty acid oxidation in fibroblasts. Therefore, an altered fatty acid oxidation may not be the mechanism for the reported increased risk of preeclampsia in HIV-infected pregnant women on HAART.
Effects of carprofen on the integrity and barrier function of canine colonic mucosa
Authors: Briere Catherine A. , Hosgood Giselle , Morgan Timothy W. , Hedlund Cheryl S. , Hicks Merrin , McConnico Rebecca S.
Published: February 2008

Objective—To measure effects of carprofen on conductance and permeability to mannitol and histologic appearance in canine colonic mucosa.

Sample Population—Colonic mucosa from 13 mature mixed-breed dogs.

Procedures—Sections of mucosa from the transverse colon and proximal and distal portions of the descending colon were obtained immediately after dogs were euthanized. Sections were mounted in Ussing chambers. Carprofen (400 μg/mL) was added to the bathing solution for treated sections. Conductance was calculated at 15-minute intervals for 240 minutes. Flux of mannitol was calculated for three 1-hour periods. Histologic examination of sections was performed after experiments concluded. Conductance was graphed against time for each chamber, and area under each curve was calculated. Conductance × time, flux of mannitol, and frequency distribution of histologic findings were analyzed for an effect of region and carprofen.

Results—Carprofen significantly increased mean conductance × time, compared with values for control (untreated) sections for all regions of colon. Carprofen significantly increased mean flux of mannitol from period 1 to period 2 and from period 2 to period 3 for all regions of colon. Carprofen caused a significant proportion of sections to have severe sloughing of cells and erosions involving ≥ 10% of the epithelium, compared with control sections.

Conclusions and Clinical Relevance—Carprofen increased in vitro conductance and permeability to mannitol in canine colonic mucosa. Carprofen resulted in sloughing of cells and erosion of the colonic mucosa. These findings suggested that carprofen can compromise the integrity and barrier function of the colonic mucosa of dogs.
Minimum anesthetic concentration of isoflurane in captive thick-billed parrots (Rhynchopsitta pachyrhyncha)
Authors: Mercado Julio A. , Larsen R. Scott , Wack Raymund F. , Pypendop Bruno H.
Published: February 2008

Objective—To determine the minimum anesthetic concentration (MAC) of isoflurane in thick-billed parrots (Rhynchopsitta pachyrhyncha).

Animals—15 healthy thick-billed parrots.

Procedures—Anesthesia was induced and maintained with isoflurane in oxygen. In the first bird that was anesthetized, end-tidal isoflurane concentration was maintained at 1.0% for 15 minutes. After this period of anesthetic equilibration, an end-tidal gas sample was obtained for verification of isoflurane concentration. A toe was pinched to determine the bird's response to pain, and the bird was then allowed to recover from aesthesia. To determine MAC, a so-called up-and-down approach was subsequently used in all 15 birds. Compared with the isoflurane concentration used for MAC determination in the first bird, maintenance isoflurane concentration for the second bird was increased by approximately 10% if the first bird reacted and decreased by approximately 10% if the first bird did not react to a toe pinch. These steps were then followed until all 15 birds had been anesthetized. Crossover events occurred when birds in sequence had discordant results (ie, 1 reactor and 1 nonreactor). The MAC was defined as the mean of the isoflurane concentrations measured during these crossover events.

Results—Mean MAC of isoflurane in thick-billed parrots was estimated to be 1.07% (95% confidence interval, 0.97% to 1.16%).

Conclusions and Clinical Relevance—Isoflurane MAC appears to be lower in thick-billed parrots than the MAC determined for other bird species. Determination of the species-specific requirements of thick-billed parrots should allow isoflurane anesthesia to be performed more safely in this endangered species.
Inheritance of cataracts and primary lens luxation in Jack Russell Terriers
Authors: Oberbauer Anita M. , Hollingsworth Steven R. , Belanger Janelle M. , Regan Kelly R. , Famula Thomas R.
Published: February 2008

Objective—To characterize heritability and mode of inheritance of cataracts and primary lens luxation in Jack Russell Terriers.

Animals—872 Jack Russell Terriers from which buccal epithelial cells were collected and phenotypes for cataracts and lens luxation were determined and an additional 1,898 Jack Russell Terriers without phenotypic information used to complete pedigree relationships and that were included in the analyses.

Procedures—Narrow-sense heritabilities and genetic correlation for cataracts and lens luxation were modeled by use of threshold analysis, whereas complex segregation analysis was used to characterize mode of inheritance. For the analyses, dogs < 6 years old, unless confirmed as having cataracts or lens luxation, were classified as an unknown phenotype. The possible involvement of an HSF4 mutation in cataracts was determined by DNA sequencing.

Results—Cataracts and primary lens luxation were highly heritable and genetically correlated, and neither was controlled by a single gene. Cataracts were not associated with an HSF4 mutation.

Conclusions and Clinical Relevance—Analysis of the data indicated that concerted selection against both cataracts and primary lens luxation when choosing breeding animals can be used to improve ocular health in Jack Russell Terriers.
Effects of subanesthetic doses of ketamine on hemodynamic and immunologic variables in dogs with experimentally induced endotoxemia
Authors: DeClue Amy E. , Cohn Leah A. , Lechner Elizabeth S. , Bryan Margaret E. , Dodam John R.
Published: February 2008

Objective—To determine the effects of ketamine hydrochloride on hemodynamic and immunologic alterations associated with experimentally induced endotoxemia in dogs.

Animals—9 mixed-breed dogs.

Procedures—In a crossover study, dogs were randomly allocated to receive ketamine (0.5 mg/kg, IV, followed by IV infusion at a rate of 0.12 mg/kg/h for 2.5 hours) or control solution (saline [0.9% NaCl] solution, 0.25 mL, IV, followed by IV infusion at a rate of 0.5 mL/h for 2.5 hours). Onset of infusion was time 0. At 30 minutes, lipopolysaccharide (LPS; 1 μg/kg, IV) was administered. Heart rate (HR), systolic arterial blood pressure (SAP), plasma tumor necrosis factor (TNF)-α activity, and a CBC were evaluated.

Results—Mean SAP was significantly reduced in dogs administered ketamine or saline solution at 2 and 2.5 hours, compared with values at time 0. However, there was no significant difference between treatments. At 1, 2, and 2.5 hours, dogs administered ketamine had a significantly lower HR than dogs administered saline solution. Although plasma TNF-α activity significantly increased, compared with values at time 0 for both groups, ketamine-treated dogs had significantly lower peak plasma TNF-α activity 1.5 hours after LPS administration. All dogs had significant leukopenia and neutropenia after LPS administration, with no differences detected between ketamine and saline solution treatments.

Conclusions and Clinical Relevance—Administration of a subanesthetic dose of ketamine had immunomodulating effects in dogs with experimentally induced endotoxemia (namely, blunting of plasma TNF-α activity). However, it had little effect on hemodynamic stability and no effect on WBC counts.
Use of epidemiologic risk modeling to evaluate control of foot-and-mouth disease in southern Thailand
Authors: Wongsathapornchai Kachen , Salman M. D. , Edwards John R. , Morley Paul S. , Keefe Thomas J. , Campen Hana Van , Weber Steve , Premashthira Sith
Published: February 2008

Objective—To assess the impacts of the introduction of foot-and-mouth disease (FMD) and various FMD control programs in southern Thailand.

Animals—A native population of 562,910 cattle and 33,088 buffalo as well as 89,294 animals legally transported into southern Thailand.

Procedures—A quantitative risk assessment was used to ascertain the probability of FMD introduction, and an intrinsic dynamic model was used to assess impacts. Value for the transmission rate (β) was estimated. Five scenarios created to assess the impacts of nonstructural protein (NSP) testing, mass vaccination, and culling were examined. Impacts were assessed through an examination of the estimated annual cumulative incidence (ACI) of FMD. The ACIs of various scenarios were compared by use of the Tukey Studentized range technique.

Results—β was estimated at 0.115. Approximately 35,000 cases of FMD would be expected from the baseline situation. A 30% reduction of ACI was detected with the introduction of NSP antibody testing. Prophylactic vaccination resulted in an 85% reduction of ACI. Concurrent use of NSP antibody testing and vaccination reduced the ACI by 96%, and the addition of an eradication policy resulted in a slightly greater decrease in the ACI (98%).

Conclusions and Clinical Relevance—The study used epidemiologic models to investigate FMD control interventions. Results suggested that vaccination has more impact than the use of NSP testing. Use of the NSP test reduced ACI during peak seasons, whereas vaccination diminished the underlying incidence. The best mitigation plan was an integrated and strategic use of multiple control techniques.
Assessment of the likelihood of the introduction of foot-and-mouth disease through importation of live animals into the Malaysia-Thailand-Myanmar peninsula
Authors: Wongsathapornchai Kachen , Salman M. D. , Edwards John R. , Morley Paul S. , Keefe Thomas J. , Campen Hana Van , Weber Steve
Published: February 2008

Objective—To assess the likelihood of an introduction of foot-and-mouth disease (FMD) into the Malaysia-Thailand-Myanmar (MTM) peninsula through terrestrial movement of livestock.

Animals—89,294 cattle and buffalo legally moved into the MTM peninsula.

Procedures—A quantitative risk assessment was conducted by use of a stochastic simulation. Patterns of livestock movement were ascertained through review of relevant governmental records and regulations and by interviewing farmers, traders, and local officers when the records did not exist. Parameters identified in the process were the probabilities of livestock having FMD and of FMD infection going undetected during import processes. The probability of an animal accepted for import having FMD was also assessed. Sensitivity analysis was performed to determine the effects that each parameter had on the model.

Results—The simulation yielded an average consignment prevalence of 10.95%. Typically, each animal in a quarantine facility had a 2.7% chance of having an inapparent form of FMD infection; hence, it was likely an animal would not be identified as infected. Findings revealed that the mean probability of an animal accepted for import having FMD was 2.9%, and the risk was as high as 11%.

Conclusions and Clinical Relevance—Results of the model allowed for the evaluation of movement regulations currently imposed in the MTM peninsula. Evidence from the study suggested that current practices in animal movement were far from efficient in preventing introduction of FMD-infected animals into the MTM region, and additional measures will be necessary.
Effects of the topically applied calcium-channel blocker flunarizine on intraocular pressure in clinically normal dogs
Authors: Greller Andrew L. , Hoffman Allison R. , Liu Chengcheng , Ying Gui-shuang , Vudathala Daljit K. , Acland Gregory M. , Komáromy András M.
Published: February 2008

Objective—To determine effects of the topically applied calcium-channel blocker flunarizine on intraocular pressure (IOP) in clinically normal dogs.

Animals—20 dogs.

Procedures—Baseline diurnal IOPs were determined by use of a rebound tonometer on 2 consecutive days. Subsequently, 1 randomly chosen eye of each dog was treated topically twice daily for 5 days with 0.5% flunarizine. During this treatment period, diurnal IOPs were measured. In addition, pupillary diameter and mean arterial blood pressure (MAP) were evaluated. Serum flunarizine concentrations were measured on treatment day 5. Intraday fluctuation of IOP was analyzed by use of an ANOVA for repeated measures and a trend test. Changes in IOP from baseline values were assessed and compared with IOPs for the days of treatment. Values were also compared between treated and untreated eyes.

Results—A significant intraday fluctuation in baseline IOP was detected, which was highest in the morning (mean ± SE, 15.8 ± 0.63 mm Hg) and lowest at night (12.9 ± 0.61 mm Hg). After 2 days of treatment, there was a significant decrease in IOP from baseline values in treated (0.93 ± 0.35 mm Hg) and untreated (0.95 ± 0.34 mm Hg) eyes. There was no significant treatment effect on pupillary diameter or MAP. Flunarizine was detected in serum samples of all dogs (mean ± SD, 3.89 ± 6.36 μg/L).

Conclusions and Clinical Relevance—Topically applied flunarizine decreased IOP in dogs after 2 days of twice-daily application. This calcium-channel blocker could be effective in the treatment of dogs with glaucoma.
Ultrasound biomicroscopy of the iridocorneal angle of the eye before and after phacoemulsification and intraocular lens implantation in dogs
Authors: Rose Michelle D. , Mattoon John S. , Gemensky-Metzler Ann J. , Wilkie David A. , Rajala-Schultz Päivi J.
Published: February 2008

Objective—To compare the iridocorneal angle (ICA) and angle opening distance (AOD) in dogs with cataractous and noncataractous lenses; evaluate cataractous eyes ultrasono-graphically for association of postoperative ocular hypertension (POH) with the ICA, AOD, and postoperative echogenic anterior chamber debris; and evaluate intraobserver reliability associated with ICA and AOD measurements.

Animals—56 dogs with 102 cataracts, and 23 clinically normal dogs.

Procedures—Ultrasound biomicroscopy was performed on 102 eyes of 56 dogs before and after cataract surgery and on 46 nondilated and dilated eyes of 23 clinically normal dogs. Cataract stage, ICA, AOD, and association with POH were assessed.

Results—Cataract stage and ICA or AOD were not significantly associated; however, ICA and AOD typically decreased with increasing cataract maturity. Before and after pupillary dilation, AODs were significantly smaller in cataractous eyes than in noncataractous eyes. Before surgery, ICA and AOD in eyes without pupillary dilation were significantly associated with POH. At > 13°, odds of developing POH increased by 11% for each degree increase in the ICA. Postoperative anterior chamber debris was not associated with POH. Coefficient of variation for repeated measurements was 10% for the ICA and 9.5% for the AOD, suggesting good intraobserver reliability.

Conclusions and Clinical Relevance—In this study, dogs with larger ICA and AOD measurements before surgery were at greater risk of developing POH. This information may be useful for future studies to determine whether preventative treatment for POH administered prior to surgery may be beneficial.
Prevalences of various hemoplasma species among cats in the United States with possible hemoplasmosis
Authors: Sykes Jane E. , Terry Jeralyn C. , Lindsay LeAnn L. , Owens Sean D.
Published: February 2008

Objective—To determine prevalences of various hemoplasma species among cats in the United States with possible hemoplasmosis and identify risk factors for and clinicopathologic abnormalities associated with infection with each species.

Design—Cross-sectional study.

Animals—310 cats with cytologic evidence of hemoplasmosis (n = 9) or acute or regenerative anemia (309).

Procedures—Blood samples were tested by means of a broad-spectrum conventional PCR assay for hemoplasma DNA and by means of 3 separate species-specific real-time PCR assays for DNA from “Candidatus Mycoplasma haemominutum” (Mhm), Mycoplasma haemofelis (Mhf), and “Candidatus Mycoplasma turicensis” (Mtc).

Results—Overall prevalences of Mhm, Mhf, and Mtc infection were 23.2% (72/310), 4.8% (15/310), and 6.5% (20/310), respectively. Mixed infections were detected in 20 (6.5%) cats. Cats infected with hemoplasmas were more likely to be male than were uninfected cats. Infection with FeLV or FIV was significantly associated with infection with Mhf. Compared with uninfected cats, cats infected with Mhf had higher reticulocyte counts, nucleated RBC counts, and mean corpuscular volume; cats infected with Mhm had higher mean corpuscular volume; and cats infected with Mtc had higher monocyte counts.

Conclusions and Clinical Relevance—Results supported the suggestion that these 3 hemoplasma species commonly occur among cats in the United States and that pathogenicity of the 3 species varies.
Evaluation of surgically placed gastrojejunostomy feeding tubes in critically ill dogs
Authors: Cavanaugh Ryan P. , Kovak Janet R. , Fischetti Anthony J. , Barton Linda J. , Bergman Philip
Published: February 2008

Objective—To evaluate complications and outcomes associated with surgical placement of gastrojejunostomy feeding tubes in dogs with naturally occurring disease.

Design—Prospective study.

Animals—26 dogs.

Procedures—Multiple preoperative, intraoperative, and postoperative variables were evaluated. Daily postoperative abdominal radiographic examinations were performed to determine the presence of the following mechanical tube complications: kinking, coiling, knotting, and migration. Tube stoma abnormalities (erythema, cellulitis, and discharge) were observed daily and recorded by use of a standardized visual analog grading scale. Additionally, presence of complications was compared with median survival times.

Results—The most common indication for gastrojejunostomy tube placement was gastrointestinal disease (n = 11), with confirmed septic peritonitis in 8 of 11 dogs. Other indications for gastrojejunostomy tube placement included extrahepatic biliary surgery (n = 6) and pancreatic disease (9). Mean ± SD surgical time required for tube placement was 26 ± 14 minutes. Overall, mechanical tube complication rate was 46% (12/26), including coiling (7), migration (4), and kinking (2). Overall minor tube stoma complication rate was 77% (20/26) and included erythema (16), cellulitis (13), and discharge (17). Dislodgement or self-induced tube trauma resulted in accidental tube removal in 2 of 26 dogs, and inadvertent tube damage necessitated premature removal by the clinician in 1 of 26 dogs. Kaplan-Meier median survival time was 39 days with 13 of 26 dogs still alive.

Conclusions and Clinical Relevance—Gastrojejunostomy tube placement affords flexibility in the postoperative nutritional regimen by allowing for postgastric feeding with simultaneous access to the stomach.
Administration of doxycycline in drinking water for treatment of spiral bacterial infection in cockatiels
Authors: Evans Erika E. , Wade Laura L. , Flammer Keven
Published: February 2008

Objective—To determine efficacy of providing drinking water medicated with doxycycline for treatment of spiral bacterial infection in cockatiels.

Design—Randomized controlled clinical trial.

Animals—18 cockatiels (Nymphicus hollandicus) naturally infected with spiral bacteria.

Procedures—Spiral bacterial infection was diagnosed by means of cytologic examination of swab specimens from the choana and oropharynx. Eleven birds (treatment group) were given drinking water to which doxycycline hyclate had been added at a concentration of 400 mg/L for 30 days; the remaining 7 birds (control group) were given unmedicated water. After completion of the study, 6 control birds were treated with drinking water medicated with doxycycline for 21 days.

Results—Daily mean plasma doxycycline concentration for birds in the treatment group ranged from 2.26 to 2.86 Mg/mL (overall range, 0.83 to 4.34 Mg/mL). All treated birds were negative for spiral bacteria after treatment for 21 days and remained negative when examined 160 days after treatment ended. Control birds remained positive for spiral bacteria. Control birds treated with doxycycline after completion of the study were negative for spiral bacteria after treatment for 21 days and 30 days after treatment ended. No clinically important adverse effects were associated with treatment.

Conclusions and Clinical Relevance—Results suggested that providing drinking water to which doxycycline had been added at a concentration of 400 mg/L was effective in eliminating spiral bacterial infections in cockatiels.
Effect of preoperative administration of erythromycin or ﬂunixin meglumine on postoperative abomasal emptying rate in dairy cows undergoing surgical correction of left displacement of the abomasum
Authors: Wittek Thomas , Tischer Katja , Gieseler Tobias , Fürll Manfred , Constable Peter D.
Published: February 2008

Objective—To determine whether preoperative administration of erythromycin or flunixin meglumine altered postoperative abomasal emptying rate, rumen contraction rate, or milk production in dairy cattle undergoing surgical correction of left displacement of the abomasum (LDA).

Design—Nonrandomized, controlled clinical trial.

Animals—45 lactating Holstein-Friesian cows with LDA.

Procedures—Cows were alternately assigned to an erythromycin (10 mg/kg [4.5 mg/lb], IM), flunixin (2.2 mg/kg [1.0 mg/lb], IV), or control group (n = 15/group). Treatments were administered once 1 hour before surgical correction of LDA. D-Xylose solution (50%; 0.5 g/kg [0.23 g/lb]) was injected into the abomasal lumen during surgery, and venous blood samples were periodically obtained to determine time to maximum serum D-xylose concentration.

Results—Abomasal emptying rate was significantly faster in cows treated with erythromycin (mean ± SD time to maximum serum D-xylose concentration, 149 ± 48 minutes) than in control cows (277 ± 95 minutes) but was not significantly different between cows treated with flunixin (230 ± 49 minutes) and control cows. Cows treated with erythromycin had significantly greater milk production, relative to production before surgery, on postoperative days 1 and 2 than did control cows. Cows in the erythromycin and flunixin groups had a significantly higher rumen contraction rate on the first postoperative day than did control cows.

Conclusions and Clinical Relevance—Results suggested that preoperative administration of a single dose of erythromycin increased abomasal emptying rate, rumen contraction rate, and milk production in the immediate postoperative period in cows undergoing surgical correction of LDA.
A general approach to the analysis and description of partially polarized light in rigorous grating theory
Authors: Tervo Jani , Turunen Ismo A. , Bai Benfeng
Published: February 2008

Simple and intuitive principle is put forward to analyze the grating diffraction problem and to describe the polarization properties of diffraction orders. The method is applicable for any state of polarization of the input plane wave, including partially polarized or unpolarized fields.
Prevalence and Predictors of Need for Seating Intervention and Mobility for Persons in Long-Term Care
Authors: Bourbonniere Melissa C. , Fawcett Laura M. , Miller William C. , Garden Jennifer , Mortenson William B.
Published: February 2008

A descriptive cross-sectional study was conducted to (a) determine the prevalence of need for wheel-chair seating intervention in two long-term care facilities in Vancouver, BC, (b) determine the extent of the residents' independent mobility within these facilities, and (c) explore the relationship between proper wheel-chair seating and positioning and independent mobility. The study population comprised 99 wheel-chair-using older adults. Four trained raters assessed need for seating intervention, using the Seating Identification Tool, and quantified extent and frequency of wheel-chair mobility, using the Nursing Home Life-Space Diameter. Results indicated that (a) there was a low need (overall 22%) for wheel-chair seating intervention in the two facilities, (b) half of the residents were independently mobile in their own rooms and on their units, but independent mobility decreased when greater distances needed to be travelled, and (c) the need for wheel-chair seating intervention was the only significant predictor of extent of independent mobility. These findings suggest that, where there are dedicated staff and equipment resources, the need for wheel-chair seating intervention can be minimized and independent mobility for long-term care residents maximized.
Indicators of Home Care Use in Urban and Rural Settings
Authors: Mitchell Lori A. , Strain Laurel A. , Blandford Audrey A.
Published: February 2008

This study employs a longitudinal design to examine rural–urban differences in home care service use over time, drawing on data from the Manitoba Study of Health and Aging (MSHA). Characteristics of community-dwelling, cognitively intact adults aged 65 years or older not receiving home care services in the province of Manitoba (n = 855) were collected in 1991/1992. Place of residence was categorized as urban/small-town zone or predominantly rural area. A 5-year follow-up determined subsequent home care use. Urban residents were more likely to receive home care than those in small-town zones or predominantly rural areas. Characteristics associated with use differed according to place of residence, with the exception of baseline physical functioning and changes in physical functioning that consistently emerged as significant. Directions for future research are discussed.
Réjean Hébert, André Tourigny, and Maxime Gagnon (Eds.). Integrated Service Delivery to Ensure Persons' Functional Autonomy. Saint-Hyacinthe, QC: Edisem, 2005.
Authors: Dubois Carl-Ardy
Published: February 2008

Cet ouvrage porte sur PRISMA, un programme de recherche sur l'intégration des services de maintien de l'autonomie. S'appuyant sur un partenariat entre chercheurs, gestionnaires et cliniciens, PRISMA a permis de développer, d'implanter et d'évaluer un modèle organisationnel original visant à assurer l'intégration des soins aux personnes âgées en perte d'autonomie. Les mécanismes et outils inhérents au programme incluent, entre autres, une porte d'entrée unique, un processus de gestion par cas; un plan de service individualisé et un ensemble de mécanismes de gouvernance. En plus de fournir une gamme d'options pour renforcer l'intégration, cet ouvrage illustre comment une action concertée entre chercheurs et praticiens peut faciliter des changements organisationnels.
Rockfill Embankment Settlement
Authors: Anderson Scott A. , LaFronz Nicholas J.
Published: February 2008

The Hoover Dam Bypass project (US-93) crosses the Colorado River between Arizona and Nevada below Hoover Dam, 30 mi southeast of Las Vegas, Nevada. The Arizona approach to the river includes the seven-span, 900-ft long Sugarloaf Mountain Bridge. The east bridge abutment footing is supported on a welded-wire–reinforced, special embankment fill zone within a 130-ft high rockfill embankment. Reinforced zone backfill consists of 4-in. maximum size select granular backfill; the remainder of the embankment consists of 2-ft maximum size rock. Backfill and rockfill were obtained from project roadway cuts, and construction and acceptance of the reinforced zone and rockfill embankment were in accordance with FHWA standard specifications and project special provisions. Postconstruction settlement of the embankment was monitored for 2 years with conventional survey monuments on abutment wingwalls and the embankment and multipoint borehole extensometers (MPBX) in the roadway shoulders. The monitoring period included 3 months before placement of the closure span and deck. Roughly 1 in. of settlement beneath the reinforced fill was measured during construction, with an additional 1/2 in. of settlement within 2 years after fill placement. Postconstruction settlement of the wingwalls was approximately 1 in. The rate of settlement decreased through the 2-year period, and settlement from construction and self-weight is nearly complete. Use of the MPBX was deemed partially successful in this application.
Permanent Deformation and Critical Stress of Cohesive Soil under Repeated Loading
Authors: Yang Shu-Rong , Huang Wei-Hsing
Published: February 2008

The accumulated plastic strain of subgrade soils under repeated traffic loading is an important consideration in designing pavements that resist rutting. This study presents a laboratory evaluation of the plastic strain behavior of a cohesive soil using repeated load triaxial tests. The stress–strain response of the soil under repeated loading was determined at various deviator stress levels and carefully examined. The accumulated plastic strain and the plastic strain rate were used to characterize the shakedown behavior of a cohesive soil. Approaches to determining the critical stress that defines the boundary between stable and unstable conditions under repeated loading were developed. An equation for predicting the critical stress with varying water contents was induced from the presented data. In addition, a correlation between the accumulated plastic strain and the number of load repetitions was established with a power law model. Cohesive subgrade at high water contents was found to be liable to develop excessive plastic strain under repeated loading.
Mechanistic Classification of Unbound Materials
Authors: Khogali Walaa E. I. , Mohamed El Hussein H.
Published: February 2008

The effectiveness of an approach, based on the use of default resilient modulus (Mr) values in providing input to the Mechanistic–Empirical Pavement Design Guide (MEPDG) developed under the NCHRP 1–37A project, was evaluated. The process is intended to assist users of the guide in estimating the Mr of an unbound material based on its AASHTO soil class. Assessment conducted at the National Research Council Canada (NRC) involved comparing values of the parameter determined in the laboratory using the AASHTO protocol with default values included in MEPDG. Comparison revealed that the proposed default values frequently overestimate the value of the Mr parameter, hence yielding inadequate layer design. Examination of the AASHTO Mr test revealed that the procedure does not account for permanent deformations that accumulate during the laboratory test. These findings prompted the NRC team to develop a different approach for estimating the Mr parameter. The new approach yielded a mechanistic soil classification system based on the material response captured in the laboratory. A practical procedure for implementing the new mechanistic classification system was facilitated by establishing correlations between physical and mechanical properties of the materials. These correlations were found to be more accurate in estimating the Mr parameter and were expected to produce better design when used as input for running the MEPDG model.
Initial Findings on Skid Resistance of Unpaved Roads
Authors: Lea Jeremy D. , Jones David J.
Published: February 2008

Unpaved roads have a dynamic surface, which can make it difficult to predict the skid resistance of a section for use in geometric design and gravel selection and to schedule maintenance. This investigation showed that there are three mechanisms for skidding on unpaved roads: intersurface friction, sliding on a thin layer of loose material, and plowing through a thick layer of loose material. The main surface and material properties affecting skid resistance are the stoniness severity and extent, the severity and extent of raveling, and the amount of loose material in the 0.850-mm to 2.00-mm range on the surface. The range of coefficients of friction for unpaved roads is from 0.40 to 0.85, with the lower value being conservative.
Gravel Roads Surface Performance Modeling
Authors: Huntington George , Ksaibati Khaled
Published: February 2008

Twenty gravel road study sections at 10 sites in north-central Wyoming were monitored from September 2005 through June 2006. Windshield or mobile, visual survey ratings of the sections and field measurements were taken weekly. Surfacing gravel samples were collected, and their gradations were determined. Traffic speeds and volumes by class were collected with a two-tube system. (A two-tube system counts traffic by receiving signals from two tubes placed 8 ft apart across the road. By a comparison of the times at which signals are received from each tube, the speed of the traffic can be determined, as can the number and spacing of axles.) Statistical analyses generated regression models that allowed the prediction of the service life of an unmaintained gravel road. Traffic speeds, traffic volumes, and surfacing gravel properties were shown to have the greatest influence on gravel roads’ deterioration rates. For these typical Wyoming county roads with good geometry, good drainage, and adequate gravel thicknesses, the typical failure mode was shown to be either potholes or washboards (corrugations). The typical life of gravel roads without maintenance was shown to be in the range of several months to 1 year. Climatic effects were shown to be related to precipitation more than seasonality, at least in Wyoming's dry–freeze climate.
Assessment of Debonding in Concrete Slabs Using Seismic Methods
Authors: Celaya Manuel , Shokouhi Parisa , Nazarian Soheil
Published: February 2008

A combination of impact echo (IE) and ultrasonic surface waves techniques was used to locate the debonding in concrete slabs at several locations on TX-225 near Houston, Texas. A portable seismic pavement analyzer (PSPA), a hand-held automated system, was used for seismic data collection in the field. Field measurements are presented in the time and frequency domains in the form of time records and amplitude spectra. The characteristics differentiating the response (time records) of fully bonded and debonded slabs are discussed. The frequency domain (spectral) analysis was shown to be superior to time domain analysis in describing the response of slabs in marginal condition (i.e., slabs showing partial debonding or horizontal cracks). On the basis of the spectral characteristics of their surface response, the slabs were categorized into four different categories: good, fair, poor, and bad conditions (in terms of debonding). Time–frequency analysis was proposed as a complementary tool for the analysis of IE signals. The test records were analyzed by a time–frequency analysis method and are presented in a two-dimensional time–frequency plane. The advantages of using a time–frequency technique over a spectral analysis are described. Finally, the debonding assessments made on the basis of PSPA measurements were verified by ground truth data.
Two-Step Fracture Mechanics–Based Approach to Assess Early-Age Delamination Distress
Authors: Liu Juanyu , Zhang Xiong , Zollinger Dan G.
Published: February 2008

The development of a comprehensive, early-age delamination model requires an integration of interfacial strength of the aggregate–mortar interface and environmental, materials, and construction effects. Previous research has led to the establishment of the model's mechanism that can be characterized with engineering mechanics. However, fracture mechanics theory, which is more suitable to represent the delamination process, has not been widely applied to concrete pavement analysis. A two-step fracture mechanics–based model was developed to predict the occurrence potential of delamination in continuously reinforced concrete pavements. The model is based on the comparison between the stress intensity factor (KI) and fracture toughness (KIC). The development of the KI of concrete at an early age was simulated through a two-step numerical analysis, including (a) a coupled thermal–hygro analysis to predict the temperature and moisture profiles and the associated material properties and (b) a coupled hygro–mechanical stress analysis to predict the differential drying shrinkage-induced stress. This model addressed the integration of effects of environment, materials, and construction factors through key parameters that included moisture diffusivity, shrinkage strain gradient, pavement thickness, and elastic modulus of concrete.
Genetic Algorithms–Based Network Optimization System with Multiple Objectives
Authors: Wang Kelvin C. P. , Nguyen Vu , Zaniewski John P.
Published: February 2008

In any engineering decision-making process, it is a common problem to formulate a model with multiple objectives and to obtain proper answers. If the objectives are opposing, the problem then becomes finding the best possible design that identifies the best compromise between the opposing objectives. In a pavement management system of a state highway agency, engineers constantly struggle with performance requirements and limited budget. This situation results in an optimization problem with two conflicting objectives. The underlying algorithm of the classic network optimization system was coupled with genetic algorithm (GA) techniques to minimize budget and maximize performance of highway pavement networks in rehabilitation planning. GA is generally considered a powerful methodology in solving multiobjective problems. The data analysis demonstrated that the GA technique is applicable in producing workable solutions to a multiobjective pavement management problem.
Ground Proving Three Seismic Refraction Tomography Programs
Authors: Hiltunen Dennis R. , Hudyma Nick , Quigley Timothy P. , Samakur Chandra
Published: February 2008

During a recent ground-proving exercise at the shared University of North Florida and University of Florida karstic limestone geophysical and ground-proving test site in central Florida, the limestone bedrock surface was mapped along several survey lines with both intrusive and geophysical techniques. Analyses of the site investigation data revealed a highly erratic limestone bedrock surface, which is common in karst terrane. Analysis of seismic refraction data demonstrated that three commercially available refraction tomography software systems can reveal the undulating bedrock surface. However, the tomography data revealed marked differences in the compression wave velocities at the top of the bedrock surface at various locations along one of the survey lines. Compression wave velocities were highest within slots or valleys and lowest at the tops of blocks or pinnacles. This variability is attributed to the geologic history of the limestone, which includes how the limestone was formed and how the limestone weathered. Ground proving via cone penetration tests and geotechnical borings appears to corroborate this finding and demonstrates the importance of measuring multiple material parameters during site characterization activities in complex terranes.
Monod Kinetics for Aerobic Biodegradation of Calcium Magnesium Acetate
Authors: Ostendorf David W. , Rotaru Camelia , Wisdom K. Blair
Published: February 2008

Monod kinetics were used to recalibrate published sets of soil microcosm data that document the aerobic biodegradation of calcium magnesium acetate in a highway shoulder. The natural attenuation is important because acetate can exert an appreciable oxygen demand on ground-water if it persists from the ground surface to the water table. Biomass dynamics were modeled, as well as acetate degradation, in the assumed abundance of oxygen and nutrients. The maximum specific growth rate (μM) and half saturation constant (KS) quantify the ability of an individual aerobe to degrade acetate and accordingly calibrate microcosm data from all locations in the shoulder. Thirty-two microcosm sets from SR-25 in southeastern Massachusetts yielded a calibrated μM of 0.00133 h[minus]1 and a KS of 0.087 kg acetate/m3 soil moisture. Calibrated (not measured) initial biomass concentrations varied from 10 to 1,000 μg biomass/g dry soil, with the largest values near the surface of the loamy sand cover layer and the smallest values above the capillary fringe consisting of uniform sand. The initial biomass concentrations and Monod kinetics yielded reaction rates consistent with field scale estimates of acetate degradation.
Analysis of Road Risk by Age and Gender Category
Authors: Van den Bossche Filip A. M. , Wets Geert , Brijs Tom
Published: February 2008

A road safety analysis for different age and gender categories of road users is introduced. In contrast to many previous studies, the time series of road crashes by age and gender category is considered. The objective is to analyze Belgian data on the yearly number of fatalities for age and gender groups by using a decomposition of the number of fatalities in terms of exposure and risk in a time series perspective. For each category, a state space time series model is developed for the risk, which is defined in this study as the number of fatalities per capita. It was found that road risk is changing over age groups according to a U-shaped curve and that men generally have a higher risk than women. Further, the risk is decreasing over time but not at the same rate for all age and gender groups. The highest yearly reduction in risk is found for the oldest and youngest road users. The models also are useful to assess the attainability of formulated road safety targets, which makes them useful policy instruments. Especially for young men, the reduction in road risk is not in line with Belgian and Flemish policy expectations.
Investigating Effect of Holidays on Daily Traffic Counts
Authors: Cools Mario , Moons Elke , Wets Geert
Published: February 2008

Different modeling philosophies are explored to explain and to forecast daily traffic counts. The main objectives of this study are the analysis of the impact of holidays on daily traffic and the forecasting of future traffic counts. Data from single inductive-loop detectors, collected in 2003, 2004, and 2005, were used for the analysis. The different models investigated showed that the variation in daily traffic counts could be explained by weekly cycles. The Box-Tiao modeling approach was applied to quantify the effect of holidays on daily traffic. The results showed that traffic counts were significantly lower for holiday periods. When the different modeling techniques were compared with a large forecast horizon, Box-Tiao modeling clearly outperformed the other modeling strategies. Simultaneous modeling of both the underlying reasons of travel and the revealed traffic patterns certainly is a challenge for further research.
Investigation of Regression-to-Mean Effect in Traffic Safety Evaluation Methodologies
Authors: Sharma Shyam L. , Datta Tapan K.
Published: February 2008

Observational before-and-after safety evaluations have been commonly used to determine the effectiveness of safety improvements applied to high-crash locations. Such evaluations may typically be affected by regression-to-mean (RTM) bias. This research compares the effectiveness of low-cost safety improvements applied to several high-crash intersections in the cities of Detroit and Grand Rapids, Michigan, and examines the RTM effects by using various safety evaluation methodologies. Some previous studies suggest that before-and-after studies are always biased. It is also claimed that the observed number of crashes cannot be used to determine the effectiveness of safety improvements, and the use of the empirical Bayes (EB) method is suggested. This research examines the RTM effects by using before-and-after studies, before-and-after studies with control sites, and two different variants of the EB method. The research reveals that the expected crash frequencies computed by various evaluation methods do not differ significantly when 3 to 5 years' worth of traffic crash data are used. The deviations of the expected crash frequencies with the before-and-after methods and the EB method are computed to compare the RTM effects for each additional year of traffic crash data used in the evaluation. This research reveals that before-and-after studies produce results similar to those of the EB method, and the RTM effect becomes insignificant when 3 or more years' worth of traffic crash data are used in the evaluation of high-crash locations.