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Pharmacokinetic analysis of antimicrobials and an anthelmintic agent in alpacas and llamas with theoretical applications
Get PDFThe pharmacokinetics of two antimicrobials were investigated in alpacas. Six healthy alpacas were each administered a single dose of 10 mg/kg of oxytetracycline by IV injection and IM injection. In addition, a single dose of 20 mg/kg of florfenicol by IV administration was given to alpacas in a separate study. The pharmacokinetic parameters of oxytetracycline and florfenicol in alpacas were compared to the results previously obtained in llamas. There were significant differences between llamas and alpacas in several of oxytetracycline pharmacokinetic parameters but there were no significant differences in all of florfenicol pharmacokinetic parameters in these two animals. It can be concluded that llamas and alpacas have different oxytetracycline disposition kinetics while they have similar disposition kinetics of florfenicol. The pharmacokinetics of clorsulon, a narrow-spectrum anthelmintic agent, was investigated in llamas following oral administration at a single dose of 14 mg/kg. The plasma levels of clorsulon produced by this dose was lower than the values reported in the clorsulon pharmacokinetic studies carried out in sheep and goats following oral administration at a single dose of 7 mg/kg This suggests the entire dose of clorsulon is not absorbed in llamas. Since the differential equations describing one-compartment system with first-order input and two-compartment system after IV administration with nonlinear elimination kinetics cannot be solved, there is no mathematical expression for the AUC for drugs following these models. The AUC values calculated from the proposed preliminary AUC equations for drugs following these models were compared to the AUC calculated using the trapezoidal rule method based on computer-generated data using the fourth-order Runge-Kutta method. Except for a few exceptions, the predicted AUC from the proposed equations matched the values calculated from the theoretically generated data
Carbon fluxes across three climatically-distinct forest chronosequences in Oregon
Get PDFBiometric and gas exchange techniques were used to measure soil respiration (soil surface CO₂ efflux) and NEP (Net Ecosystem Production) across three climatically-distinct forest chronosequences in Oregon. Results indicate significant forest type, age, and forest type x age interaction effects on annual soil respiration. A regional age class distribution skewed away from the youngest and oldest forests moderate regional variation in soil respiration. Sensitivity analysis suggests that the regional variation in annual soil respiration is most dependent on summer base rates (i.e. soil respiration normalized to a common temperature) and much less dependent on site-specific temperature response curve (to which annual rates are relatively insensitive) and soil degree-days (which vary only 10% among sites). Across all plots, annual soil respiration was not correlated with aboveground net primary production (ANPP, R²=O.06, p>0.1) but it was correlated with belowground net primary production (R²=0.43, p<0.001). Despite the wide range in temperature and precipitation regimes experienced by these forests, all exhibited similar soil respiration per unit fine root biomass, (R²=0.45, p<0.00l). Forest floor mass and mineral soil carbon were only weakly coupled to soil respiration (R²=0.14, and 0.12, respectively). Trends between soil respiration, production, and root mass among age classes within cover type were inconsistent and do not always reflect cross-site trends. NEP was highly negative immediately following stand replacing disturbance in all forests and recovered to positive values by 10, 20, and 30 years of age for the mild and mesic Coast Range, West Cascades and East Cascades, respectively. The response of stand-level NEP to individual disturbance events is greater than that attributable to edaphoclimatic differences between forest type. However, when successional trends in NEP are weighted by current age class distributions, the variability in landscape-level NEP attributable to whole disturbance regimes is equivalent to that attributable regional edaphoclimatic differences between forest types. Simulations of age class distribution under varying disturbance frequencies suggest that the sensitivity of landscape-level NEP to changes in disturbance regime varies among forest types and is linked to both remnant detritus and photosynthetic recovery rate that are partly a function of long-term edaphoclimatic differences
Species identification of Klamath Basin suckers (Pisces : Catostomidae) and an assessment of hybridization using anonymous nuclear loci
Get PDFLow copy number anonymous nuclear loci were used to search for species markers in four species of Klamath Basin suckers. We sequenced 28 randomly chosen loci representing 10,421 bp; 21 loci were similar to sequences in GenBank. Eight fixed sequence differences were found among Klamath species. Locus 120 contained rare but diagnostic markers for Deltistes luxatus and for Catostomus rimiculus. Locus 4 also contained three rare but unique sites in Catostomus rimiculus. No sequence differences were found between Chasmistes brevirostris and Catostomus snyderi. Loci 4 and 120 exhibited allele frequency differences between Rogue River C. rimiculus and all Klamath Basin suckers. Genotype BB of locus 4 was a fixed diagnostic marker and genotype BB of locus 120 was a frequency dependent marker for Rogue C. rimiculus. Although Klamath suckers represent three genera, very limited variation was found among 10,431 base pairs. We examined phylogenetic patterns of five loci in eleven catostomid genera and 25 species to determine if the homogeneity in the Upper Klamath Basin was due to massive hybridization and introgression or to retention of ancestral sequences. Two loci with no similarity to GenBank sequences (non-coding loci) and three loci with substantial similarity to GenBank sequences (coding loci) gave similar results, providing support for various subfamilies and tribes, more support for eastern genera and little support for western genera. Each locus was a mosaic of species or population markers, sometimes providing discriminatory power for allopatric populations of a species, such as C. macrocheilus, while not discriminating other species. Upper Klamath Basin species were noteworthy in their lack of autapomorphies, but had similar numbers of derived informative sites as other catostomins. Upper Klamath Basin species consistently shared ancestral or equivocal informative sites either with moxostomatins or a variable group of western species and shared derived sites with other western species, especially C. occidentalis. The data suggest that Upper Klamath Basin species have retained a largely ancestral genome at these loci. Thus, the failure of this technique to uncover significant variation in Upper Klamath Basin species may be a reflection of their plesiomorphic genome at these loci and not necessarily hybridization
Surimi wash water treatment by chitosan-alginate complexes : effect of molecular weight and degree of deacetylation of chitosan and nutritional evaluation of solids recovered by the treatment
Get PDFSoluble surimi wash water (SWW) proteins could be recovered using chitosan (Chi) complexed with alginate (Chi-Alg) generating co-products for feed formulations. Chi with a degree of deacetylation (DD) of 84% complexed with Alg at a mixing ratio (MR) of 0.2 was used to study Chi-Alg concentration and treatment time protein recovery effects. Insoluble SWW solids were removed by centrifugation and the supernatant was then adjusted to pH 6. Flocculation at 20°C using Chi-Alg at 20, 40, 100 and 150 mg/L SWW was aided by 5 mm agitation and holding for 30 mm, 1h and 24h. Concentration had an effect between low (20 and 40 mg/L) and high (100 and 150 mg/L) levels. Time had an effect between 30 min and 1h but not between 1 and 24 h. Turbidity reduction was affected only by concentration. 100 mg Chi-Alg/L SWW for 1 h achieved 83% protein adsorption and 97% turbidity reduction while lower concentrations yielding higher adsorption required longer times. Fourier Transform Infrared (FTIR) analysis of untreated and Chi-Alg treated SWW solids confirmed protein adsorption. Amide band areas normalized against a common 3005-2880 cm⁻¹ region confirmed the high protein recovery by 100 mg Chi-Alg/L SWW. Six Chi samples differing in molecular weight (MW) and degree of deacetylation (DD) were tested to recover soluble SWW solids using 20, 40, and 100 mg Chi-Alg/L SWW (0.2 MR, 1h). High (94%, 93%) and low (75%) DD chitosan had lower protein adsorption (73-75%) when compared to the intermediate (84%) DD chitosan (74-83%). Intermediate DD and high MW Chi seemed to perform better; however, SY-1000 with 94% DD did not follow this trend (79-86% protein adsorption, 85-92% turbidity reduction). Insoluble SWW (P1) and soluble solids (P2) recovered using 150 mg Chi- Alg/L SWW contained 61.4 and 73.1% protein, respectively. Rat diets formulated with 10% protein substitution by P1 and 10% and 15% by P2 had acceptability and protein efficiency ratios (PER) as high as the casein control with no deleterious effects. Rat diets with 100% P2 protein substitution showed higher PER and net protein ratio than the casein control with no deleterious effects. Protein recovered from SWW using Chi-Alg has the potential to be used in commercial feed formulations
Exploring Inclusive and Equitable Pedagogies: Creating Space for All Learners, Section 4: Introduction
No full textFrom: Exploring Inclusive & Equitable Pedagogies: Creating Space for All Learner
Using demographic and clinical variables to predict the length of stay of "incompetent to stand trial" patients
Get PDFIn Oregon, "Incompetent to Stand Trial (1ST) Patients" were observed to be increasing in number, remaining in the hospital longer, and costing more to treat. A study was designed to investigate variables that could be used to predict their length of stay at Oregon State Hospital. Data for thirteen independent variables (gender, age, having an Axis I psychosis level diagnosis, having an Axis I substance-related diagnosis, having an Axis II personality disorder diagnosis, evidence of involuntary medications, being on atypical medications at discharge, number of seclusion and restraint events, number of felony charges, number of misdemeanor charges, and number of inter-ward transfers) and one dependent variable (length of stay) were analyzed for 198 1ST patients discharged from Oregon State Hospital between January, 1999 and December, 2001. Bivariate correlations for all variables, and length of stay (LOS) means for all levels of each variable were examined and discussed. A standard multiple regression analysis was performed. The regression model accounted for 36.5% (32.7% adjusted) of the variability in (log) LOS. R for regression was found to be significantly different from zero. Five variables were found to be significant contributors to explaining the variability in (log) LOS: (square root) number of inter-ward transfers (16%), gender (5.8%), evidence of involuntary medications (5.2%), (square root) number of felony charges (2.8%), and (square root) number of seclusion and restraint events (1.6%). Despite accounting for more variability in LOS than several previous studies with psychiatric patients, 67.3% of the variability was unaccounted for by the regression model. Unstandardized regression coefficients for untransformed variables were interpreted, revealing that gender, number of inter-ward transfers, and evidence of involuntary medications significantly predicted the largest increases in LOS. Recommendations were made for further research related to LOS of 1ST patients
Nonlinear finite element analysis of reinforced concrete structures strengthened with FRP laminates
Get PDFThe Horsetail Creek (HC) bridge is an example of an Oregon bridge that was classified as structurally deficient and was not designed to withstand earthquake (EQ) excitations. A fiber-reinforced polymer (FRP) rehabilitation was performed on the HC bridge to increase flexural and shear capacities for traffic loads. However, a seismic retrofit has not yet been accomplished for this bridge. Fully three-dimensional finite element (FE) models are developed to simulate and examine the structural behavior of both full-size reinforced concrete (RC) beams and the HC bridge using ANSYS. FE analyses are compared with tests of full-scale beams replicating the transverse beams of the HC bridge before and after FRP strengthening from linear and nonlinear ranges up to failure. The FE models can effectively predict the behavior of the beams, and analytical and experimental results correlate very well. For the FE analyses of the HC bridge, soil-structure interface modeling is incorporated to replicate the actual bridge boundary conditions. Truck loadings are applied to the FE model at different locations, as in the actual bridge test. A sensitivity study is performed by varying uncertain bridge parameters to develop an FE bridge model best representing the actual bridge conditions. The optimal FE model obtained from the sensitivity study can accurately predict the magnitudes and trends in the strains. After an optimal FE bridge model is established, a performance evaluation on the FRP strengthening of the HC bridge is conducted. Both unstrengthened and FRP-strengthened bridge models are subjected to two different types of loading; i.e., scaled gravity and scaled truck loads to failure. Comparisons of results show the improvement in structural performance due to FRP strengthening. A seismic risk-related investigation of the HC bridge is also carried out. Nonlinear time-history analyses are performed using EQ acceleration-time histories applied to the HC bridge model. The ground motions are appropriate to the Pacific Northwest site and scaled so that the response spectrum, within natural periods of interest, matches the 1996 AASHTO design response spectrum. Based on the analytical results, colunm confinement is recommended to increase ductility and reduce potential for substructure collapse in future seismic events
The structural relationship among gender role conflict, social support and health behavior in older men
Get PDFInquiry into the cause of men's premature mortality has been historically framed in a biological deterministic perspective. This research takes an alternative view whereby the possible interactions of psychosocial variables with men's health promoting and health seeking behaviors are examined using cross-sectional survey data with older men. Specifically, this research explored the relationships among gender role conflict, perceived social support, and older men's health behaviors. Traditional pencil/paper (n=256) and electronic (n=147) surveys were completed by older men aged 40 and over selected from university alumni of a large western university. As the Gender Role Conflict Scale (O'Neil et al., 1986) had not been previously validated within a sample of older men, confirmatory factor analysis was used to verify that the instrument performed as well or better in older men than in previous samples of college age men. Secondly, multiple regression and canonical correlation was used to find that gender role conflict predicts less perceived social support in our sample. Moreover, restrictive emotionality appears to have the greatest influence on perceived social support and interacts greatest with emotional/informational support. Last, structural equation modeling was used to validate the findings from the regression analysis as well as determine that perceived social support predicts health promoting behaviors in our sample. While there did not appear to be a direct effect of gender role conflict on health seeking behaviors as hypothesized, health promoting behaviors did predict health seeking among these men. The findings from this study are an important step into examining how the gender role socialization of men may relate to health through protective and harmful behaviors supported by normative standards. This research allows health researchers to examine gender role conflict in older men through the validation of an instrument, and suggests that men who are highly socialized into male role norms are less likely to benefit from the well documented stress buffering effects of social support
The quantitative evaluation of radiological workplace indicators
Get PDFTwo research studies at the U.S. Department of Energy's Hanford Site and Rocky Flats Environmental Technology Site (RFETS) explore the quantitative relationship between surface contamination, airborne radioactivity, worker intakes, and subsequent dose. In the first study, resuspension factors are developed and evaluated at the U.S. Department of Energy's (U.S. DOE) Hanford facility currently undergoing decommissioning, decontamination, and demolition. Resuspension factors are developed from historical breathing zone and general area grab air sample data coupled temporally and spatially with loose surface contamination data. A Monte Carlo approach termed the proportional contribution method (PCM) is used to innovatively calculate the uncertainty of a resuspension factor by randomly assigning a proportional contribution of each surface contamination survey smear data point to airborne radioactivity. For the purpose of work planning, site procedures require that radiation protection personnel use a l x 10⁻⁵ m ⁻¹ resuspension factor. Monte Carlo simulations result in geometric mean general area grab and breathing zone air sample resuspension factors of 2.6 × 10⁻⁵m ⁻¹ (× or ÷) 12 and 4.7 x 10⁻⁶ (× or ÷) 17, respectively. Results of this study suggest the 1 × 10⁻⁵ m ⁻¹ resuspension factor routinely used at the study facility is a reasonable estimate. The second study investigates the accuracy of the nasal swab test in predicting acute intakes at RFETS. Ratios of intakes confirmed by bioassay (Bq) to nasal swab results (Bq) are developed for 323 acute intake investigations. A novel biostatistics approach is used to assess the accuracy and predictive value of the nasal swab diagnostic test in predicting acute intakes. The maximum upper bound ratio of intakes confirmed by bioassay > DL to nasal swab results > DL is 1,295. A linear regression revealed the nasal smear intakes are weakly correlated (R = 0.25 and R²= 0.063) to confirmed intakes. The sensitivity of the nasal swab test is low at 0.166, with a false negative result of 0.834. The specificity of the nasal swab test is 0.774, with a false positive result of 0.226. The predictive value positive of the nasal swab test is 0.600. The low sensitivity and predictive values, in the context of the study population, suggest the nasal swab diagnostic test does not add any useful information in predicting intakes
Entomopathogenic nematodes for biological control of the Colorado potato beetle, Leptinotarsa decemlineata (Say)
No full textThe Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say), is the most devastating foliage-feeding pest of potatoes in the United States. Potential biological control agents include the nematodes Heterorhabditis marelatus Liu & Berry and Steinernema riobrave Cabanillas, Poinar & Raulston, which provided nearly 100% CPB control in previous laboratory trials. In the present study, laboratory assays tested survival and infection by the two species under the soil temperatures CPB are exposed to, from 4-37°C. H. marelatus survived from 4-31°C, and S. riobrave from 4-37°C. Both species infected and developed in waxworm hosts from 13-31°C, but H. marelatus rarely infected hosts above 25°C, and S. riobrave rarely infected hosts below 19°C. H. marelatus infected an average of 5.8% of hosts from 13- 31°C, whereas S. riobrave infected 1.4%. Although H. marelatus could not survive at temperatures as high as S. riobrave. H. marelatus infected more hosts so is preferable for use in CPB control. Heterorhabditis marelatus rarely reproduced in CPB. Preliminary laboratory trials suggested the addition of nitrogen to CPB host plants improved nematode reproduction. Field studies testing nitrogen fertilizer effects on nematode reproduction in CPB indicated that increasing nitrogen from 226 kg/ha to 678 kg/ha produced 25% higher foliar levels of the alkaloids solanine and chaconine. However, the increased alkaloids did not affect nematode infection of, nor reproduction in, CPB prepupae. Nematodes applied to field plot soil at 50 infective juveniles/cm² reduced adult CPB by 50%, and increased numbers of dead prepupae in soil samples up to five times more than in non-nematode plots. Laboratory studies of H. marelatus and its symbiotic bacteria in CPB hemolymph indicated that immune responses did not limit nematode reproduction. A 58kD CPB hemolymph protein apparently caused the symbiotic bacteria to switch to the secondary form, which does not produce antibiotics and enzymes necessary for nematode growth and reproduction. Despite heat denaturation of the protein, the nematodes did not reproduce unless lipids were added to the hemolymph. Therefore, while H. marelatus may provide high levels of CPB control, nutritional constraints on the nematode and its bacteria inhibit reproduction in CPB and limit long-term multi-generation control