Effects of Radial Thermal Gradients in HPLC

Due to the widespread use of chromatography, improving efficiency in chromatography is continually an area of interest. Researchers have suggested that the method of column temperature control influences efficiency. To insure reproducible retention times, HPLC columns are often thermostated with a water jacket. Under such conditions, however, a radial thermal gradient may arise from the heat produced by friction between the stationary and mobile phases. If the core of the column is allowed to warm up while the walls are kept at a constant temperature, the solute in the core of the column will elute faster than will that at the walls. This phenomenon creates a wider band of solute leaving the column, which results in poorer efficiency. Insulating the column should eliminate the radial thermal gradient because the column is allowed to heat up uniformly, and air thermostating the column should reduce the gradient. Experiments indicate that the insulated and air thermostated columns yield better efficiencies than does the water thermostated column. A mathematical model generated to compare the efficiencies of columns that contain radial thermal gradients with those that do not shows that radial thermal gradients significantly reduce efficiency

See and be seen: Young adult refugee literature in the high school curriculum

According to the United Nations High Commissioner for Refugees, there are more than 25 million refugees in the world today, over half of whom are under the age of 18. As these young people adapt to new schools and communities, it is essential that all students have opportunities to see themselves represented in literature and to develop understandings of the experiences of others. This project provides an analysis of young adult refugee literature with a unit plan for application of texts in a ninth-grade Virginia English classroom, stressing the importance of education as a tool for awareness, reflection, and empathy

Master of Science

thesisMany contemporary work, school, and home environments produce attentional fatigue. One way to recover from such attentional fatigue is to place oneself in environments or settings that promote feelings of tranquility. One way to begin systematic study of environment-tranquility relations is to frame research within Attention Restoration Theory (ART). This theory is based on environmental supports that allow one to shift from directed or focused attention to involuntary forms of attention, thus allowing fatigued attentional capacities to rest. ART proposes that four judgments of environmental configurations are important to creating restorative experiences. These are environments that afford disengaging from one‘s normal physical environment, cognitive tasks, or cares and concerns (called "being away"), fascination, extent, and goal compatibility. These same variables, although more refined and subtly manipulated, may also promote experiences of tranquility. Two variables, within Attention Restoration Theory, that may be particularly associated with promoting experiences of tranquility are fascination and extent. Fascination can exist at different levels in a setting, and some levels may grab and hold attention in an undramatic way, leaving "cognitive space" for gentle contemplation and reflection. On the face, they seem like settings that should promote tranquil experiences. Extent, the organized patterns in an environment that make it seem to "hang together," may interact with fascination to produce tranquil states. This is because momentarily and unrelated fascinating stimuli will not hold the mind in a gently focused manner long enough for low activation, yet pleasantly valenced states associated with tranquility to accrue. Thus, fascination and extent should interact in such a way that environments judged as containing fascination and extent should promote the greatest states of tranquility. Therefore, the purpose of this study was to examine the interactive effects of fascination and extent on judgments of tranquility associated with scenes of natural landscapes. Participants rated 12 photos of environments containing different levels of fascination and extent. The design was a repeated measures and hierarchal linear modeling using HLM, 6.0 was used to test the study‘s hypothesis. Results show that both fascination and extent were positively associated with tranquility

AN ALTERNATIVE FOR MIXED MODEL ANALYSES OF LARGE, MESSY DATA SETS (MTDFREML)

Portable Fortran based programs (MTDFREML) were developed using a derivative-free algorithm to obtain REML estimates of (co)variance components. Computations are based on Henderson\u27s mixed model equations for multiple-trait models with missing observations on some traits and incorporation of relationships among relatives. Many fixed and random factors are allowed with number of levels dependent on computer memory. Data sets with more than 40,000 genetic effects have been analyzed. Options allow solving MME at convergence. Constraints are automatically imposed. Expectations, standard errors of contrasts of solutions for fixed effects and prediction error variances of solutions for random effects can be obtained. Dimensions can be changed to match data with computer capability. A Fortran compiler is necessary. No fee is charged but the University of Waterloo must certify a license has been obtained for sparse matrix subroutines (SPARSPAK) used in the program. As an example, birth weights of 4891 progeny of 389 sires nested within 12 breeds and of 2893 dams nested within 3 breeds of dam were analyzed to estimate components of variance due to sires and dams and to estimate differences among breeds of sires. For MTDFREML the analysis was trivial but for PROC MIXED the analysis was impossible unless dams were dropped from the model

Characterization of Horse Use in Therapeutic Horseback Riding Programs in the United States: A Pilot Survey

With increasing public scrutiny on animal welfare, it behooves those involved in the equine industry to revisit best management practices to ensure these support healthy horses. There is little published research on how horses are used in the equine industry, particularly in therapeutic horseback riding (THR) programs. Although there is a large amount of information on the benefits of THR programs to the participants, there is little published information available about the horses. Therefore, the objective of this survey was to gather data regarding horse use and care in Professional Association of Therapeutic Horsemanship International (PATH Intl.)–affiliated THR programs in the United States to help establish a foundation for a standard of care. A 20-question survey sent to 659 PATH Intl.–affiliated THR programs returned a 40% response rate. Demographics demonstrated that the median number of horses in each program was 10; geldings outnumbered mares; most horses were between 16 and 20 years of age; and Quarter Horse or stock-type breeds predominated. Median session length was 8 weeks and median lesson length was 45 minutes. Horses were typically ridden by clients 4 days/week and 2 hours/day. Most horses were donated to the programs, participated for approximately 7 years, and left because of aging. Limb lameness and back soreness were the top health issues noted, with only a small percentage of colic and ulcers reported. More horses received nonsteroidal anti-inflammatory drugs for a lameness issue, chiropractic adjustment, and massage than any other supplemental care or complementary therapy. Based on data gathered in this survey, THR horses were not worked excessively. Horses were ridden less than PATH Intl.’s maximum recommendation of 6 hours/day and 6 days/week and less than those used in university programs. Horses in THR programs also appeared to have fewer reported health issues as compared with data in other national reports

Optimization of a scalable single-use manufacturing platform for expansion of high quality human mesenchymal stem cells

Human mesenchymal stem cells (hMSCs) isolated from various tissues represent the most highly utilized cell type for cell therapy and regenerative medicine applications. Given that large numbers of high quality cells are required for many applications and that large surface area requirement for cell expansion is necessary, a search for a practical manufacturing platform for cell expansion has been ongoing over the last decade. Feasibility studies have demonstrated the utility of using microcarrriers in dynamic cultures for expansion of hMSCs and the results have positioned this technology as the platform of choice for the cost-effective generation of cells. Microcarrier cultures performed in fully closed single-use systems provide a cGMP-compliant platform for cell expansion and are a logical extension of traditional manufacturing technologies. However the use of high quality cell banks and bioprocess medium in these platforms significantly impacts overall performance. In addition, development of methods to reproducibly harvest and concentrate cells expanded on microcarriers in closed systems is critical. We have developed a rapid and robust manufacturing platform that enables reproducible expansion and harvest of 28 billion hMSCs from a one passage fed-batch microcarrier culture in a single use reactor seed train in only 8 days. Our system reproducibly achieves hMSC media productivity of \u3e 500M cells/L of media consumed. Data will be presented from experiments using sterile microcarriers (Pall SoloHill) in single use bioreactors (Pall Corp) with high volume hMSC seed stock and a fed-batch bioprocess medium (RoosterBio), including quality parameters related to identity flow markers, angiogenic cytokine secretion profile, multi-lineage differentiation, and inducible immunomodulatory functions. This system has the potential to be rapidly implemented at multiple sites enabling product developers to quickly produce tens of billions of high quality hMSCs for Regenerative Medicine product development programs

Estimates of parameters between direct and maternal genetic effects for weaning weight and genetic effects for carcass traits in crossbred cattle

Estimates of heritabilities and genetic correlations were obtained from weaning weight records of 23,681 crossbred steers and heifers, and carcass data of 4,094 crossbred steers using REML applied to animal models. Direct and maternal heritabilities for weaning weight were 0.14 and 0.19, respectively. The genetic correlation between direct and maternal weaning weight was negative (-0.18). Heritabilities for carcass traits of steers were moderate to large (0.34 to 0.60). Genetic correlations between direct genetic effects for weaning weight and carcass traits were small, except with hot carcass weight (0.70), ribeye area (0.29) and adjusted fat thickness (0.26). Genetic correlations of maternal genetic effects for weaning weight with direct genetic effects for carcass traits were: hot carcass weight (0.61), retail product percentage (-0.33), fat percentage (0.33), ribeye area (0.29), marbling score (0.28), and adjusted fat thickness (0.25). These results indicate that maternal genetic effects for weaning weight may be correlated with genetics for propensity to fatten in steers. Selection for only direct weaning weight would be expected to increase carcass weight and ribeye area and slightly decrease marbling and retail product percentage. Selection for either increased maternal or direct weaning weight would be expected to result in increased carcass weight, ribeye area, and fat thickness, but would not be expected to affect tenderness

EMPIRICAL ESTIMATES OF POWER FOR BINOMIAL DATA WITH MIXED MODELS

Observations on return to estrus from anestrus postpartum beef cows were used as the basis for a simulation study to develop a method to determine numbers of locations and animals per treatment per location to achieve a specified power of test. Estimates of among location and total variance were obtained by REML from the data set and then used to generate simulated data for the binomial trait. Each combination of several pre-determined factors was replicated 1000 times. Pre-determined factors were number of locations, number of animals per treatment per location, desired detectable difference due to treatment, alpha-probability level and ratio of among location to total variance. Two methods were used to test for treatment differences. In Method 1, simulated data were analyzed using a mixed model with the variance components used for the simulation based on estimates from the postpartum cow data. For Method 2, variance components were re-estimated from each replicate of the simulated data and used in the mixed model equations. The number of significant differences due to treatment was counted for the 1000 replicates. The fraction of replicates with significant differences is an empirical estimate of the power of the test. The comparison of power of test between the two methods indicates Method 2 may be preferable for empirical estimation of power of test

Collaboration Between Extension and Industry: Coordination and Assessment of Technical Large Animal Emergency Rescue Training

Rescuing large animals from emergency situations can be fraught with dangers not only to the animals but also to the rescuers. People involved at the scene of such an emergency are most likely to include first responders, horse owners, and veterinarians. These groups need to be aware of how they can best work together to effect a safe and efficient rescue as none typically has all the knowledge and skills that are necessary. Extension training programs that bring together such groups can be beneficial in supporting emergency and disaster preparedness in the local community

Estimates of parameters between direct and maternal genetic effects for weaning weight and direct genetic effects for carcass traits in crossbred cattle

Estimates of heritabilities and genetic correlations were obtained for weaning weight records of 23,681 crossbred steers and heifers and carcass records from 4,094 crossbred steers using animal models. Carcass traits included hot carcass weight; retail product percentage; fat percentage; bone percentage; ribeye area; adjusted fat thickness; marbling score, Warner- Bratzler shear force and kidney, pelvic and heart fat percentage. Weaning weight was modeled with fixed effects of age of dam, sex, breed combination, and birth year, with calendar birth day as a covariate and random direct and maternal genetic and maternal permanent environmental effects. The models for carcass traits included fixed effects of age of dam, line, and birth year, with covariates for weaning and slaughter ages and random direct and maternal effects. Direct and maternal heritabilities for weaning weight were 0.4 ± 0.02 and 0.19 ± 0.02, respectively. The estimate of direct-maternal genetic correlation for weaning weight was negative (−0.18 ± 0.08). Heritabilities for carcass traits of steers were moderate to high (0.34 to 0.60). Estimates of genetic correlations between direct genetic effects for weaning weight and carcass traits were small except with hot carcass weight (0.70), ribeye area (0.29), and adjusted fat thickness (0.26). The largest estimates of genetic correlations between maternal genetic effects for weaning weight and direct genetic effects for carcass traits were found for hot carcass weight (0.61), retail product percentage (−0.33), fat percentage (0.33), ribeye area (0.29), marbling score (0.28) and adjusted fat thickness (0.25), indicating that maternal effects for weaning weight may be correlated with genotype for propensity to fatten in steers