A comparison of the performance of developmental students with regular students in a college-level mathematics course.

The purpose of this study was to compare the performance of developmental students and regular students in a college-level mathematics course at a comprehensive community college. In this study, students were identified as developmental students if they were required to complete a developmental algebra course. Regular students were those students who were not required to complete this developmental algebra course based on their mathematics section ACT score or their ASSET elementary algebra score. The hypotheses were concerned with identifying any significant differences in the performance of the developmental students as compared to the performance of the regular students in a college-level mathematics course. The dependent variables were the score on a comprehensive final examination, course grade point average (quality points) and the percentage of passing grades (D or better). Data for the mean score on the comprehensive final examination was obtained from students\u27 scores. Data for the mean course grade point average and the percentage of passing grades was extracted from faculty grade reports. The results of the study showed that developmental students achieved a lower, but not significantly lower, mean score on the comprehensive final examination and on the mean course grade point average. There was no significant difference in the percentage of passing grades between the two groups. Other independent variables reported on in the study were age, gender, and meeting time (day or evening) of the college-level mathematics course. Students above age 37 achieved a significantly higher mean course grade point average than students under age 23. Female students achieved a higher mean score on the comprehensive final examination and a significantly higher mean course grade point average and percentage of passing grades. Students enrolled in the day sections of the course achieved a significantly higher mean score on the comprehensive final examination. Based on the findings of this study, there was no significant difference in the performance of the developmental students when compared to the performance of the regular students

How fast is fast? Eco-evolutionary dynamics and rates of change in populations and phenotypes

It is increasingly recognized that evolution may occur in ecological time. It is not clear, however, how fast evolution – or phenotypic change more generally – may be in comparison with the associated ecology, or whether systems with fast ecological dynamics generally have relatively fast rates of phenotypic change. We developed a new dataset on standardized rates of change in population size and phenotypic traits for a wide range of species and taxonomic groups. We show that rates of change in phenotypes are generally no more than 2/3, and on average about 1/4, the concurrent rates of change in population size. There was no relationship between rates of population change and rates of phenotypic change across systems. We also found that the variance of both phenotypic and ecological rates increased with the mean across studies following a power law with an exponent of two, while temporal variation in phenotypic rates was lower than in ecological rates. Our results are consistent with the view that ecology and evolution may occur at similar time scales, but clarify that only rarely do populations change as fast in traits as they do in abundance

How fast is fast? Eco-evolutionary dynamics and rates of change in populations and phenotypes

It is increasingly recognized that evolution may occur in ecological time. It is not clear, however, how fast evolution – or phenotypic change more generally – may be in comparison with the associated ecology, or whether systems with fast ecological dynamics generally have relatively fast rates of phenotypic change. We developed a new dataset on standardized rates of change in population size and phenotypic traits for a wide range of species and taxonomic groups. We show that rates of change in phenotypes are generally no more than 2/3, and on average about 1/4, the concurrent rates of change in population size. There was no relationship between rates of population change and rates of phenotypic change across systems. We also found that the variance of both phenotypic and ecological rates increased with the mean across studies following a power law with an exponent of two, while temporal variation in phenotypic rates was lower than in ecological rates. Our results are consistent with the view that ecology and evolution may occur at similar time scales, but clarify that only rarely do populations change as fast in traits as they do in abundance

\u3ci\u3eStaphylococcus aureus\u3c/i\u3e Metabolic Adaptations during the Transition from a Daptomycin Susceptibility Phenotype to a Daptomycin Nonsusceptibility Phenotype

Staphylococcus aureus is a major cause of nosocomial and community-acquired infections. The success of S. aureus as a pathogen is due in part to its many virulence determinants and resistance to antimicrobials. In particular, methicillin-resistant S. aureus has emerged as a major cause of infections and led to increased use of the antibiotics vancomycin and daptomycin, which has increased the isolation of vancomycin-intermediate S. aureus and daptomycin-nonsusceptible S. aureus strains. The most common mechanism by which S. aureus acquires intermediate resistance to antibiotics is by adapting its physiology and metabolism to permit growth in the presence of these antibiotics, a process known as adaptive resistance. To better understand the physiological and metabolic changes associated with adaptive resistance, six daptomycin-susceptible and -nonsusceptible isogenic strain pairs were examined for changes in growth, competitive fitness, and metabolic alterations. Interestingly, daptomycin nonsusceptibility coincides with a slightly delayed transition to the postexponential growth phase and alterations in metabolism. Specifically, daptomycin-nonsusceptible strains have decreased tricarboxylic acid cycle activity, which correlates with increased synthesis of pyrimidines and purines and increased carbon flow to pathways associated with wall teichoic acid and peptidoglycan biosynthesis. Importantly, these data provided an opportunity to alter the daptomycin nonsusceptibility phenotype by manipulating bacterial metabolism, a first step in developing compounds that target metabolic pathways that can be used in combination with daptomycin to reduce treatment failures

The Determination of the Quantity of Sulfur in Rain Water and Soils of Indiana and the Study of the Effect of Sulfur Oxidation on the Release of Soluble Manganese

Abstract not availabl

Dahlias : wholesale price list , spring 1928 /

192

Dahlias catalog and price list for 1928 sent from California to everywhere /

192

Dahlias : wholesale price list 1927 /

192