Assessment of the Repeated Speech Performance as a Pedagogical Tool: A Pilot Study

Realizing the ongoing need to develop pedagogy in public speaking, these researchers investigated the learning achieved by asking students to repeat one of their speech assignments. They assessed the value of this practice from the students\u27 viewpoint as well as the statistical change in performance outcomes. Across the eight competencies evaluated, students\u27 average scores increased significantly on the repeated speech. Students who scored in the lower quartile on the first speech benefited most from the second opportunity. The researchers conclude that allowing students to repeat a speech appears to have pedagogical and practical merit

Writing Rock Stars: An After-School Community Partnership in Childhood Literacy

This study explains the development, implementation, and preliminary findings of an after-school pilot writing program that drew upon a peer collaborative model and a community literacy perspective. Preliminary findings suggest important benefits of this partnership for young children, parents, and the surrounding community

Temperature effects on metabolic scaling of a keystone freshwater crustacean depend on fish-predation regime.

According to the metabolic theory of ecology, metabolic rate, an important indicator of the pace of life, varies with body mass and temperature due to internal physical constraints. However, various ecological factors may also affect metabolic rate and its scaling with body mass. Although reports of such effects on metabolic scaling usually focus on single factors, the possibility of significant interactive effects between multiple factors requires further study. In this study, we show that the effect of temperature on the ontogenetic scaling of resting metabolic rate of the freshwater amphipod Gammarus minus depends critically on habitat differences in predation regime. Increasing temperature tends to cause decreases in the metabolic scaling exponent (slope) in population samples from springs with fish predators, but increases in population samples from springs without fish. Accordingly, the temperature sensitivity of metabolic rate is not only size-specific, but also its relationship to body size shifts dramatically in response to fish predators. We hypothesize that the dampened effect of temperature on the metabolic rate of large adults in springs with fish, and of small juveniles in springs without fish are adaptive evolutionary responses to differences in the relative mortality risk of adults and juveniles in springs with versus without fish predators. Our results demonstrate a complex interaction among metabolic rate, body size, temperature, and predation regime. The intraspecific scaling of metabolic rate with body size and temperature is not merely the result of physical constraints related to internal body design and biochemical kinetics, but rather is ecologically sensitive and evolutionarily malleable

Juvenile crappie growth and bioenergetics: implications for management using blacknose crappie

Collectively, black crappie Pomoxis nigromaculatus and white crappie P. annularis make up important harvest-oriented sport fisheries across North America, especially in the Midwest. Over the past several decades, the major management issues facing crappie populations have been identified as poor size structure and highly variable recruitment. Although stocking programs have not been historically common for crappie, some recent examples have been successful in supplementing year classes in systems with poor recruitment. In order to differentiate stocked from naturally occurring individuals for evaluations of stocking programs, several management agencies have cultured and stocked blacknose crappie, a phenotypic variant of black crappie. Continued use of blacknose crappie by managers has also stemmed from perceived differences in growth and survival relative to black crappie in rearing environments. My thesis evaluates growth-related differences among juvenile black, white, and blacknose crappies in both experimental ponds and the laboratory. In a common garden pond experiment, I found no differences in survival among strains or ponds. Blacknose crappie outgrew black and white crappies in both length and weight and black crappie outgrew white crappie in just weight. Growth was pond-dependent for all strains, with growth rates being highest in ponds with high zooplankton density, low macroinvertebrate density, and low vegetation density. Turbidity also may have had indirect effects on the growth of black and blacknose crappies, but not white crappie. Across a range of temperatures in the laboratory, I found no differences in metabolic rate among the strains. I also observed superior growth characteristics of blacknose crappie in the laboratory, as they exhibited higher relative growth rates and food conversion efficiencies than black and white crappies. Black and blacknose crappies also had higher maximum food consumption rates than white crappie. No strain-temperature interactions were detected for the suite of parameters measured, suggesting a lack of differential thermal adaptations among black, white, and blacknose crappies. Differences in growth and food conversion efficiency between blacknose and black crappies may be attributable to selective pressures associated with the multi-decadal culture of the strain, especially in a species where survival and handling mortality are highly size-dependent. My laboratory results indicated ontogenetic shifts in thermal optima for juvenile crappies when compared to previous studies with adult white crappie. Results of my thesis can improve future juvenile crappie bioenergetics models and advise management decisions using blacknose crappie. Blacknose crappie may provide a better alternative to other crappies for stocking programs, but potential negative impacts on resident crappie populations need to be investigated in the future due to the origin of the strain coming from a single source population. Blacknose crappie exhibit superior growth characteristics over black and white crappies in rearing environments and these relationships should be evaluated further at larger spatial scales and across varying environmental conditions

Quantum dynamics of impurities in a 1D Bose gas

Using a species-selective dipole potential, we create initially localized impurities and investigate their interactions with a majority species of bosonic atoms in a one-dimensional configuration during expansion. We find an interaction-dependent amplitude reduction of the oscillation of the impurities' size with no measurable frequency shift, and study it as a function of the interaction strength. We discuss possible theoretical interpretations of the data. We compare, in particular, with a polaronic mass shift model derived following Feynman variational approach.Comment: 7 pages, 6 figure

Efficiency bounds for nonequilibrium heat engines

We analyze the efficiency of thermal engines (either quantum or classical) working with a single heat reservoir like atmosphere. The engine first gets an energy intake, which can be done in arbitrary non-equilibrium way e.g. combustion of fuel. Then the engine performs the work and returns to the initial state. We distinguish two general classes of engines where the working body first equilibrates within itself and then performs the work (ergodic engine) or when it performs the work before equilibrating (non-ergodic engine). We show that in both cases the second law of thermodynamics limits their efficiency. For ergodic engines we find a rigorous upper bound for the efficiency, which is strictly smaller than the equivalent Carnot efficiency. I.e. the Carnot efficiency can be never achieved in single reservoir heat engines. For non-ergodic engines the efficiency can be higher and can exceed the equilibrium Carnot bound. By extending the fundamental thermodynamic relation to nonequilibrium processes, we find a rigorous thermodynamic bound for the efficiency of both ergodic and non-ergodic engines and show that it is given by the relative entropy of the non-equilibrium and initial equilibrium distributions.These results suggest a new general strategy for designing more efficient engines. We illustrate our ideas by using simple examples.Comment: updated version, 16 pages, 3 figure