Developing Civic-Mindedness in Middle- and High-School Students Using Service-Learning

Education is not only about teaching students in academic domains, but also teaching them about the application of those domains in society as civic-minded, engaged citizens. Service learning projects can be effective at fostering a sense of civic-mindedness in students, at least in college (e.g., Weber & Weber, 2010). During the 2017-2018 school year, we conducted a case study with 73 middle school students from two rural schools in the Arkansas Delta to examine, in part, the impact of one service-learning initiative (EAST). Participating students researched authentic problems in their communities and developed projects aimed at addressing those problems. Based on data from the case study, students appeared to become more aware of problems in their communities and believed they could help to solve those problems. Using the EAST model, this proposed session will examine how service-learning projects can help secondary educators develop civic-mindedness in students

Schematic Knowledge and Memory in Preschoolers.

It has been proposed that variation in domain-specific knowledge can explain both individual and developmental differences in early memory development. The purpose of the present study is to test the hypothesized relation between knowledge and memory in 3- and 4-year-old children. In particular, this study focuses on schematic knowledge, or knowledge about objects within settings. Schematic knowledge includes information about what objects belong in settings and where they are usually located. Two scenes, a living room and farm, were created to measure children's knowledge of each of these components. Two memory tasks were also devised to measure (a) recall of the specific objects in scenes and (b) reconstruction of the locations of objects. Children's general memory skills were assessed in list-learning tasks for recall and location memory, and their general knowledge was measured with the Peabody Picture Vocabulary Test. The results indicated that the relation between knowledge and memory varied with age. Although the two cognitive abilities were unrelated for 3-year-olds, schematic knowledge and memory were correlated significantly for 4-year-olds. This pattern was observed for both scenes. Further, list-learning was correlated with different aspects of scene memory for each age group. It correlated with location memory for the 3-year-olds and recall for the 4-year-olds. Vocabulary scores were related to scene knowledge, but not to scene memory, and did not affect the relation between scene knowledge and memory. These results suggest that domain-specific knowledge may be differentially related to memory as a function of age, and that other factors, such as memory skill, may also be influencing performance, so that the relative importance of factors may vary with age. Additional analyses examined the effects of item characteristics--typicality and size--on memory, and revealed that size, but not typicality, was a strong predictor of what objects would be remembered (in recall and location-memory tasks) by the children.Ph.D.Developmental psychologyUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/161313/1/8702823.pd

Schematic Knowledge and Memory in Preschoolers

PHDPsychologyUniversity of Michiganhttps://deepblue.lib.umich.edu/bitstream/2027.42/150919/1/psychdiss011.pd

Controls on suppression of methane flux from a peat bog subjected to simulated acid rain sulfate deposition

The effect of acid rain SO42− deposition on peatland CH4 emissions was examined by manipulating SO42− inputs to a pristine raised peat bog in northern Scotland. Weekly pulses of dissolved Na2SO4 were applied to the bog over two years in doses of 25, 50, and 100 kg S ha−1 yr−1, reflecting the range of pollutant S deposition loads experienced in acid rain-impacted regions of the world. CH4 fluxes were measured at regular intervals using a static chamber/gas chromatographic flame ionization detector method. Total emissions of CH4 were reduced by between 21 and 42% relative to controls, although no significant differences were observed between treatments. Estimated total annual fluxes during the second year of the experiment were 16.6 g m−2 from the controls and (in order of increasing SO42− dose size) 10.7, 13.2, and 9.8 g m−2 from the three SO42− treatments, respectively. The relative extent of CH4 flux suppression varied with changes in both peat temperature and peat water table with the largest suppression during cool periods and episodes of falling water table. Our findings suggest that low doses of SO42− at deposition rates commonly experienced in areas impacted by acid rain, may significantly affect CH4 emissions from wetlands in affected areas. We propose that SO42− from acid rain can stimulate sulfate-reducing bacteria into a population capable of outcompeting methanogens for substrates. We further propose that this microbially mediated interaction may have a significant current and future effect on the contribution of northern peatlands to the global methane budget

Catalysis and pH Control by Membrane-associated Carbonic Anhydrase IX in MDA-MB-231 Breast Cancer Cells*

Carbonic anhydrase IX (CAIX) is a membrane-bound, tumor-related enzyme whose expression is often considered a marker for hypoxia, an indicator of poor prognosis in the majority of cancer patients, and is associated with acidification of the tumor microenvironment. Here, we describe for the first time the catalytic properties of native CAIX in MDA-MB-231 breast cancer cells that exhibit hypoxia-inducible CAIX expression. Using 18O exchange measured by membrane inlet mass spectrometry, we determined catalytic activity in membrane ghosts and intact cells. Exofacial carbonic anhydrase activity increases with exposure to hypoxia, an activity which is suppressed by impermeant sulfonamide CA inhibitors. Inhibition by sulfonamide inhibitors is not sensitive to reoxygenation. CAIX activity in intact cells increases in response to reduced pH. Data from membrane ghosts show that the increase in activity at reduced pH is largely due to an increase in the dehydration reaction. In addition, the kinetic constants of CAIX in membrane ghosts are very similar to our previous measurements for purified, recombinant, truncated forms. Hence, the activity of CAIX is not affected by the proteoglycan extension or membrane environment. These activities were measured at a total concentration for all CO2 species at 25 mm and close to chemical equilibrium, conditions which approximate the physiological extracellular environment. Our data suggest that CAIX is particularly well suited to maintain the extracellular pH at a value that favors the survival fitness of tumor cells