A new species of Goniobasis

http://deepblue.lib.umich.edu/bitstream/2027.42/56517/1/OP078.pd

The Non-Conservative Behavior of Organic Alkalinity in Simulated Gulf of Maine Estuary Mixing

Estuaries are essential coastal ecosystems facing the threat of coastal acidification due tothe anthropogenic burning of fossil fuels and eutrophication. Total alkalinity is a measure of the buffering capacity in an ecosystem and is commonly comprised of both inorganic and organic species. While the contribution of inorganic species to the total alkalinity of an ecosystem is well understood, the contribution of organic alkalinity has been understudied. This investigation looked to outline the behavior of organic alkalinity during estuary mixing and identify organic pKas through Gran + Whole titrations. Freshwater endmember samples were collected from 8 estuaries of the Gulf of Maine, spanning from Maine, U.S.A to New Brunswick, Canada, in October of 2019. The endmember samples were serially diluted with certified reference material to simulate estuary mixing. The results of this investigation highlighted the non-conservative mixing behavior of organic alkalinity with increasing salinity. An extreme variability of organic alkalinity was documented in the low salinity region of estuary mixing and may be due to colloid particle and organic acid interactions. Varying organic alkalinity equivalence point calculations yielded evidence of the presence of organic species with low pKas that must be accounted for in organic and total alkalinity calculations. To better include these low pH pKa species in different estuary environments, the 4.5 equivalence point definition commonly used during titrations for determining alkalinity needs to be re-evaluated. These findings improve the understanding of organic alkalinity behavior during estuary mixing and its contribution to the total alkalinity of the system. Without this inclusion of organic alkalinity in total alkalinity determinations, the use of carbonate system models will experience bias in predicting the resilience of estuaries to future coastal acidification

Alien Registration- Hinckley, Harriett A. (Gardiner, Kennebec County)

https://digitalmaine.com/alien_docs/29078/thumbnail.jp

Cognitive Dissonance at Dartmouth College: Measuring Student’s Openness to Politically Incongruent Ideas

Do the psychological theories of cognitive dissonance and selective exposure have bearing on how students at Dartmouth engage with news? Are students less likely to consume politically charged materials that they disagree with? Results from a true randomized survey administered to all undergraduates at the College in the classes of 2017 and 2018 found that Democrats at Dartmouth are less likely to engage with news that contradicts their political beliefs at a statistically significant level. Republicans, however, were more likely to engage with politically disagreeable news, but not at a statistically significant level

Broadening Participation in Research Focused, Upper-Division Learning Communities

We address several challenges faced by those who wish to increase the number of faculty participating in upper-division learning communities that feature a student research experience. Using illustrations from our own learning community, we describe three strategies for success that focus on providing low cost incentives and other means to promote and sustain faculty cooperation

Blue Hill, Maine. Reunion Song.

https://digitalcommons.library.umaine.edu/mmb-me/1503/thumbnail.jp

Soil-water dynamics and unsaturated storage during snowmelt following wildfire

Many forested watersheds with a substantial fraction of precipitation delivered as snow have the potential for landscape disturbance by wildfire. Little is known about the immediate effects of wildfire on snowmelt and near-surface hydrologic responses, including soil-water storage. Montane systems at the rain-snow transition have soil-water dynamics that are further complicated during the snowmelt period by strong aspect controls on snowmelt and soil thawing. Here we present data from field measurements of snow hydrology and subsurface hydrologic and temperature responses during the first winter and spring after the September 2010 Fourmile Canyon Fire in Colorado, USA. Our observations of soil-water content and soil temperature show sharp contrasts in hydrologic and thermal conditions between north- and south-facing slopes. South-facing burned soils were ∼1–2 °C warmer on average than north-facing burned soils and ∼1.5 °C warmer than south-facing unburned soils, which affected soil thawing during the snowmelt period. Soil-water dynamics also differed by aspect: in response to soil thawing, soil-water content increased approximately one month earlier on south-facing burned slopes than on north-facing burned slopes. While aspect and wildfire affect soil-water dynamics during snowmelt, soil-water storage at the end of the snowmelt period reached the value at field capacity for each plot, suggesting that post-snowmelt unsaturated storage was not substantially influenced by aspect in wildfire-affected areas. Our data and analysis indicate that the amount of snowmelt-driven groundwater recharge may be larger in wildfire-impacted areas, especially on south-facing slopes, because of earlier soil thaw and longer durations of soil-water contents above field capacity in those areas