The impact of overturning and horizontal circulation in Pine Island Trough on ice shelf melt in the eastern Amundsen Sea

The ice shelves around the Amundsen Sea are rapidly melting as a result of the circulation of relatively warm ocean water into their cavities. However, little is known about the processes that determine the variability of this circulation. Here we use an ocean circulation model to diagnose the relative importance of horizontal and vertical (overturning) circulation within Pine Island Trough, leading to Pine Island and Thwaites ice shelves. We show that melt rates and southwardCircumpolar Deep Water (CDW)transports covary over large parts of the continental shelf at interannual to decadal time scales. The dominant external forcing mechanism for this variability is Ekman pumping and suction on the continental shelf and at the shelf break, in agreementwith previous studies.At the continental shelf break, the southward transport of CDWand heat is predominantly barotropic. Farther south within Pine Island Trough, northward and southward barotropic heat transports largely cancel, and the majority of the net southward temperature transport is facilitated by baroclinic and overturning circulations. The overturning circulation is related to water mass transformation and buoyancy gain on the shelf that is primarily facilitated by freshwater input from basal melting

Achieving the Promise of Educational Opportunity: Graduate Student Debt for STEM vs. Non-STEM Students, 2012

Using NPSAS 2012 data, this study examines graduate student debt for STEM versus non-STEM students who were enrolled in a master’s or doctoral degree program in 2012. Findings showed significantly higher debt for those in non-STEM programs as well as differences by amount of undergraduate debt, race, and full- or part-time enrollment status. These differences may encourage more STEM participation, but may restrict some students from enrolling in graduate-level programs, particularly in non-STEM fields. The loss of a new generation of citizens with graduate level training may affect our national economy and productivity, and urges institution officials to consider means to offer financial aid to a larger number of graduate students

Student Loan Default: Do Characteristics of Four-Year Institutions Contribute to the Puzzle?

College student debt and loan default are growing concerns in the United States. For each U.S. institution, the federal government is now reporting a cohort default rate, which is the percent of students who defaulted on their loan, averaged over a three-year period. Previous studies have amply shown that student characteristics are strongly associated with educational debt and one’s ability to repay student loans; however, few studies have deeply examined the relationship between institutional characteristics and student loan default. This study examined characteristics of 1,399 four-year notfor-profit U.S. institutions and found significant differences in the 2010 federal student loan default rate by some important institutional variables, including admissions yield, geographic region, percent of minority students, institution control (private versus public), endowment, and expenditures for student services. Findings related to institutional characteristics can illuminate our understanding of the student loan default puzzle, and have implications for student success, academic policy, and resource allocation decisions

Participation in Undergraduate Research at Minority-Serving Institutions

This research used a national dataset to examine factors associated with participation for underrepresented minority (URM) students, benefits of participation at minority-serving institutions, and examples of programs that work to decrease barriers for URM participation in UR. Findings showed that Latino and first-generation students participated in UR less than White peers, but students at Minority Serving Institutions who participated in research with a faculty member reported using more learning strategies, increased collaboration, and having more experience with quantitative reasoning than students not participating in an UR experience

It’s Not About Charity, It’s About Justice

As we emerge from the winter and Covid-19 looks to have been tamed, the UK Government is now seeking to return to some type of “situation normal” and as such has been phasing out assistance to those affected by the Pandemic. However, the prospect emerges of life getting more difficult for the majority of us. In this context, the spectacle of a beleaguered and mendacious Prime Minister and his entourage being subject to a police investigation in allegedly having violated their own rules on Covid-19 restrictions is a mere side-show

Garnet as Indicator of Pegmatite Evolution: The Case Study of Pegmatites from the Oxford Pegmatite Field (Maine, USA)

Almandine-spessartine garnets, from the Oxford County pegmatites and the Palermo No. 1 pegmatite, record significant compositional variations according to the degree of evolution of their hosting rock. Garnets from the most fractionated pegmatites (Mt. Mica, Berry-Havey, and Emmons) show the highest Mn, Nb, Ta, Zr, and Hf values, followed by those from the intermediate grade pegmatites (Palermo No. 1) and, finally, garnets from the barren pegmatites show the lowest values (Perham and Stop-35). Iron, Ca, and Mg contents follow an inverse order, with the highest contents in the latter pegmatites. Major element zoning shows increasing Mn values from core to rim in most garnet samples, while trace element zoning is not systematic except for some crystals which show a core to rim depletion for most of these elements. Chondrite normalized HREE (Heavy Rare Earth Elements) spectra show positive slopes for garnets from barren pegmatites, both positive and negative slopes for those associated with the intermediate pegmatite, and negative or flat slopes in garnets from the highly fractionated pegmatites. Ion exchange mechanisms, including Fe2+−1Mn2+1, (Fe2+, Mn2+)−1Si−1Li1P1; and, (Y, Ho3+)2(vac)1(Fe2+, Mn2+)−3, could explain most of the compositional variations observed in these garnets. These compositional variations are the reflection of the composition of the pegmatitic magma (barren pegmatites originate from a more ferromagnesian magma than fractionated pegmatites); and of the coexisting mineral phases competing with garnets to host certain chemical elements, such as biotite, schorl, plagioclase, apatite, Fe-Mn phosphates, Nb-Ta oxides, zircon, xenotime, and monazite.This research was funded by the Spanish Ministry of Economy, Industry and Competitiveness (project no. RTI2018‐094097‐B‐100, with ERDF funds), the University of the Basque Country UPV/EHU (grant no. GIU18/084) and the European Union’s Horizon 2020 Innovation Programme (grant agreement no. 869274, project GREENPEG: New Exploration Tools for European Pegmatite Green‐Tech Resources). Maine Mineral and Gem Museum (USA) also contributed economically

Garnet as Indicator of Pegmatite Evolution: The Case Study of Pegmatites from the Oxford Pegmatite Field (Maine, USA)

Almandine-spessartine garnets, from the Oxford County pegmatites and the Palermo No. 1 pegmatite, record significant compositional variations according to the degree of evolution of their hosting rock. Garnets from the most fractionated pegmatites (Mt. Mica, Berry-Havey, and Emmons) show the highest Mn, Nb, Ta, Zr, and Hf values, followed by those from the intermediate grade pegmatites (Palermo No. 1) and, finally, garnets from the barren pegmatites show the lowest values (Perham and Stop-35). Iron, Ca, and Mg contents follow an inverse order, with the highest contents in the latter pegmatites. Major element zoning shows increasing Mn values from core to rim in most garnet samples, while trace element zoning is not systematic except for some crystals which show a core to rim depletion for most of these elements. Chondrite normalized HREE (Heavy Rare Earth Elements) spectra show positive slopes for garnets from barren pegmatites, both positive and negative slopes for those associated with the intermediate pegmatite, and negative or flat slopes in garnets from the highly fractionated pegmatites. Ion exchange mechanisms, including Fe2+−1Mn2+1, (Fe2+, Mn2+)−1Si−1Li1P1; and, (Y, Ho3+)2(vac)1(Fe2+, Mn2+)−3, could explain most of the compositional variations observed in these garnets. These compositional variations are the reflection of the composition of the pegmatitic magma (barren pegmatites originate from a more ferromagnesian magma than fractionated pegmatites); and of the coexisting mineral phases competing with garnets to host certain chemical elements, such as biotite, schorl, plagioclase, apatite, Fe-Mn phosphates, Nb-Ta oxides, zircon, xenotime, and monazite.This research was funded by the Spanish Ministry of Economy, Industry and Competitiveness (project no. RTI2018-094097-B-100, with ERDF funds), the University of the Basque Country UPV/EHU (grant no. GIU18/084) and the European Union’s Horizon 2020 Innovation Programme (grant agreement no. 869274, project GREENPEG: New Exploration Tools for European Pegmatite Green-Tech Resources). Maine Mineral and Gem Museum (USA) also contributed economically

Institutional research in South African higher education: Framing the contexts and practices

CITATION: Botha, J., Muller, N. J. & Webber, K. 2016. Institutional Research in South African Higher Education: Framing the Contexts and Practices, in J. Botha & N. J. Muller (eds.). Institutional Research in South African Higher Education: Intersecting Contexts and Practices. Stellenboach: SUN PRESS. 1-22. doi:10.18820/9781928357186/01.The original publication is available from AFRICAN SUNMeDIA.Universities are among the oldest social organisations in the world. Few would doubt that universities are crucially important social organisations. The public and private good of universities is generally recognised (and widely debated, cf. Singh 2001). The broad range of purposes ascribed to universities and society’s expectations of the value added by universities add up to form an intriguing phenomenon which is the object of research in a range of academic disciplines and professional practices.Publishers' versio

Winter seal-based observations reveal glacial meltwater surfacing in the southeastern Amundsen Sea

Funding: This work is funded by the UK Natural Environment Research Council under the iSTAR Programme through grants NE/J005703/1 (K.J.H., D.P.S., B.G.M.W.); European Research Council (under H2020-EU.1.1.) under research grant COMPASS (Climate-relevant Ocean Measurements and Processes on the Antarctic continental Shelf and Slope, grant agreement ID: 741120, K.J.H., Y.Z.); National Science Foundation Division of Polar Programs and Natural Environment Research Council under the research grant TARSAN (Thwaites-Amundsen Regional Survey and Network, NSF PLR 1738992 and NE/S006419/1, K.J.H.).Y.Z. is supported by China Scholarship Council and University of East Anglia. L.C.B. is supported by a Wallenberg Academy Fellowship (WAF 2015.0186) and Swedish Research Council grant (VR2019-04400) of S. Swart.Determining the injection of glacial meltwater into the polar oceans is crucial for quantifying the response of the climate system to ice sheet mass loss. However, meltwater is poorly observed and its pathways poorly known, especially in winter. Here we present winter meltwater distribution in the eastern Amundsen Sea near Pine Island Glacier, revealing a highly variable meltwater distribution with two meltwater-rich layers in the upper 250 m and at around 450 m, connected by scattered meltwater-rich columns. We show that the hydrographic signature of meltwater is clearest in winter, when its presence can be unambiguously mapped throughout the water column. We argue that the buoyant meltwater provides near-surface nutrient that enhances productivity and heat that helps maintain polynyas, close to ice shelves across the Amundsen Sea. Therefore, although the processes determining the distribution of meltwater are challenging, they are important to represent in Earth system models.Publisher PDFPeer reviewe

A1: Lithium-Boron-Beryllium Gem Pegmatites, Oxford Co., Maine: Havey and Mount Mica Pegmatites

Guidebook for field trips in Western Maine and Northern New Hampshire: New England Intercollegiate Geological Conference, p. 1-34