ASSESSING STEM LITERACY IN AN INFORMAL LEARNING ENVIRONMENT

This mixed methods study investigated methods for assessing STEM literacy amongst middle grades students participating in an informal learning environment, specifically, a summer STEM camp. Adopting a situated perspective on STEM literacy, this dissertation employed psychometric techniques and discourse analysis to answer the overarching research question: How can STEM literacy amongst middle school students be assessed in the context of a summer STEM camp? An integrated review of literacy within and across STEM disciplines first offered a new direction for conceptualizing STEM literacy. With this understanding, subsequent research methods applied novel approaches for investigating STEM literacy in the context of a summer STEM camp. Quantitatively, various measurement models were tested for reasonableness in representing pre- and post-survey data to show a two-tier bifactor solution can be used to model the chosen quantitative survey. The calibrated data was represented by four correlated primary factors (science literacy, technological literacy, mathematical literacy, and engineering literacy) and four uncorrelated specific factors, orthogonal to the primary factors. The final four specific factors were characterized by affective components related to definitions of literacy in STEM disciplines and STEM literacy more holistically including: (1) self-efficacy/perception of ability, (2) attitude and interest (willingness to engage, career belief, disposition), (3) role and utility of STEM in society, and (4) sense of community. Qualitatively, written reflection data were analyzed by first dichotomizing qualitative themes and then by using three of Gee’s inquiry tools (1999, 2005, 2011): situated meanings, social language, and Discourses; to analyze three of Gee’s building tasks of language (1999, 2005, 2011): significance, practices, and identities. Aspects of STEM literacy that involve knowledge and skills related to STEM activities were the focus of analyzing qualitative data. The findings from the discourse analysis suggest the style of language supportive of emerging STEM literacy can be understood through the context for learning; the enactment of STEM identities and STEM practices allow for this emergence as students utilize STEM language. The combination of psychometrics and discourse analysis to analyze data collected during STEM camp allowed for investigating how different research tools can offer insight into assessing different aspects of STEM literacy. This research offers applications of research methods to data collected in an informal learning environment to investigate how STEM literacy can be assessed. The overall conclusion involves the recognition of the complexity in understanding STEM literacy amongst middle school students and the need to consider knowledge, skills and dispositions when assessing STEM literacy. Possible implications of the work to assess STEM literacy in an informal context are discussed. Recommendations for designing and implementing assessment to measure STEM literacy in an informal learning environment are made. Ultimately effective consistent methods for measuring STEM literacy could shape learning opportunities for K-12 students to achieve STEM literacy as an outcome and promote equitable educational experiences for all students

Ipsilateral Lower Limb Weakness After Sarcoma Treatment: A Case Report

Case Diagnosis: Our patient experienced worsening left foot neuropathy following chemotherapy and radiation treatment for sarcoma. Case Description: A 24-year-old man underwent local resection of a 12cm x 8cm x 14.5cm rhabdomyosarcoma in the left vastus lateralis. Then, he was treated with vincristine for 40 weeks and radiation to the left lateral thigh with a maximum dose of 50.4 Gy. The sciatic nerve was outside the target area and received a lower dose. While undergoing chemotherapy, the patient experienced bilateral dysesthesias in his fingertips and feet. He had no history of neuropathy prior to treatment. After chemotherapy was completed, these symptoms subsided in all extremities except the left foot, which developed atraumatic plantar flexion and dorsiflexion weakness, great toe extensor and flexor weakness, decreased sensation in the distal left toe to the metatarsal. Electromyography and needle conduction studies demonstrated left worse than right polyneuropathy mainly affecting the tibial and peroneal motor nerves. There was no clear evidence of a single nerve compressive lesion and repeat scans of the thigh showed no new lesion. Given the presence of milder nerve abnormalities on the right in addition to left sided weakness, the cause is likely multifactorial and temporally related to cancer treatments. Discussions: Persistent or worsening features may appear in patients who received vincristine despite termination of treatment. The pattern is typically sensorimotor; however, this patient demonstrates mainly motor abnormalities. The left worse than right pattern could suggest radiation-induced neuropathy, but no myokymic potentials were seen. Myokymic potentials are common in radiation neuropathy, although their absence does not rule it out. Treatment included physical therapy, gabapentin, and an ankle foot orthosis. Conclusions: Fourteen months after completing radiation and seven months after completing chemotherapy (seven months after symptom onset), the patient’s symptoms are markedly improved. This case demonstrates that neuropathy after treatment in sarcoma patients may be multifactorial

Uplift and Seismicity driven by Magmatic Inflation at Sierra Negra Volcano, Galápagos Islands

Catalogue of detected earthquakes and cGPS uplift timeseries for Sierra Negra Volcano, Galapagos Island

Will present day glacier retreat increase volcanic activity? Stress induced by recent glacier retreat and its effect on magmatism at the Vatnajokull ice cap, Iceland

Global warming causes retreat of ice caps and ice sheets. Can melting glaciers trigger increased volcanic activity? Since 1890 the largest ice cap of Iceland, Vatnajokull, with an area of similar to 8000 km(2), has been continuously retreating losing about 10% of its mass during last century. Present-day uplift around the ice cap is as high as 25 mm/yr. We evaluate interactions between ongoing glacio-isostasy and current changes to mantle melting and crustal stresses at volcanoes underneath Vatnajokull. The modeling indicates that a substantial volume of new magma, similar to 0.014 km(3)/yr, is produced under Vatnajokull in response to current ice thinning. Ice retreat also induces significant stress changes in the elastic crust that may contribute to high seismicity, unusual focal mechanisms, and unusual magma movements in NW-Vatnajokull

Jahn-Teller stabilization of a "polar" metal oxide surface: Fe3O4(001)

Using ab initio thermodynamics we compile a phase diagram for the surface of Fe3O4(001) as a function of temperature and oxygen pressures. A hitherto ignored polar termination with octahedral iron and oxygen forming a wave-like structure along the [110]-direction is identified as the lowest energy configuration over a broad range of oxygen gas-phase conditions. This novel geometry is confirmed in a x-ray diffraction analysis. The stabilization of the Fe3O4(001)-surface goes together with dramatic changes in the electronic and magnetic properties, e.g., a halfmetal-to-metal transition.Comment: 4 pages, 4 figure

GPS constraints on deformation in northern Central America from 1999 to 2017, Part 1 – Time-dependent modelling of large regional earthquakes and their post-seismic effects

We use continuous and campaign measurements from 215 GPS sites in northern Central America and southern Mexico to estimate coseismic and afterslip solutions for the 2009 Mw = 7.3 Swan Islands fault strike-slip earthquake and the 2012 Mw = 7.3 El Salvador and Mw = 7.4 Guatemala thrust-faulting earthquakes on the Middle America trench. Our simultaneous, time-dependent inversion of more than 350 000 daily GPS site positions gives the first jointly consistent estimates of the coseismic slips for all three earthquakes, their combined time-dependent post-seismic effects and secular station velocities corrected for both the coseismic and post-seismic deformation. Our geodetic slip solutions for all three earthquakes agree with previous estimates that were derived via static coseismic-offset modelling. Our time-dependent model, which attributes all transient post-seismic deformation to earthquake afterslip, fits nearly all of the continuous GPS site position time-series within their severalmillimetre position noise. Afterslip moments for the three earthquakes range from 35 to 140 per cent of the geodetic coseismic moments, with the largest afterslip estimated for the 2012 El Salvador earthquake along the weakly coupled El Salvador trench segment. Forward modelling of viscoelastic deformation triggered by all three earthquakes for a range of assumed mantle and lower crustal viscosities suggests that it accounts for under 20 per cent of the observed post-seismic deformation and possibly under 10 per cent

Surface structure, bonding, and dynamics: The universality of zincblende (110) potential energy surfaces

Using a tight-binding, total energy (TBTE) model we examine the hypothesis that the potential energy surfaces (PES) describing the (110) cleavage faces of the tetrahedrally coordinated, zincblende-structure compound semiconductors exhibit a common universal'' form if expressed in terms of suitably scaled parameters. TBTE calculations on both III-V and II-VI compounds reveal a linear scaling with bulk lattice constant of the geometric parameters of the reconstructed surfaces. This scaling is analogous to that found using low-energy, electron-diffraction surface-structure determination. The surface atomic force constants (found from a TBTE calculation) also scale monotonically with the lattice constant. Using TBTE models proposed previously for GaP, GaAs, GaSb, InP, and ZnSe, we find that the force constants scale as the inverse square of the bulk lattice constant. These results suggest that if distances are measured in units of the bulk lattice constant, the PES may be a universal function for the cleavage surface of zincblende-structure compound semiconductors, on average, with small fluctuations from this average occurring in individual materials. 22 refs., 5 figs., 1 tab