The Cultural Studies of Science Education

In an age of accountability, the demands and constraints placed on science teachers seem insurmountable. Teachers are challenged to provide students with authentic scientific experiences, yet the need to prepare students for high-stakes tests remains. The problem of attrition and job stress in the field of science teaching is growing. As pressures rise, it becomes necessary to understand what the culture of science education is like from the perspective of the science teacher. This study sought to define the culture of science education and determine how this culture informs teacher practice in the secondary science classroom. This qualitative case study was conducted within the context of a small, rural high school with four science teachers. Data was collected through a number of procedures that included participant observation, field notes, interviews, informal conversations, focus group interviews, audio recordings, and artifacts from the school. Data analysis was conducted using inductive coding processes and grounded theory. This study found that the culture of science education was defined by the constant collaborative nature of the community of practice, the formation and negotiation of teacher identity, and policies mandated by both state and local school administration. These aspects of the culture informed teacher practice through the method of instruction used in the classroom and the depth of inquiry allowed for laboratory work

Complexity in Overmarsh Circulation

Overmarsh circulation is highly complex with variations in current direction over very short timescales and flowpaths that differ substantially between flood and ebb cycles. Understanding such flow complexities in salt marshes is important because they inherently impact the distribution of sediment, larvae and nutrients throughout the marsh, and hence, the ecogeomorphic feedbacks that control landscape evolution. The purpose this Ph.D. research is to quantitatively evaluate the effects of salt marsh topography on overmarsh circulation in a Georgia salt marsh. This dissertation is comprised of three parts. First, digital elevation models (DEMs) were compared to characterize how well airborne lidar (light detection and ranging) data depict the microtopography of a salt marsh. 72,000 GPS points and 700,000 lidar points from a 1km2 salt marsh island were linearly interpolated using identical DEM configurations. 1D comparison between the two surfaces indicates that lidar is a robust tool for mapping intertidal landscapes. However, in a 2D or 3D sense, lidar DEMs do not adequately resolve the microtopographic variations of a salt marsh, and for research questions that require accurate depiction of small scale tidal creek networks and subtle terrain features lidar data should be augmented with other information. Therefore, in the second part of this work we apply a high resolution, high precision GPS DEM to numerical simulations in Delft3D to characterize complexity in overmarsh circulation over a 1.4km2 salt marsh basin. The model results provide a robust representation of field conditions and reveal that at times not necessarily linked to the transition between flood and ebb, the current magnitude and direction were highly dynamic, with variations occurring on the order of tens of minutes. Model results show simultaneous flow divergence and convergence, concentrated flow, as well as large-scale rotational flow. Also, all spatial scales show strong differences between flood and ebb pathways, which gives rise to 53% transport of the dye export via overmarsh and intertidal creek flows, and 32% exiting through the central subtidal channel system; 15% remained in the system after five days. The complexity in overmarsh circulation arises from the submergence and emergence of salt marsh topography. In the final part of this work I systematically smooth the high resolution GPS DEM to answer the question: How much topographic detail is needed to accurately simulate overmarsh circulation? Topographic smoothing progressively reduced the basin drainage density by 97%, and in the course of averaging removed small scale intertidal creeks and creek networks. Nevertheless, simulation results show nominal effects up to a 50m x 50m grid smoothing whereupon a system-wide change from ebb to flood dominance occurs. Moreover, assessments of dye circulation reveal that tracer residence time appears to be set by the geomorphic structure of the basin. Overall, smoothing out small scale intertidal creeks and creek networks reveals their minor role in overmarsh circulation, while excessive smoothing caused the system to change from ebb to flood dominance

What does airborne LiDAR really measure in upland ecosystems?

Copyright © 2014 John Wiley & Sons, Ltd.Airborne laser scanning systems (Light Detection And Ranging, LiDAR) are very well suited to the study of landscape and vegetation structure over large extents. Spatially distributed measurements describing the three-dimensional character of landscape surfaces and vegetation architecture can be used to understand eco-geomorphic and ecohydrological processes, and this is particularly pertinent in peatlands given the increasing recognition that these landscapes provide a variety of ecosystem services (water provision, flood mitigation and carbon sequestration). In using LiDAR data for monitoring peatlands, it is important to understand how well peatland surface structures (with fine length scales) can be described. Our approach integrates two laser scanning technologies, namely terrestrial laser scanning (TLS) and airborne LiDAR surveys, to assess how effective airborne LiDAR is at measuring these fine-scale microtopographic ecohydrological structures. By combining airborne and TLS, we demonstrate an improved spatial understanding of the signal measured by the airborne LiDAR. Critically, results demonstrate that LiDAR digital surface models are subject to specific errors related to short-sward ecosystem structure, causing the vegetation canopy height and surface-drainage network depth to be underestimated. TLS is shown to be effective at describing these structures over small extents, allowing the information content and accuracy of airborne LiDAR to be understood and quantified more appropriately. These findings have important implications for the appropriate degree of confidence ecohydrologists can apply to such data when using them as a surrogate for field measurements. They also illustrate the need to couple LiDAR data with ground validation data in order to improve assessment of ecohydrological function in such landscapes. © 2014 John Wiley & Sons, Ltd.South West Water LtdUniversity of Exete

Differential Trafficking of Oxidized LDL and Oxidized LDL Immune Complexes in Macrophages: Impact on Oxidative Stress

Oxidized low-density lipoproteins (oxLDL) and oxLDL-containing immune complexes (oxLDL-IC) contribute to formation of lipid-laden macrophages (foam cells). It has been shown that oxLDL-IC are considerably more efficient than oxLDL in induction of foam cell formation, inflammatory cytokines secretion, and cell survival promotion. Whereas oxLDL is taken up by several scavenger receptors, oxLDL-IC are predominantly internalized through the FCgamma receptor I (FCgamma RI). This study examined differences in intracellular trafficking of lipid and apolipoprotein moieties of oxLDL and oxLDL-IC and the impact on oxidative stress.Fluorescently labeled lipid and protein moieties of oxLDL co-localized within endosomal and lysosomal compartments in U937 human monocytic cells. In contrast, the lipid moiety of oxLDL-IC was detected in the endosomal compartment, whereas its apolipoprotein moiety advanced to the lysosomal compartment. Cells treated with oxLDL-IC prior to oxLDL demonstrated co-localization of internalized lipid moieties from both oxLDL and oxLDL-IC in the endosomal compartment. This sequential treatment likely inhibited oxLDL lipid moieties from trafficking to the lysosomal compartment. In RAW 264.7 macrophages, oxLDL-IC but not oxLDL induced GFP-tagged heat shock protein 70 (HSP70) and HSP70B', which co-localized with the lipid moiety of oxLDL-IC in the endosomal compartment. This suggests that HSP70 family members might prevent the degradation of the internalized lipid moiety of oxLDL-IC by delaying its advancement to the lysosome. The data also showed that mitochondrial membrane potential was decreased and generation of reactive oxygen and nitrogen species was increased in U937 cell treated with oxLDL compared to oxLDL-IC.Findings suggest that lipid and apolipoprotein moieties of oxLDL-IC traffic to separate cellular compartments, and that HSP70/70B' might sequester the lipid moiety of oxLDL-IC in the endosomal compartment. This mechanism could ultimately influence macrophage function and survival. Furthermore, oxLDL-IC might regulate the intracellular trafficking of free oxLDL possibly through the induction of HSP70/70B'

A national-scale model of linear features improves predictions of farmland biodiversity

© 2017 The Authors. Journal of Applied Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society. Modelling species distribution and abundance is important for many conservation applications, but it is typically performed using relatively coarse-scale environmental variables such as the area of broad land-cover types. Fine-scale environmental data capturing the most biologically relevant variables have the potential to improve these models. For example, field studies have demonstrated the importance of linear features, such as hedgerows, for multiple taxa, but the absence of large-scale datasets of their extent prevents their inclusion in large-scale modelling studies. We assessed whether a novel spatial dataset mapping linear and woody-linear features across the UK improves the performance of abundance models of 18 bird and 24 butterfly species across 3723 and 1547 UK monitoring sites, respectively. Although improvements in explanatory power were small, the inclusion of linear features data significantly improved model predictive performance for many species. For some species, the importance of linear features depended on landscape context, with greater importance in agricultural areas. Synthesis and applications. This study demonstrates that a national-scale model of the extent and distribution of linear features improves predictions of farmland biodiversity. The ability to model spatial variability in the role of linear features such as hedgerows will be important in targeting agri-environment schemes to maximally deliver biodiversity benefits. Although this study focuses on farmland, data on the extent of different linear features are likely to improve species distribution and abundance models in a wide range of systems and also can potentially be used to assess habitat connectivity

High platform elevations highlight the role of storms and spring tides in salt marsh evolution

We combine sea level records and repeat lidar surveys at 8 sites in the United Kingdom and the United States to explore controls on marsh accretion. We compare marsh elevations relative to sea level as well as lidar-derived marsh accretion rates to simple 0-dimensional settling simulations in order to explore constraints on suspended sediment concentration and particle size. We find that the marsh platforms examined occupy a narrow range of elevations in the upper tidal frame, situated between Mean High Tide MHT and the Observed Highest High Tide OHHT. Under sinusoidal tidal forcing, common in marsh accretion models, marshes at these elevations are never inundated, highlighting the inadequacy of sinusoidal forcing in numerical models of salt marshes. Forcing the model with year-long tidal records, deposition rates follow hyperbolic contour lines when expressed as a function of sediment concentration and median grain size. We also observe that when using a median sediment grain size D50 = 50 μm and sediment concentrations derived from satellite data, modeled deposition rates are much lower than when using field data. We find that the deposition of coarse, concentrated sediment is necessary for platforms in the upper tidal frame to withstand sea level rise, suggesting a strong dependance on infrequent high-deposition events. This is particularly true for marshes that are very high in the tidal frame, making accretion increasingly storm-driven as marsh platforms gain elevation. Finally, we reflect on the capacity of marshes to regenerate after erosion events within a context of changing sediment supply conditions

Cartagena in terra firma Americae sita : ichnographice repraesentata et recusa Norimbergae

IrtokarttaNimiönkehyksissä myös: Neu und verbesserter Plan des Hafens von Carthagena in America ... nach dem Entwurf des Pr. Chassereau ... nach Engelland gebracht. und ans Liecht gegebenNeu und verbesserte Plan der St. u. Hafens Havana auf der Ins. Cuba 23,3 x 27,8 cm ; Cartagena in terra firma Americae sita 23 x 28 cm ; Lisäkartta 6,5 x 12,2, c

Developing a Rubric for the Evaluation of 5th-12th Grade Science Mobile Applications: The Design of MASS

This paper details the process of creating, developing and testing a mobile science application rubric so as to aid secondary science classroom teachers in selecting and rating science applications for a K-12 student target population and its curricular needs. Quantitative and qualitative data collected during four design cycles resulted in the Mobile App Selection for Science (MASS) Rubric, comprising six items on a four-point response scale. Further comparison of the science content-specific MASS rubric with a general mobile app selection rubric (Evaluation Rubric for Mobile Applications; ERMA) revealed expected results with three item pairs (Pair A, Pair C, and Pair D) demonstrating concurrent validity through significant correlations and one pair (Pair B) displaying the expected divergent validity. Additionally, paired t-tests among each pair indicated a significant difference in participants’ ratings of the apps using the two rubrics

Integrating Technology in Content Methods Courses: A Co-Teaching Experience

The purpose of this research is to investigate the viability of co-teaching between instructional technology and content methods faculty to promote technology integration in content methods courses. This study also focuses on preservice teachers\u27 evolving perception of technology integration through participation in this collaborative teaching and learning environment