Investigating Teachers\u27 Content Knowledge and Pedogogical Content Knowledge in a Middle School Physical Science Curriculum on Force and Motion

Teaching is a profession that requires the incorporation of many types of knowledge in order to create effective instructional experiences that promote student learning. Teachers need to blend their knowledge of the content with the methods for delivering that content and an understanding of their students\u27 thinking. With increasing concern in the United States over student achievement in science and mathematics, there is ongoing discussion about which elements of teacher knowledge most directly correlate with effective instruction. How do specific strands of teacher knowledge blend to influence student learning outcomes? This study explores the roles of teacher content knowledge (CK) and pedagogical content knowledge (PCK), particularly teacher knowledge of student ideas (KSI), in the context of a middle-school physical science curriculum on force and motion. The study takes place within the Maine Physical Sciences Partnership (MainePSP). The primary focus of the MainePSP is the professional development of physical science instructors in grades 6-9 via curriculum renewal using common instructional resources across multiple school districts in rural Maine. Teachers and their students were given multiple-choice assessment items to examine teachers’ CK as well as the learning gains of their students. To measure teacher KSI, teachers were additionally asked to predict if a significant portion of their students [\u3e10%) would select a multiple-choice option on a certain assessment item and to articulate student reasoning for selecting that choice. For both the CK and the KSI surveys, teacher performance varied widely, between 10% and 90% of the maximum score on each survey represented, with little to no correlation between CK and KSI scores. Overall results from the student assessment indicate that students come into the curriculum with incorrect ideas about force and motion, but are on par with comparable populations seen in the literature. Furthermore, there was little shift in student understanding of force and motion concepts after instruction of the curriculum. Additionally, teacher CK and KSI were not strong predictors of student performance when related to the narrow learning gains observed. We discuss possible factors to which this lack of correlation may be attributed, including the implementation process and elements of the curriculum itself, and also the resolution of the KSI instrument. Recommendations for future research are provided

Functional responses can unify invasion ecology.

We contend that invasion ecology requires a universal, measurable trait of species and their interactions with resources that predicts key elements of invasibility and ecological impact; here, we advocate that functional responses can help achieve this across taxonomic and trophic groups, among habitats and contexts, and can hence help unify disparate research interests in invasion ecology

Kinetic Assessment and Therapeutic Modulation of Metabolic and Inflammatory Profiles in Mice on a High-Fat and Cholesterol Diet

The kinetics of metabolic and inflammatory parameters associated with obesity were evaluated in a murine diet-induced obesity (DIO) model using a diet high in fat and cholesterol. Cellular infiltration and mediator production were assessed and shown to be therapeutically modulated by the PPARgamma agonist rosiglitazone. C57BL/6 mice were maintained on a 45% fat/ 0.12% cholesterol (HF/CH) or Chow diet for 3, 6, 16, or 27 weeks. Flow cytometry was employed to monitor peripheral blood monocytes and adipose tissue macrophages (ATM). Gene expression and protein analysis methods were used to evaluate mediator production from total epididymal fat (EF), stromal vascular fraction (SVF), and sorted SVF cells. To investigate therapeutic intervention, mice were fed a HF/CH diet for 12 weeks and then a diet formulated with rosiglitazone (5 mg/kg) for an additional 6 weeks. A HF/CH diet correlated with obesity and a dramatic proinflammatory state. Therapeutic intervention with rosiglitazone attenuated the HF/CH induced inflammation. In addition, a novel population was found that expressed the highest levels of the pro-inflammatory mediators CCL2 and IL-6

Assessing the ecological impacts of invasive species based on their functional responses and abundances

Invasive species management requires allocation of limited resources towards the proactive mitigation of those species that could elicit the highest ecological impacts. However, we lack predictive capacity with respect to the identities and degree of ecological impacts of invasive species. Here, we combine the relative per capita effects and relative field abundances of invader as compared to native species into a new metric, “Relative Impact Potential” (RIP), and test whether this metric can reliably predict high impact invaders. This metric tests the impact of invaders relative to the baseline impacts of natives on the broader ecological community. We first derived the functional responses (i.e. per capita effects) of two ecologically damaging invasive fish species in Europe, the Ponto-Caspian round goby (Neogobius melanostomus) and Asian topmouth gudgeon (Pseudorasbora parva), and their native trophic analogues, the bullhead (Cottus gobio; also C. bairdi) and bitterling (Rhodeus amarus), towards several prey species. This establishes the existence and relative strengths of the predator-prey relationships. Then, we derived ecologically comparable field abundance estimates of the invader and native fish from surveys and literature. This establishes the multipliers for the above per capita effects. Despite both predators having known severe detrimental field impacts, their functional responses alone were of modest predictive power in this regard; however, incorporation of their abundances relative to natives into the RIP metric gave high predictive power. We present invader/native RIP biplots that provide an intuitive visualisation of comparisons among the invasive and native species, reflecting the known broad ecological impacts of the invaders. Thus, we provide a mechanistic understanding of invasive species impacts and a predictive tool for use by practitioners, for example, in risk assessments

Lilliput

Catalog for the exhibition Lilliput held at the Seton Hall University Walsh Gallery, June 8 - July 24, 2009. Curated by Jeanne Brasile and Asha Ganpat. Includes an essay by Jeanne Brasile and Asha Ganpat. Includes color illustrations

Predicting predatory impact of juvenile invasive lionfish (Pterois volitans) on a crustacean prey using functional response analysis: effects of temperature, habitat complexity and light regimes

The ecological implications of biotic interactions, such as predator-prey relationships, are often context-dependent. Comparative functional responses analysis can be used under different abiotic contexts to improve understanding and prediction of the ecological impact of invasive species. Pterois volitans (Lionfish) [Linnaeus 1758] is an established invasive species in the Caribbean and Gulf of Mexico, with a more recent invasion into the Mediterranean. Lionfish are generalist predators that impact a wide range of commercial and non-commercial species. Functional response analysis was employed to quantify interaction strength between lionfish and a generic prey species, the shrimp (Paleomonetes varians) [Leach 1814], under the contexts of differing temperature, habitat complexity and light wavelength. Lionfish have prey population destabilising Type II functional responses under all contexts examined. Significantly more prey were consumed at 26 °C than at 22 °C. Habitat complexity did not significantly alter the functional response parameters. Significantly more prey were consumed under white light and blue light than under red light. Attack rate was significantly higher under white light than under blue or red light. Light wavelength did not significantly change handling times. The impacts on prey populations through feeding rates may increase with concomitant temperature increase. As attack rates are very high at low habitat complexity this may elucidate the cause of high impact upon degraded reef ecosystems with low-density prey populations, although there was little protection conferred through habitat complexity. Only red light (i.e. dark) afforded any reduction in predation pressure. Management initiatives should account for these environmental factors when planning mitigation and prevention strategies

Screening out irrelevant cell-based models of disease

The common and persistent failures to translate promising preclinical drug candidates into clinical success highlight the limited effectiveness of disease models currently used in drug discovery. An apparent reluctance to explore and adopt alternative cell-and tissue-based model systems, coupled with a detachment from clinical practice during assay validation, contributes to ineffective translational research. To help address these issues and stimulate debate, here we propose a set of principles to facilitate the definition and development of disease-relevant assays, and we discuss new opportunities for exploiting the latest advances in cell-based assay technologies in drug discovery, including induced pluripotent stem cells, three-dimensional (3D) co-culture and organ-on-a-chip systems, complemented by advances in single-cell imaging and gene editing technologies. Funding to support precompetitive, multidisciplinary collaborations to develop novel preclinical models and cell-based screening technologies could have a key role in improving their clinical relevance, and ultimately increase clinical success rates

INTERACTIONS OF DNA POLYMERASE THETA AND KU70/80 WITH OXIDATIVE DNA DAMAGE

Oxidized abasic sites (L, C4-AP, and DOB) are formed by ionizing radiation, reactive oxygen species, and some chemotherapeutics. Like abasic sites (AP), these lesions are cytotoxic and mutagenic and must be repaired, primarily by base excision repair (BER). If left unrepaired, abasic lesions stall replication and induce mutations. Repair of oxidized abasic lesions exhibits unique challenges, however. C4-AP and DOB inactivate the lyase activity of the repair enzymes DNA polymerase β and λ. Recently, several other enzymes were shown to possess lyase activity, allowing them to excise abasic lesions. Among these are DNA polymerase θ (Pol θ) and Ku70/80 (Ku). As Pol θ promotes resistance to cancer therapies which form oxidized abasic sites, the repair and replication of these lesions by Pol θ is potentially important. Ku is a core factor for non-homologous end-joining and removes AP from double strand breaks (DSBs). The interaction of Ku with oxidized abasic sites near DSB termini is potentially important for the response to ionizing radiation, which is used as a cancer treatment. Synthetic oligonucleotides containing abasic and oxidized abasic sites were prepared, and their repair or replication by Pol θ was analyzed. Pol θ bypasses C4-AP and L with reduced efficiency relative to AP and has a strong propensity to induce frameshift mutations during bypass of AP, C4-AP, L, and the oxidized nucleobase, thymidine glycol. Studies on the repair of C4-AP and DOB by Pol θ showed that Pol θ is inactivated by pC4-AP, which covalently modifies Lys2383, but not by DOB. Site-directed mutagenesis showed that Lys2383 is essential for both polymerase and lyase activity of Pol θ. These results have unveiled the primary nucleophile (Lys2383) responsible for Pol θ lyase activity. The repair of oxidized abasic sites by Ku was also analyzed. Ku exhibits differential repair capability on different oxidized abasic lesions. C4-AP and DOB are excised more efficiently than AP, yet Ku cannot excise L. Failure to remove this lesion can potentially inhibit repair of a DSB. Unlike Pol θ which was modified by pC4-AP, modification of Ku was not detected following repair of DOB or C4-AP

Analysis of the most common concept inventories in physics: What are we assessing?

Assessing student learning is a cornerstone of educational practice. Standardized assessments have played a significant role in the development of instruction, curricula, and educational spaces in college physics. However, the use of these assessments to evaluate student learning is only productive if they continue to align with our learning goals. Recently, there have been calls to elevate the process of science (“scientific practices”) to the same level of importance and emphasis as the concepts of physics (“core ideas” and “crosscutting concepts”). We use the recently developed Three-Dimensional Learning Assessment Protocol to investigate how well the most commonly used standardized assessments in introductory physics (i.e., concept inventories) align with this modern understanding of physics education’s learning goals. We find that many of the questions on concept inventories do elicit evidence of student understanding of core ideas, but do not have the potential to elicit evidence of scientific practices or crosscutting concepts. Furthermore, we find that the individual scientific practices and crosscutting concepts that are assessed using these tools are limited to a select few. We discuss the implications that these findings have on designing and testing curricula and instruction both in the past and for the future