An Analysis of Cooperating Teacher Feedback: A Qualitative Inquiry

Cooperating teachers are a key component to the success of student teaching internships, serving an integral part in “raising” a teacher. To effectively facilitate the student teaching internship, teacher preparation programs must identify cooperating teachers who align philosophically with the pedagogical training delivered by university programs (Korthagen & Kessels, 1999; Tom, 1997), specifically, cooperating teachers who can reinforce the theoretical framework underpinning the professional coursework pre-service teachers experience in university teacher preparation programs. This qualitative study sought to better understand the feedback provided to future school-based agricultural education (SBAE) teachers during their student teaching experience. Through initial and secondary coding, the research team identified themes among the feedback provided to student teachers by their cooperating teachers. The study revealed cooperating teacher feedback reflects the pedagogical training provided via the teacher preparation program, specifically, around effective teaching behaviors. Understanding the cooperating teacher feedback provides insight for teacher preparation programs

MHD simulations of the formation and propagation of protostellar jets to observational length scales

We present 2.5-D global, ideal MHD simulations of magnetically and rotationally driven protostellar jets from Keplerian accretion discs, wherein only the initial magnetic field strength at the inner radius of the disc, $B_{\rm i}$, is varied. Using the AMR-MHD code AZEUS, we self-consistently follow the jet evolution into the observational regime ($>10^3\,\mathrm{AU}$) with a spatial dynamic range of $\sim6.5\times10^5$. The simulations reveal a three-component outflow: 1) A hot, dense, super-fast and highly magnetised 'jet core'; 2) a cold, rarefied, trans-fast and highly magnetised 'sheath' surrounding the jet core and extending to a tangential discontinuity; and 3) a warm, dense, trans-slow and weakly magnetised shocked ambient medium entrained by the advancing bow shock. The simulations reveal power-law relationships between $B_{\rm i}$ and the jet advance speed, $v_{\rm jet}$, the average jet rotation speed, $\langle v_\varphi\rangle$, as well as fluxes of mass, momentum, and kinetic energy. Quantities that do not depend on $B_{\rm i}$ include the plasma-$\beta$ of the transported material which, in all cases, seems to asymptote to order unity. Jets are launched by a combination of the 'magnetic tower' and 'bead-on-a-wire' mechanisms, with the former accounting for most of the jet acceleration---even for strong fields---and continuing well beyond the fast magnetosonic point. At no time does the leading bow shock leave the domain and, as such, these simulations generate large-scale jets that reproduce many of the observed properties of protostellar jets including their characteristic speeds and transported fluxes.Comment: 26 pages, 16 figures. Accepted for publication in MNRA

Pebble dynamics and accretion onto rocky planets. II. Radiative models

We investigate the effects of radiative energy transfer on a series of nested-grid, high-resolution hydrodynamic simulations of gas and particle dynamics in the vicinity of an Earth-mass planetary embryo. We include heating due to the accretion of solids and the subsequent convective motions. Using a constant embryo surface temperature, we show that radiative energy transport results in a tendency to reduce the entropy in the primordial atmosphere, but this tendency is alleviated by an increase in the strength of convective energy transport, triggered by a correspondingly increased super-adiabatic temperature gradient. As a consequence, the amplitude of the convective motions increase by roughly an order of magnitude in the vicinity of the embryo. In the cases investigated here, where the optical depth towards the disk surface is larger than unity, the reduction of the temperature in the outer parts of the Hill sphere relative to cases without radiative energy transport is only $\sim$100K, while the mass density increase is on the order of a factor of two in the inner parts of the Hill sphere. Our results demonstrate that, unless unrealistically low dust opacities are assumed, radiative cooling in the context of primordial rocky planet atmospheres can only become important after the disk surface density has dropped significantly below minimum-mass-solar-nebula values.Comment: 5 pages, 4 figures, 2 appendices; MNRAS Letters, accepte

The influence of shc proteins on the whole body energetic response to calorie restriction initiated in 3-month-old mice.

There is increasing evidence that Shc proteins play a role in energy metabolism, and we have previously reported that knockdown of Shc proteins influences the energetic response to acute (3 days) calorie restriction (CR) in 18-month-old mice. Whether Shc proteins play a role in the metabolic response to CR in younger mice has yet to be elucidated. Hence, we sought to determine the impact of 3 days and longer term (2 months) CR on energy expenditure (EE) and respiratory quotient (RQ) in 3 month-old Shc knockout (ShcKO) and wild-type (WT) mice. ShcKO mice decreased (P < 0.001) EE normalized for body weight (EEBW) by 3 days of CR, while no such change was observed in WT animals. However, both ShcKO and WT mice decreased (P < 0.001) EEBW at 2 months of CR and there were no differences in body weight between the ShcKO and WT mice at either 3 days or 2 months of CR. Consistent with increased fatty acid oxidation, only ShcKO mice maintained decreased (P < 0.001) 24 h RQ through 2 months of CR, suggesting that they were able to maintain increased fatty acid oxidation for a longer period of time than WT mice. These results indicate that Shc proteins may contribute to some of the acute energetic responses to CR

The influence of shc proteins and aging on whole body energy expenditure and substrate utilization in mice.

While it has been proposed that Shc family of adaptor proteins may influence aging by regulating insulin signaling and energy metabolism, the overall impact of Shc proteins on whole body energy metabolism has yet to be elucidated. Thus, the purpose of this study was to determine the influence of Shc proteins and aging on whole body energy metabolism in a mouse model under ambient conditions (22°C) and acute cold exposure (12°C for 24 hours). Using indirect respiration calorimetry, we investigated the impact of Shc proteins and aging on EE and substrate utilization (RQ) in p66 Shc-/- (ShcKO) and wild-type (WT) mice. Calorimetry measurements were completed in 3, 15, and 27 mo mice at 22°C and 12°C. At both temperatures and when analyzed across all age groups, ShcKO mice demonstrated lower 24 h total EE values than that of WT mice when EE data was expressed as either kJ per mouse, or adjusted by body weight or crude organ mass (ORGAN) (P≤0.01 for all). The ShcKO mice also had higher (P<0.05) fed state RQ values than WT animals at 22°C, consistent with an increase in glucose utilization. However, Shc proteins did not influence age-related changes in energy expenditure or RQ. Age had a significant impact on EE at 22°C, regardless of how EE data was expressed (P<0.05), demonstrating a pattern of increase in EE from age 3 to 15 mo, followed by a decrease in EE at 27 mo. These results indicate a decline in whole body EE with advanced age in mice, independent of changes in body weight (BW) or fat free mass (FFM). The results of this study indicate that both Shc proteins and aging should be considered as factors that influence energy expenditure in mice

Are Markets for Vulnerabilities Effective?

Security vulnerabilities are inextricably linked to information systems. Unable to eliminate these vulnerabilities, the security community is left to minimize their impact. Unfortunately, current reward structures may be skewed towards benefiting nefarious usage of vulnerability information rather than responsible disclosure. Recently suggested market-based mechanisms offer some hope by providing incentives to responsible security researchers. However, concerns exist that any benefits gained through increased incentives may be more than lost through information leakage. Using two years of security alert data, we examine the effectiveness of market-based mechanisms. While market-mechanisms do not reduce the likelihood that a vulnerability will be exploited, we find evidence that markets increase the time to vulnerability exploit and decrease the overall volume of alerts

Potential Mentoring Impacts on Oklahoma Induction-Year School-Based Agricultural Education Teachers: A Modified Delphi Study

Literature supports benefits of mentoring for induction-year school-based agricultural education (SBAE) teachers. Yet for the past 15 years, no structured mentoring program has been offered for Oklahoma SBAE induction-year teachers. This study sought to find consensus among an expert panel representing Oklahoma SBAE regarding the impact on induction-year SBAE teachers without a structured mentoring program. Panel members were asked to respond to three open-ended questions representing goals, outcomes, and impacts of a mentoring program. Sixty-two unique statements representing eight themes met consensus. Themes included building mentoring relationships, effective emotional management, effective SBAE program management, impact to the profession, student learning, teacher retention, introduction to school climate, and reinforcing effective teaching behaviors. Oklahoma SBAE induction-year teachers and programs are negatively impacted from the lack of a structured mentoring program. The planning, funding, and implementation of a mentoring program for Oklahoma SBAE induction-year teachers should be a focus of professional development

Barriers to Conducting Supervised Agricultural Experiences as Perceived by Preservice Education Teachers

The purpose of this descriptive study was to assess preservice agriculture teachers’ perceptions of the importance of Supervised Agricultural Experience (SAE) and their views on barriers to conducting SAE. A census of the sophomore-level agricultural education course at Oklahoma State University was conducted to measure perceptions at the beginning and end of the course. This study was framed upon Ajzen’s Theory of Planned Behavior. Results indicated that preservice teachers perceived SAE was an important component of agricultural education and important at the secondary school they attended. The greatest barrier to conducting SAE was their lack of familiarity with newer SAE categories. This was true at both the beginning and end of the course. It is recommended that preservice teachers receive instruction on and experiences in all types of SAE. This would increase the likelihood of preservice teachers perceiving they have control over this barrier regarding SAE implementation. This cohort of preservice teachers should be surveyed over time to determine change in their perceptions of barriers to SAE implementation as they progress in the agricultural education program and through their careers. Further, the views of in-service teachers should also be assessed to determine if perceived barriers differ with professional experience

Biophysical Characterization of the Sequsingle-Stranded DNA-Binding Properties of Mouse Pur : a Repressor of Smooth Muscle -Actin Gene Expression

ABSTRACT Regulation of gene transcription by structural interconversions of genomic DNA is an emerging biochemical and genetic paradigm that adds to the already diverse repertoire of eukaryotic gene regulatory mechanisms. The appearance of paranemic structures coincident with changes in gene activity, as well as participation of transcription factors that recognize and bind single-stranded DNA at numerous gene promoters in vivo illustrates the authenticity of this concept and its importance in cellular homeostasis. Despite its acceptance, this concept has been minimally described at the biochemical and biophysical levels, as the means by which sequence-specific single-stranded DNAbinding proteins exert transcriptional influence in double-stranded genomes remains largely undefined. Pur is a sequence-specific single-stranded DNA/RNA-binding protein that acts as a repressor of smooth muscle -actin (SM A) gene transcription, and mRNA translation. SM A is an important cytoskeletal protein that contributes contractile, antimigratory, and nonproliferative functions in smooth muscle. In concert with Pur protein family member Pur , and Y-box protein MSY1, Pur enacts repression of SM A gene expression by interacting with a cryptic cis-regulatory element in the 5’ region of the SM A promoter that has been shown to transiently adopt single-stranded conformations in vivo, and to confer transcriptional activation when trans-activator occupied while in a doublestranded conformation. Downregulation of SM A gene expression has been identified to be a contributing factor to cardiovascular disease progression; therefore a thorough understanding of SM A repression mechanisms is critical for clinical management of these conditions. Although highly homologous at the primary sequence level, Pur and Pur display significant conserved regions of sequence divergence that suggest these paralogs exert distinct cellular functions in various vertebrate classes. A goal of the studies presented herein was to delineate exhibited functional differences with respect to SM A repression in pertinent mouse cell lines. Loss-of-function and chromatin immunoprecipitation studies verified that Pur differs from Pur in that Pur is the dominant Pur protein repressor of SM A expression in embryonic fibroblasts and vascular smooth muscle cells, although by different, cell type-specific mechanisms. Biophysical assessment of Pur single-stranded DNA binding properties showed that despite the ability of Pur to self-dimerize in the absence of nucleic acid, Pur binds to the cryptic SM A enhancer by a sequential and cooperative mechanism, with remarkable affinity and a terminal stoichiometry of 2 to 1. Footprinting and in vitro binding site characterization confirms two Pur binding sites exist within this element and display slight degeneracy from a proposed Pur protein-binding consensus motif. These findings delineate binding mechanisms adopted by Pur and provide a means to identify putative Pur binding sites throughout the genome

Kepler Mission Stellar and Instrument Noise Properties Revisited

An earlier study of the Kepler Mission noise properties on time scales of primary relevance to detection of exoplanet transits found that higher than expected noise followed to a large extent from the stars, rather than instrument or data analysis performance. The earlier study over the first six quarters of Kepler data is extended to the full four years ultimately comprising the mission. Efforts to improve the pipeline data analysis have been successful in reducing noise levels modestly as evidenced by smaller values derived from the current data products. The new analyses of noise properties on transit time scales show significant changes in the component attributed to instrument and data analysis, with essentially no change in the inferred stellar noise. We also extend the analyses to time scales of several days, instead of several hours to better sample stellar noise that follows from magnetic activity. On the longer time scale there is a shift in stellar noise for solar-type stars to smaller values in comparison to solar values.Comment: 10 pages, 8 figures, accepted by A