The Impact of Formal Teacher Leadership Programs on Teachers’ Instructional Practices

Teacher leadership is a growing reform in the United States, with almost 300 active programs that are preparing, positioning, and/or rewarding teacher leaders (Berg et al., 2019). Despite this plethora of activity, there is relatively little empirical research on the influence of teacher leadership on teacher practice. This study adds to the research base on how teacher leaders influence instruction. The study focuses on the instructional influence of teacher leaders in formal teacher leadership programs in four districts in three American states. Although the programs had different emphases and structures, all four provided training, ongoing support, and formal school positions for teacher leaders, who were charged with working with teachers to support instructional improvement. Using survey data from approximately 1,050 teachers in 45 schools in the four districts and interview data from a subset of schools, we examined the relationship between the activities of teacher leaders and teacher reports of teacher leader influence and changes in instruction. The findings indicate that teachers who report being influenced by their teacher leader also report more frequently planning with their teacher leader, engaging in professional learning activities with their teacher leader, and participating in observations and feedback with their teacher leader. Additionally, higher levels of teacher leader influence are associated with teacher reports of change in instructional practice

Plant adaptation in the Great Basin and Colorado Plateau

Journal ArticleAdaptive features of plants of the Great Basin are reviewed. The combination of cold winters and an arid to semiarid precipitation regime results in the distinguishing features of the vegetation in the Great Basin and Colorado Plateau. The primary effects of these climatic features arise from how they structure the hydrologic regime. Water is the most limiting factor to plant growth, and water is most reliably available in the early spring after winter recharge of soil moisture. This factor determines many characteristics of root morphology, growth phenology of roots and shoots, and photosynthetic physiology. Since winters are typically cold enough to suppress growth. and drought limits growth during the summer, the cool temperatures characteristic of the peak growing season are the second most important climatic factor influencing plant habit and performance. The combination of several distinct stress periods, including low-temperature stress in winter and spring and high-temperature stress combined with drought in summer, appears to have limited plant habit to a greater degree than found in the warm deserts to the south

The Influence of Teacher Leadership Programs on Teacher Leaders, Teachers, Schools, and Districts

Teacher leadership is increasingly recognized as a promising strategy to improve the quality of instruction in U.S. schools. Despite the rising number of teacher leadership programs in the country, there is a paucity of knowledge about the work that teacher leaders (TLs) engage in, how educators experience teacher leadership and the impacts of these efforts on teacher leaders themselves and on districts, schools, teachers, and students. In response, the Nellie Mae Education Foundation (NMEF) supported the Consortium for Policy Research in Education (CPRE) to investigate educators’ experiences with teacher leadership and describe the impacts of this improvement strategy

The Influence of Teacher Leadership Programs on Teacher Leaders, Teachers, Schools, and Districts

Teacher leadership is increasingly recognized as a promising strategy to improve the quality of instruction in U.S. schools. Despite the rising number of teacher leadership programs in the country, there is a paucity of knowledge about the work that teacher leaders (TLs) engage in, how educators experience teacher leadership and the impacts of these efforts on teacher leaders themselves and on districts, schools, teachers, and students. In response, the Nellie Mae Education Foundation (NMEF) supported the Consortium for Policy Research in Education (CPRE) to investigate educators’ experiences with teacher leadership and describe the impacts of this improvement strategy

The effects of resource availability and environmental conditions on genetic rankings for carbon isotope discrimination during growth in tomato and rice

Carbon isotope discrimination (Δ) is frequently used as an index of leaf intercellular CO2 concentration (ci) and variation in photosynthetic water use efficiency. In this study, the stability of Δ was evaluated in greenhouse grown tomato and rice with respect to variable growth conditions including temperature, nutrient availability, soil flooding (in rice), irradiance, and root constriction in small soil volumes. Δ exhibited several characteristics indicative of contrasting set-point behavior among genotypes of both crops. These included generally small main environmental effects and lower observed levels of G x E interaction across the diverse treatments than observed in associated measures of relative growth rate, photosynthetic rate, biomass allocation pattern, or specific leaf area. Growth irradiance stood out among environmental parameters tested as having consistently large main affects on Δ for all genotypes screened in both crops. We suggest that this may be related to contrasting mechanisms of stomatal aperture modulation associated with the different environmental variables. For temperature and nutrient availability, feedback processes directly linked to ci and/or metabolite pools associated with ci may have played the primary role in coordinating stomatal conductance and photosynthetic capacity. In contrast, light has a direct effect on stomatal aperture in addition to feedback mediated through ci

Large-scale assessment of Extractables and Leachables in single-use bags for biomanufacturing using ultra high performance liquid chromatography coupled to quadrupole-orbitrap mass spectrometry

Single-use technologies (SUTs) are increasingly used in biopharmaceutical manufacturing processes. Despite their advantages, these plastic assemblies draw concern because they are a potential source of contamination due to extractable and leachable compounds (E&Ls) that result from residual polymeric fragments and different additives used in their manufacture1. Characterizing E&Ls from such materials is a necessary step in establishing their suitability for use. There is evidence of some cytotoxic compounds that leach out of single-use bags into cell culture media in concentrations are deleterious to CHO cell growth, even at trace levels2. Given the potential for these substances to adversely affect biopharmaceutical production, this discovery clearly shows an urgent need for analytical techniques to identify and quantitatively assess compounds resulting from the extraction of SUS components. This study was focused specifically in single-use bags (SUBs), one important application of the disposable technologies, used for the production of therapeutic antibodies, proteins and vaccines. 34 single-use bags from different suppliers were extracted under conditions that are relevant for the characterisation of E&Ls. Extraction with different model solvents was intended to establish a comprehensive extractables profile: water for injection, isopropanol:H2O (1:1), 0.1 M H3PO4 and 50mM NH4CH3COO pH 9.5, while extraction with chemically defined cell culture media was used for leachable assessment. This analysis is challenging as leachables usually exist at trace levels within a very complex matrix. For this reason, a simple and fast analytical method based on a sample treatment by dispersive liquid-liquid microextraction (DLLME) was also developed and applied for analyte preconcentration and matrix elimination. Then, the extracts were analysed by LC-Orbitrap-MS, with high mass resolution performance and exceptional mass accuracy for the detection and identification of non-volatile E&Ls in SUBs. 130 E&Ls were identified, with many of these compounds being polymer additives or their degradation products. Interestingly, some leachables were not found during extractables analysis, suggesting that they might be produced by the interaction of components of the media with compounds from bags. Multivariate analysis performed on the analytical data established significant correlations between the type and concentration of compounds and bags features as brand, manufacturing date and type of polymer. New production techniques have allowed to develop new types of polymers and the advent of regulatory issues that limit/ban the use of certain raw materials and additives has produced a change in the nature of E&Ls. Consequently, it is necessary to provide practical and versatile guidelines for confident determination of these substances that would enable early identification of non-satisfactory films for control and improvement of SUBs. The analytical workflow that is presented has all the necessary features to be used as part of the quality control in bags manufacturing. 1 Gao, Y.; Allison, N. Extractables and leachables issues with the application of single use technology in the biopharmaceutical industry. J Chem Technol Biotechnol. 2016, 91, 289–295. 2 Hammond, M.; Nunn, H.; Rogers, G.; Lee, H.; Marghitoiu, A.-L.; Perez, L.; Nashed-Samuel, Y.; Anderson, C.; Vandiver, M.; Kline, S. Identification of a Leachable Compound Detrimental to Cell Growth in Single-Use Bioprocess Containers. PDA J. Pharm. Sci. Technol. 2013, 67, 123–134

Carbonate determination in soils by mid-IR spectroscopy with regional and continental scale models

A Partial Least Squares (PLS) carbonate (CO3) prediction model was developed for soils throughout the contiguous United States using mid-infrared (MIR) spectroscopy. Excellent performance was achieved over an extensive geographic and chemical diversity of soils. A single model for all soil types performed very well with a root mean square error of prediction (RMSEP) of 12.6 g kg-1 and was further improved if Histosols were excluded (RMSEP 11.1 g kg-1). Exclusion of Histosols was particularly beneficial for accurate prediction of CO3 values when the national model was applied to an independent regional dataset. Little advantage was found in further narrowing the taxonomic breadth of the calibration dataset, but higher precision was obtained by running models for a restricted range of CO3. A model calibrated using only on the independent regional dataset, was unable to accurately predict CO3 content for the more chemically diverse national dataset. Ten absorbance peaks enabling CO3 prediction by mid-infrared (MIR) spectroscopy were identified and evaluated for individual and combined predictive power. A single-band model derived from an absorbance peak centered at 1796 cm-yielded the lowest RMSEP of 13.5 g kg-1 for carbonate prediction compared to other single-band models. This predictive power is attributed to the strength and sharpness of the peak, and an apparent minimal overlap with confounding co-occurring spectral features of other soil components. Drawing from the 10 identified bands, multiple combinations of 3 or 4 peaks were able to predict CO3 content as well as the full-spectrum national models. Soil CO3 is an excellent example of a soil parameter that can be predicted with great effectiveness and generality, and MIR models could replace direct laboratory measurement as a lower cost, high quality alternative

Analysis of a phase variable restriction modification system of the human gut symbiont Bacteroides fragilis

The genomes of gut Bacteroidales contain numerous invertible regions, many of which contain promoters that dictate phase-variable synthesis of surface molecules such as polysaccharides, fimbriae, and outer surface proteins. Here, we characterize a different type of phase-variable system of Bacteroides fragilis, a Type I restriction modification system (R-M). We show that reversible DNA inversions within this R-M locus leads to the generation of eight specificity proteins with distinct recognition sites. In vitro grown bacteria have a different proportion of specificity gene combinations at the expression locus than bacteria isolated from the mammalian gut. By creating mutants, each able to produce only one specificity protein from this region, we identified the R-M recognition sites of four of these S-proteins using SMRT sequencing. Transcriptome analysis revealed that the locked specificity mutants, whether grown in vitro or isolated from the mammalian gut, have distinct transcriptional profiles, likely creating different phenotypes, one of which was confirmed. Genomic analyses of diverse strains of Bacteroidetes from both host-associated and environmental sources reveal the ubiquity of phase-variable R-M systems in this phylum

Observations of the variation in aerosol and cloud microphysics along the 20°s transect on 13 november 2008 during VOCALS-REx

Observations are presented of the structure of the marine boundary layer (MBL) in the southeastern Pacific made with the U.K. BAe 146 aircraft on 13 November 2008 as it flew at a variety of altitudes along 20°S between the coast of Chile and a buoy 950 km offshore during the Variability of American Monsoon Systems (VAMOS) Ocean-Cloud-Atmosphere-Land Study (VOCALS) Regional Experiment (REx). The purpose of the study is to determine the variations along the 20°S transect in the clouds and boundary layer on this particular day as compared to the typical structure determined from the composite studies. The aircraft flew in three regions on this day: relatively continuous thick stratocumulus clouds, open cells, and closed cells. Results show three particular features. First, the results of the cloud microphysics are consistent with the typical behavior showing a decrease in aerosol particles by a factor of 3-4, and a decrease in cloud droplet number concentration westward from the coast from about 200 to 100 cm or less with a corresponding increase in the concentration of drizzle drops with a maximum in open cells. Sulfate was dominant in the aerosol mass. Second, there was evidence of decoupling of the marine boundary layer that coincided with a change in the cloud type from stratiform to convective. The case differs from the average found in VOCALS in that the decoupling is not consistent with the deepening-warming idea. Precipitation is thought to possibly be the cause instead, suggesting that aerosol might play a controlling role in the cloud-boundary layer structure. Finally, cold pools were observed in the MBL from the dropsonde data