Evaluating Evaluations: Using Teacher Surveys to Strengthen Implementation

Substantial progress has been made in the last several years in establishing meaningful teacher evaluation systems in K12 education, creating the foundation for improving teacher performance. Evaluating teachers is necessary but not sufficient, however, to improve instruction toward the ultimate goal of increasing student achievement. The evaluation reform movement will have failed if these more rigorous evaluations do not translate into system-wide improvements in teacher effectiveness within the next five years. To convert evaluation information into more effective teaching, teachers, principals, and system leaders need to embrace a culture of ongoing, two-way feedback and a commitment to continuous improvement

Missouri farm prices for 25 years

Publication authorized February 15, 1935

The impact of acute calcium intake on bone turnover markers during a training day in elite male rowers

Introduction: While an acute exercise session typically increases bone turnover markers (BTM), the impact of subsequent sessions and the interaction with pre-exercise calcium intake remains unclear despite the application to the ‘real life’ training of many competitive athletes. Methods: Using a randomized crossover design, elite male rowers (n = 16) completed two trials, a week apart, consisting of two 90-minute rowing ergometer sessions (Ex1, Ex2) separated by 150 minutes. Prior to each trial, participants consumed a high (CAL: ~1000 mg) or isocaloric low (CON: \u3c 10 mg) calcium meal. Biochemical markers including parathyroid hormone: PTH; serum ionised calcium (iCa) and bone turnover markers (C-terminal telopeptide of type I collagen: β-CTX-I; osteocalcin: OC) were monitored from baseline to 3 hours post Ex2. Results: While each session caused perturbances of serum iCa, CAL maintained calcium concentrations above those of CON for most time points, 4.5 and 2.4 % higher post EX1 and EX2 respectively. The decrease in iCa in CON was associated with an elevation of blood PTH (p \u3c 0.05) and β-CTX-I (p \u3c 0.0001) over this period of repeated training sessions and their recovery, particularly during and after Ex2. Pre-exercise intake of calcium-rich foods lowered BTM over the course of a day with several training sessions. Conclusions: Pre-exercise intake of a calcium-rich meal prior to training sessions undertaken within the same day had a cumulative and prolonged effect on the stabilisation of blood iCa during exercise. In turn, this reduced the post-exercise PTH response, potentially attenuating the increase in markers of bone resorption. Such practical strategies may be integrated into the athlete’s overall sports nutrition plan, with the potential to safeguard long term bone health and reduce the risk of bone stress injuries

Hard X-ray photoelectron spectroscopy study of copper formation by metal salt inclusion in a polymer film

In this work we present the results of a Hard X-ray Photoelectron Spectroscopy (HAXPES) study on the creation of metallic copper layers via metal-salt infiltration into a poly-2-vinylpyridine (P2VP) film. Metal salt inclusion is a wet chemistry process which allows for the fabrication of both metal and metal oxide films by means of infiltrating a receptive polymer thin film with metal salt precursors. A copper infiltrated P2VP film was subject to UV/Ozone treatment to form copper oxide and annealed in-vacuo to reduce the film to metallic copper. HAXPES and transmission electron microscope (TEM) measurements were used to study the polymer film before and after metal salt infiltration, along with analysis of the copper oxide created after UV/Ozone treatment. The results show successful infiltration of the metal salt into the polymer film, as well as complete conversion to copper oxide following UV/Ozone treatment and reduction to metallic copper with a subsequent in-situ anneal, which demonstrates the ability of the technique for the creation of several key integrated circuit features

Analysing trimethylaluminum infiltration intopolymer brushes using a scalable area selectivevapor phase process

Developing vapor phase infiltration (VPI) processes for area selective polymer nanopatterning requires substantial advancement in understanding precursor infiltration, precursor–polymer interaction and process parameters. In this work, infiltration receptive poly(2-vinylpyridine) (P2VP) and poly(4-vinylpyridine) (P4VP) brushes were exposed to a trimethylaluminum (TMA) VPI process and compared toa non-receptive polystyrene (PS) system. The interaction that takes place between TMA and P2VP/P4VPwas analysed in detail and we report on notable advantages in the use of P4VP, arising from the difference in position of the pyridinic nitrogen. The VPI process was performed in a commercial atomic layer deposition reactor and the effects of the fundamental process parameters on the three polymer brushes were investigated to ensure optimal area selectivity. In situX-ray photoelectron spectroscopy (XPS) measurements were supported by grazing angle Fourier transform infrared spectroscopy (GA-FTIR)and hard X-ray photoelectron spectroscopy (HAXPES). The report identifies several important factors when developing a VPI process to ensure area selectivity, while also demonstrating the use of novel pyridine containing polymers for VPI area selective purposes

Fabrication of sub-5 nm uniform zirconium oxide films on corrugated copper substrates by a scalable polymer brush assisted deposition method

We demonstrate a polymer brush assisted approach for the fabrication of continuous zirconium oxide (ZrO2) films over large areas with high uniformity (pin-hole free) on copper (Cu) substrates. This approach involves the use of a thiol-terminated polymethyl methacrylate brush (PMMA-SH) as the template layer for the selective infiltration of zirconium oxynitrate (ZrN2O7). The preparation of a highly uniform covalently grafted polymer monolayer on the Cu substrate is the critical factor in fabricating a metal oxide film of uniform thickness across the surface. Infiltration is reliant on the chemical interactions between the polymer functional group and the metal precursor. A following reductive H2 plasma treatment process results in ZrO2 film formation whilst the surface Cu2O passive oxide layer was reduced to a Cu/Cu2O interface. Fundamental analysis of the infiltration process and the resulting ZrO2 film was determined by XPS, and GA-FTIR. Results derived from these techniques confirm the inclusion of the ZrN2O7 into the polymer films. Cross-sectional transmission electron microscopy and energy dispersive X-ray mapping analysis corroborate the formation of ZrO2 layer at Cu substrate. We believe that this quick and facile methodology to prepare ZrO2 films is potentially scalable to other high-κ dielectric materials of high interest in microelectronic applications

How infants and young children learn about food: a systematic review

Early childhood is a critical time for establishing food preferences and dietary habits. In order for appropriate advice to be available to parents and healthcare professionals it is essential for researchers to understand the ways in which children learn about foods. This review summarizes the literature relating to the role played by known developmental learning processes in the establishment of early eating behavior, food preferences and general knowledge about food, and identifies gaps in our knowledge that remain to be explored. A systematic literature search identified 48 papers exploring how young children learn about food from the start of complementary feeding to 36 months of age. The majority of the papers focus on evaluative components of children’s learning about food, such as their food preferences, liking and acceptance. A smaller number of papers focus on other aspects of what and how children learn about food, such as a food’s origins or appropriate eating contexts. The review identified papers relating to four developmental learning processes: 1. Familiarization to a food through repeated exposure to its taste, texture or appearance. This was found to be an effective technique for learning about foods, especially for children at the younger end of our age range. 2. Observational learning of food choice. Imitation of others’ eating behavior was also found to play an important role in the first years of life. 3. Associative learning through flavor-nutrient and flavor-flavor learning. Although the subject of much investigation, conditioning techniques were not found to play a major role in shaping the food preferences of infants in the post-weaning and toddler periods. 4. Categorization of foods. The direct effects of the ability to categorize foods have been little studied in this age group. However, the literature suggests that what infants are willing to consume depends on their ability to recognize items on their plate as familiar exemplars of that food type

Metal size distribution in rainfall and snowmelt-induced runoff from three urban catchments

The size distribution of metals transported by urban runoff has implications for treatment type and design, predicting their mobility and evaluating their potential impact on receiving waters. There is an urgent need to better understand the distribution of metals between fractions, particularly those in the sub-dissolved fractions. As a contribution to addressing this need, this study characterises the size distribution of Cd, Cr, Cu, Ni, V and Zn using conventional and novel techniques. Data is presented as event mean concentrations (EMC) of a total of 18 rainfall and snowmelt events at three urban sites. For all studied metals in all events and at all sites, the contribution of the truly dissolved fraction made a greater contribution to the total concentrations than the colloidal fraction. Truly dissolved Cd and Zn concentrations contributed (on average) 26% and 28% respectively, of the total EMCs with truly dissolved Cu and Ni contributing (on average) 18%. In contrast, only 1% (V) and 3% (Cr) were identified in the truly dissolved fraction. The greatest contribution of truly dissolved Cd, Cu and Zn concentrations (relative to total oncentrations) were reported during rainfall events. However, no seasonal differences were identified and differences between the sites regarding the EMCs distribution by fractions were not at a statistically significant level (p N 0.05) for any metal or event. The loads of truly dissolved and colloidal metals did not follow the patterns of particulate metal loads indicating particulates are not the main source of subdissolved metals. The data suggests that ultrafiltration as a treatment technique would not efficiently mitigate the risks posed by metals to receiving water cologie

Surface, interface and thin film studies for nano & heat transfer applications

This thesis is focused on the study of surfaces, interfaces and thin films. The main goal of this project is to produce and examine thin films and interfaces that can lead to the development of heat transfer and nano applications. High-performance dropwise condensers are an effective means of heat transfer but widespread use in industry relies on identifying a durable, cost effective dropwise condensation promoter with adequate thermal conductivity. The focus of the work here investigates using rare earth oxides as a possible candidate to address these requirements. A next generation intrachip cooling technology is necessary to overcome the stringent heat dissipation needs of high-heat flux GaN based electronics. A two phase (liquid-tovapor) intrachip cooling technology requires fabrication of a nanoporous membrane with sub 25 nm features for pumping a working fluid within the device. Patterning at these length scales is difficult due to the cost of ownership of state of the art photolithography. The work here aims to develop a high fidelity, low cost block copolymer lithography technique using PS-b-P4VP for large-scale feature definition suitable for patterning. The long anneal times and polymer dewetting issues associated with standard solvent vapour annealing have been addressed in this work by developing a custom-built block copolymer annealing chamber. Finally surface and interface studies were performed on porous low-κ dielectric thin films for use in back end of line microelectronic device fabrication. The continued shrinking of on chip devices has resulted in increased line resistance and parasitic capacitance within the multilevel interconnects leading to delays in signal propagation. Low-κ dielectrics combined with self-forming copper diffusion barrier layers are a promising candidate to alleviate resistance and capacitance within the interconnect structure. The thesis is presented in an article based format, with each chapter comprising a research topic that includes a review of the literature in the introduction of each chapter

Detection of explosives and their degradation products

NRC publication: Ye