15,637 research outputs found
The Arizona Kith and Kin Project Evaluation, Brief #3
Professional Development with Family, Friend, and Neighbor Providers: Implications for Dual Language Learners. Indigo Cultural Center, for the Association for Supportive Child Care, with support from First Things First and Valley of the Sun United Way
Design, fabrication, and testing of micromachined silicone rubbermembrane valves
Technologies for fabricating silicone rubber membranes and integrating them with other processes on silicon wafers have been developed. Silicone rubber has been found to have exceptional mechanical properties including low modulus, high elongation, and good sealing. Thermopneumatically actuated, normally open, silicone rubber membrane valves with optimized components have been designed, fabricated, and tested. Suspended silicon nitride membrane heaters have been developed for low-power thermopneumatic actuation. Composite silicone rubber on Parylene valve membranes have been shown to have low permeability and modulus. Also, novel valve seats were designed to improve sealing in the presence of particles. The valves have been extensively characterized with respect to power consumption versus flow rate and transient response. Low power consumption, high flow rate, and high pressure have been demonstrated. For example, less than 40 mW is required to switch a 1-slpm nitrogen flow at 33 psi. Water requires dose to 100 mW due to the cooling effect of the liquid
The Arizona Kith and Kin Project Evaluation, Brief #4
Despite the prevalence of family, friend, and neighbor (FFN) child care (NSECE, 2015), relatively little is known about the characteristics of this type of care, quality of care, and the features of effective quality improvement initiatives for FFN care providers. In general, the early childhood field has remained relatively silent about FFN child care in policy and research discourses surrounding child well-being and quality initiatives (Shivers, 2012; Whitebook et al., 2004). The overall goal of the analyses described in this brief, Brief #4 in a series of four, was to explore and analyze FFN providers’ awareness and use of community resources. This sample was obtained by collecting data from providers involved in a 14-week training-support group intervention known as the Arizona Kith and Kin Project. The providers in the Arizona Kith and Kin Project represent a critical population of providers who are serving young children in Arizona
An Empirical Analysis of Liquidity and Order Flow in the Brokered Interdealer Market for Government of Canada Bonds
The authors empirically measure Canadian bond market liquidity using a number of indicators proposed in the literature and detail, for the first time, price and trade dynamics in the Government of Canada secondary bond market. They find, consistent with Inoue (1999), that the Canadian brokered interdealer fixed-income market is relatively liquid for its size. Liquidity measures are analyzed relative to each other and across securities, and intraday patterns are identified. The authors' results show that trading activity is positively correlated with price volatility, and that signed order flow is significant in explaining contemporaneous high-frequency price movements. They find evidence that trading activity is positively related to liquidity measures in some markets, which suggests that indicators such as trade frequency and trading volume, despite certain drawbacks, can be seen as useful proxies for liquidity. The authors also document Canadian participants' prevalent use of an order expansion protocol, whereby order size can be negotiated upward once a trade has been initiated; although Boni and Leach (2002) identify this practice as consistent with a market where there is relatively strong concern regarding information asymmetry, the authors observe no consistent link between the frequency of its use and observations of trading activity, market liquidity, or price volatility.Financial markets; Market structure and pricing
Deep-tissue focal fluorescence imaging with digitally time-reversed ultrasound-encoded light.
Fluorescence imaging is one of the most important research tools in biomedical sciences. However, scattering of light severely impedes imaging of thick biological samples beyond the ballistic regime. Here we directly show focusing and high-resolution fluorescence imaging deep inside biological tissues by digitally time-reversing ultrasound-tagged light with high optical gain (~5×10(5)). We confirm the presence of a time-reversed optical focus along with a diffuse background-a corollary of partial phase conjugation-and develop an approach for dynamic background cancellation. To illustrate the potential of our method, we image complex fluorescent objects and tumour microtissues at an unprecedented depth of 2.5 mm in biological tissues at a lateral resolution of 36 μm×52 μm and an axial resolution of 657 μm. Our results set the stage for a range of deep-tissue imaging applications in biomedical research and medical diagnostics
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