41,183 research outputs found
Thrust reverser for a long duct fan engine
A bypass duct outer cowl includes a fixed cascade disposed between axially spaced fixed cowl portions and a translatable cowl sleeve and blocker doors movably disposed on the respective radially outer and inner sides of the cascade. Actuation and linkage structure located entirely within the outer cowl provides for selectively moving the cowl sleeve rearwardly and rotating the blocker doors to a position across the bypass duct to cause the fan airflow to pass through the cascade in a thrust reversing manner
Predicting Treatment Success in Child and Parent Therapy Among Families in Poverty
Behavior problems are prevalent in young children and those living in poverty are at increased risk for stable, high-intensity behavioral problems. Research has demonstrated that participation in child and parent therapy (CPT) programs significantly reduces problematic child behaviors while increasing positive behaviors. However, CPT programs, particularly those implemented with low-income populations, frequently report high rates of attrition (over 50%). Parental attributional style has shown some promise as a contributing factor to treatment attendance and termination in previous research. The authors examined if parental attributional style could predict treatment success in a CPT program, specifically targeting low-income urban children with behavior problems. A hierarchical logistic regression was used with a sample of 425 families to assess if parent- and child-referent attributions variables predicted treatment success over and above demographic variables and symptom severity. Parent-referent attributions, child-referent attributions, and child symptom severity were found to be significant predictors of treatment success. Results indicated that caregivers who viewed themselves as a contributing factor for their child\u27s behavior problems were significantly more likely to demonstrate treatment success. Alternatively, caregivers who viewed their child as more responsible for their own behavior problems were less likely to demonstrate treatment success. Additionally, more severe behavior problems were also predictive of treatment success. Clinical and research implications of these results are discussed
Contamination control concepts for space station customer servicing
The customer servicing operations envisioned for the space station, which include instrument repair, orbital replacement unit (ORU) changeout, and fluid replenishment for free-flying and attached payloads, are expected to create requirements for a unique contamination control subsystem for the customer servicing facility (CSF). Both the core space station and the CSF users present unique requirements/sensitivities, not all of which are currently defined with common criteria. Preliminary results from an assessment of the effects of the CSF-induced contamination environment are reported. Strategies for a comprehensive contamination control approach and a description of specific hardware devices and their applicability are discussed
Linear Self-Motion Cues Support the Spatial Distribution and Stability of Hippocampal Place Cells
The vestibular system provides a crucial component of place-cell and head-direction cell activity [1-7]. Otolith signals are necessary for head-direction signal stability and associated behavior [8, 9], and the head-direction signal's contribution to parahippocampal spatial representations [10-14] suggests that place cells may also require otolithic information. Here, we demonstrate that self-movement information from the otolith organs is necessary for the development of stable place fields within and across sessions. Place cells in otoconia-deficient tilted mice showed reduced spatial coherence and formed place fields that were located closer to environmental boundaries, relative to those of control mice. These differences reveal an important otolithic contribution to place-cell functioning and provide insight into the cognitive deficits associated with otolith dysfunction
Capital Flows and Destabilizing Policy in Latin America
Motivated by the excessive macroeconomic volatility experienced in Latin America, we examine the possible contribution of monetary and fiscal policies to this outcome. In contrast with previous literature, we consider the possible simultaneity between policy and GDP growth by using GMM VAR econometric techniques. Additionally, we explore the direct impact international capital inflows have on these policies. Our evidence suggests that for the group of countries we consider, most practice destabilizing fiscal and monetary policy, and capital inflow consistently influences policy in a pro-cyclical direction.Fiscal and Monetary Policies, Capital Flows, Latin America
Finance and the Business Cycle: a Kalman Filter Approach with Markov Switching
This paper combines two popular econometric tools, the dynamic factor model and the Markov-Switching model, to consider three segments of the financial system- the stock market, debt, and money- and their contribution to US business cycles over the past four decades. The dynamic factor model identifies a composite factor index for each financial segment, and using Markov-switching models by Hamilton (1989) and Filardo (1994), this paper then estimates the effect of each segment index on business cycle behaviour. This reexamination of the finance-business cycle link provides results that prove strongest for the effect of stock market movements on business cycles.
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