9,448 research outputs found

    Labor Market Shocks and Retirement: Do Government Programs Matter?

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    This paper examines how unemployment affects retirement and whether the Unemployment Insurance (UI) system and Social Security (SS) system affect how older workers respond to labor market shocks. To do so, we use pooled cross-sectional data from the March Current Population Survey (CPS) as well as March CPS files matched between one year and the next and longitudinal data from the Health and Retirement Survey (HRS). We find that downturns in the labor market increase retirement transitions. The magnitude of this effect is comparable to that associated with moderate changes in financial incentives to retire and to the threat of a health shock to which older workers are exposed. Interestingly, retirements only increase in response to an economic downturn once workers become SS-eligible, suggesting that retirement benefits may help alleviate the income loss associated with a weak labor market. We also estimate the impact of UI generosity on retirement and find little consistent evidence of an effect. This suggests that in some ways SS may serve as a more effective form of unemployment insurance for older workers than UI.

    Radiation heating in selected NERVA engine components

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    The role of heating from nuclear radiation in design of the NERVA engine is treated. Some components are subjected to very high gamma heating rates in excess of 0.5 Btu/cubic inch/sec in steel in the primary nozzle or 0.25 Btu/cubic inch/sec in aluminum in the pressure vessel. These components must be cooled by a fraction of the liquid hydrogen propellant before it is passed through the core, heated, and expanded out the nozzle as a gas. Other components that are subjected to lower heating rates such as the thrust structure and the disk shield are designed so that they would not require liquid hydrogen cooling. Typical gamma and neutron heating rates, resulting temperatures, and their design consequences are discussed. Calculational techniques used in the nuclear and thermal analyses of the NERVA engine are briefly treated

    Costs and Benefits of Full Dual-Frame Telephone Survey Designs

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    Assesses the cost, sample composition, weighting, and substantive effect on survey results involved in interviewing respondents by cell phone, including those with landlines. Includes demographic profiles of cell phone-only, landline-only, and dual users

    GM1 Ganglioside Modifies α-Synuclein Toxicity and is Neuroprotective in a Rat α-Synuclein Model of Parkinson\u27s Disease.

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    While GM1 may interact with α-synuclein in vitro to inhibit aggregation, the ability of GM1 to protect against α-synuclein toxicity in vivo has not been investigated. We used targeted adeno-associated viral vector (AAV) overexpression of human mutant α-synuclein (A53T) in the rat substantia nigra (SN) to produce degeneration of SN dopamine neurons, loss of striatal dopamine levels, and behavioral impairment. Some animals received daily GM1 ganglioside administration for 6 weeks, beginning 24 hours after AAV-A53T administration or delayed start GM1 administration for 5 weeks beginning 3 weeks after AAV-A53T administration. Both types of GM1 administration protected against loss of SN dopamine neurons and striatal dopamine levels, reduced α-synuclein aggregation, and delayed start administration of GM1 reversed early appearing behavioral deficits. These results extend prior positive results in MPTP models, are consistent with the results of a small clinical study of GM1 in PD patients that showed slowing of symptom progression with chronic use, and argue for the continued refinement and development of GM1 as a potential disease modifying therapy for PD

    Edaq530: a transparent, open-end and open-source measurement solution in natural science education

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    We present Edaq530, a low-cost, compact and easy-to-use digital measurement solution consisting of a thumb-sized USB-to-sensor interface and a measurement software. The solution is fully open-source, our aim being to provide a viable alternative to professional solutions. Our main focus in designing Edaq530 has been versatility and transparency. In this paper, we shall introduce the capabilities of Edaq530, complement it by showing a few sample experiments, and discuss the feedback we have received in the course of a teacher training workshop in which the participants received personal copies of Edaq530 and later made reports on how they could utilise Edaq530 in their teaching

    Interactive manipulation of microparticles in an octagonal sonotweezer

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    An ultrasonic device for micro-patterning and precision manipulation of micrometre-scale particles is demonstrated. The device is formed using eight piezoelectric transducers shaped into an octagonal cavity. By exciting combinations of transducers simultaneously, with a controlled phase delay between them, different acoustic landscapes can be created, patterning micro-particles into lines, squares, and more complex shapes. When operated with all eight transducers the device can, with appropriate phase control, manipulate the two dimensional acoustic pressure gradient; it thus has the ability to position and translate a single tweezing zone to different locations on a surface in a precise and programmable manner
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