History of a Problem Solving Course for Pre-Service K-8 Teachers

James Madison University\u27s mathematics course in problem solving for prospective K-8 teachers has gone through many changes since we introduced it as a course for prospective middle school teachers four years ago. This paper will discuss the original design of the course, the changes made and their reasons, and the current state of the course

National Accounts for a Global Economy: the Case of Ireland. Quarterly Economic Commentary Special Article, Summer 2018

Globalisation is affecting the way economic activity is reflected in the National Accounts. Intellectual property, which is now part of the capital stock, interacts with the choice of global firms as to their legal structure, producing different national accounting outcomes for individual countries. This is but one manifestation of the challenges that a global economy presents for national accounting. Using the example of Ireland, consideration is given to the data needed to meet the needs of users of National Accounts. In particular, more information is required to separately identify all the activity of multinational enterprises and domestically owned firms. This paper suggests a set of satellite accounts for Ireland that would show how changes in the economy affect the economic welfare of Irish residents

Bonding with Self-Etching Primers - Pumice or Pre-Etch? An In Vitro Study

The objective of this study was to compare the shear bond strengths (SBS) of orthodontic brackets bonded with self-etching primer using different enamel surface preparations. A 2-by-2 factorial study design was used. Sixty human premolars were harvested, cleaned and randomly assigned to four groups (n=15/group). Teeth were bathed in saliva for 48 hours to form a pellicle. Treatments were assigned as follows: Group 1 was pumiced for 10 seconds and pre-etched for five seconds with 37% phosphoric acid before bonding with self-etching primer (Transbond Plus). Group 2 was pumiced for ten seconds before bonding. Group 3 was pre-etched for five seconds before bonding. Group 4 had no mechanical or chemical preparation before bonding. All teeth were stored in distilled water for 24 hours at 37oC before debonding. The SBS values and Adhesive Remnant Index (ARI) score were recorded. Scanning electron microscopy (SEM) was used to investigate the enamel changes at each stage of surface preparation and bonding. The SBS values (±1 SD) for Groups 1-4 were 22.9±6.1, 16.1±7.3, 36.2 ±8.2, and 13.1±10.1 MPa, respectively. Two-way ANOVA and subsequent contrasts showed statistically significant differences among treatment groups. ARI scores indicated the majority of adhesive remained on the bracket for all 4 groups. SEM micrographs showed variable enamel surface roughness depending upon preparation. In conclusion, pre-etching the bonding surface for five seconds with 37% phosphoric acid, instead of pumicing, when using self-etching primers to bond orthodontic brackets, results in greater shear bond strengths

Cine recording ophthalmoscope

Camera system provides accurate photographic recording during acceleration of centrifuge and permits immediate observation of dynamic changes in retinal circulation by a closed-circuit television loop. System consists of main camera, remote control unit, and strobe power supply unit, and is used for fluorescein studies and dynamometry sequences

A hazard model for welfare durations with unobserved location-specific effects

Many papers have investigated how personal characteristics and environmental variables affect welfare durations of unmarried mothers. This paper estimates proportional hazard models for welfare durations that allow for either fixed state or fixed labor market area effects. Conditioning on residence location by fixed effects can limit the impact of three types of potential bias. (1) Estimates of the effects of personal characteristics can be biased owing to the omission of relevant local area variables. (2) Estimates of the impact of state welfare benefit levels are biased because they proxy for other unmeasured attributes of the state, in particular, the entire state welfare system. Conditioning on state fixed effects limits this bias to the extent that we can use time variation within states to estimate the benefit level effect. (3) With state fixed effects, we can better estimate the impact of local conditions, such as unemployment rates, because they also may have been picking up omitted state-level effects. The models are estimated by the Cox partial likelihood method with time-varying covariates. Data come from the 1984 and 1985 panels of the Survey of Income and Program Participation. I find that some personal characteristics (being black or Hispanic, education) have greater impact after controlling for location-specific effects.

Work schedules, wages, and employment in a general equilibrium model with team production

An analysis of working hours, wages, and employment when production requires coordinating the work schedules of heterogeneous workers. The author shows that this coordination aspect of production can have important policy implications.Hours of labor ; Employment (Economic theory) ; Wages

Inventories and the business cycle: an overview

A review of research on the relationship between inventory investment and business cycle fluctuations, focusing on the developments of the last 15 years. A central issue in the literature, the relative importance of demand and supply shocks as sources of fluctuations, continues to be debated.Inventories ; Business cycles

An introduction to the search theory of unemployment

The author presents a model of job search that focuses on an unemployed person's decision to accept an offered job or to continue looking for a new one.Unemployment

Money growth and inflation: how long is the long run?

In their efforts to maintain low inflation, policymakers pay little attention to the growth rate of the money supply. Yet many studies have found that money growth and inflation a closely related, at least in the long run. But how long must money growth remain strong before it begins to concern policymakers? That is, what is the shortest period over which money growth seems to be reliably associated with inflation?Inflation (Finance) ; Money supply ; Monetary policy

Inflation and monetary policy in the twentieth century

This article characterizes the change in the nature of the money growth-inflation and unemployment-inflation relationships between the first and second halves of the twentieth century. The changes are substantial, and the authors discuss some of the implications for modeling inflation dynamics, notably for models of inflation that say that bad inflation outcomes result from poorly designed monetary policy institutions.Inflation (Finance) ; Monetary policy ; Unemployment