Wages, Skills, and Technology in the United States and Canada

Wages for more- and less-educated workers have followed strikingly different paths in the U.S. and Canada. During the 1980's and 1990's, the ratio of earnings of university graduates to high school graduates increased sharply in the U.S. but fell slightly in Canada. Katz and Murphy (1992) found that for the U.S. a simple supply-demand model fit the pattern of variation in the premium over time. We find that the same model and parameter estimates explain the variation between the U.S. and Canada. In both instances, the relative demand for more-educated labor shifts out at the same, consistent rate. Both over time and between countries, the variation in rate of growth of relative wages can be explained by variation in the relative supply of more-educated workers. Many economists suspect that technological change is causing the steady increases in the relative demand for more-educated labor. If so, these data provide independent evidence on the spatial and temporal variation in the pattern of technological change. Whatever is causing this increased demand for skill, the evidence from Canada suggest that increases in educational attainment and skills can reduce the rate at which relative wages diverge.

β-Secretases, Alzheimer\u27s Disease, and Down Syndrome

Individuals with Down Syndrome (DS), or trisomy 21, develop Alzheimer\u27s disease (AD) pathology by approximately 40 years of age. Chromosome 21 harbors several genes implicated in AD, including the amyloid precursor protein and one homologue of the β-site APP cleaving enzyme, BACE2. Processing of the amyloid precursor protein by β-secretase (BACE) is the rate-limiting step in the production of the pathogenic Aβ peptide. Increased amounts of APP in the DS brain result in increased amounts of Aβ and extracellular plaque formation beginning early in life. BACE dysregulation potentially represents an overlapping biological mechanism with sporadic AD and a common therapeutic target. As the lifespan for those with DS continues to increase, age-related concerns such as obesity, depression, and AD are of growing concern. The ability to prevent or delay the progression of neurodegenerative diseases will promote healthy aging and improve quality of life for those with DS

Revisiting logistical friendliness: perspectives of international freight forwarders

Logistical friendliness (unfriendliness) refers to the ease (difficulty) of arranging international freight operations to/from a particular country. The present paper builds upon previous research by 1) examininglogistical friendliness and unfriendliness as two different constructs (rather than as opposite ends of the same continuum), and 2) linking the delineation of logistically friendly and unfriendly countries with the reasons for friendliness (unfriendliness). The study results could be quite valuable with corporate decisions as to which countries to do business in, as well as with the appropriate organizational strategies for entering the chosen countries

Independent working memory resources for egocentric and allocentric spatial information.

Visuospatial working memory enables us to maintain access to visual information for processing even when a stimulus is no longer present, due to occlusion, our own movements, or transience of the stimulus. Here we show that, when localizing remembered stimuli, the precision of spatial recall does not rely solely on memory for individual stimuli, but additionally depends on the relative distances between stimuli and visual landmarks in the surroundings. Across three separate experiments, we consistently observed a spatially selective improvement in the precision of recall for items located near a persistent landmark. While the results did not require that the landmark be visible throughout the memory delay period, it was essential that it was visible both during encoding and response. We present a simple model that can accurately capture human performance by considering relative (allocentric) spatial information as an independent localization estimate which degrades with distance and is optimally integrated with egocentric spatial information. Critically, allocentric information was encoded without cost to egocentric estimation, demonstrating independent storage of the two sources of information. Finally, when egocentric and allocentric estimates were put in conflict, the model successfully predicted the resulting localization errors. We suggest that the relative distance between stimuli represents an additional, independent spatial cue for memory recall. This cue information is likely to be critical for spatial localization in natural settings which contain an abundance of visual landmarks

β-Secretases, Alzheimer's Disease, and Down Syndrome

Individuals with Down Syndrome (DS), or trisomy 21, develop Alzheimer's disease (AD) pathology by approximately 40 years of age. Chromosome 21 harbors several genes implicated in AD, including the amyloid precursor protein and one homologue of the β-site APP cleaving enzyme, BACE2. Processing of the amyloid precursor protein by β-secretase (BACE) is the rate-limiting step in the production of the pathogenic Aβ peptide. Increased amounts of APP in the DS brain result in increased amounts of Aβ and extracellular plaque formation beginning early in life. BACE dysregulation potentially represents an overlapping biological mechanism with sporadic AD and a common therapeutic target. As the lifespan for those with DS continues to increase, age-related concerns such as obesity, depression, and AD are of growing concern. The ability to prevent or delay the progression of neurodegenerative diseases will promote healthy aging and improve quality of life for those with DS

Examining international freight forwarder services: the perspectives of current providers and users

The service quality literature indicates a variety of gaps between expected and perceived quality, and that service quality is a key determinant of customer satisfaction. As such, the present paper examines international freight forwarders (IFFs) and IFF customers with respect to various services which might be provided by IFFs; the paper also reports on user satisfaction with their IFFs. The study results identified several mismatches between what the forwarders are currently providing and what services the users view as important. In addition, the satisfaction ratings suggest that forwarders’ performance has room for improvement

Some propositions regarding rail-truck intermodal: an empirical analysis

Using data compiled from a recent of businesses located in a major metropolitan area, the present paper evaluates a series of propositions concerning rail-truck intermodal. In general, the study results tend to support the various propositions, and key findings suggest that users and nonusers of intermodal transportation have different perceptions about the quality of, and barriers to, intermodal service