York University

About: York University is a education organization based out in Toronto, Ontario, Canada. It is known for research contribution in the topics: Population & Politics. The organization has 18899 authors who have published 43357 publications receiving 1568560 citations.

Attention and inhibition in bilingual children: evidence from the dimensional change card sort task

Abstract: In a previous study, a bilingual advantage for preschool children in solving the dimensional change card sort task was attributed to superiority in inhibition of attention (Bialystok, 1999). However, the task includes difficult representational demands to encode and interpret the task stimuli, and bilinguals may also have profited from superior representational abilities. This possibility is examined in three studies. In Study 1, bilinguals outperformed monolinguals on versions of the problem containing moderate representational demands but not on a more demanding condition. Studies 2 and 3 demonstrated that bilingual children were more skilled than monolinguals when the target dimensions were perceptual features of the stimulus and that the two groups were equivalent when the target dimensions were semantic features. The conclusions are that bilinguals have better inhibitory control for ignoring perceptual information than monolinguals do but are not more skilled in representation, confirming the results of the original study. The results also identify the ability to ignore an obsolete display feature as the critical difficulty in solving this task.

Bilingualism: The good, the bad, and the indifferent*

Abstract: The present paper summarizes research showing that bilingualism affects linguistic and cognitive performance across the lifespan. The effect on linguistic performance is generally seen as a deficit in which bilingual children control a smaller vocabulary than their monolingual peers and bilingual adults perform more poorly on rapid lexical retrieval tasks. The effect on cognitive performance is to enhance executive functioning and to protect against the decline of executive control in aging. These effects interact to produce a complex pattern regarding the effect of bilingualism on memory performance. Memory tasks based primarily on verbal recall are performed more poorly by bilinguals but memory tasks based primarily on executive control are performed better by bilinguals. Speculations regarding the mechanism responsible for these effects are described.

The embodiment of inequity: health disparities in aboriginal Canada.

Abstract: Health disparities are, first and foremost, those indicators of a relative disproportionate burden of disease on a particular population. Health inequities point to the underlying causes of the disparities, many if not most of which sit largely outside of the typically constituted domain of “health”. The literature reviewed for this synthesis document indicates that time and again health disparities are directly and indirectly associated with social, economic, cultural and political inequities; the end result of which is a disproportionate burden of ill health and social suffering upon the Aboriginal populations of Canada. In analyses of health disparities, it is as important to navigate the interstices between the person and the wider social and historical contexts as it is to pay attention to the individual effects of inequity. Research and policy must address the contemporary realities of Aboriginal health and well-being, including the individual and community-based effects of health disparities and the direct and indirect sources of those disparities.

The Model-Free Implied Volatility and Its Information Content

Abstract: Britten-Jones and Neuberger (2000) derived a model-free implied volatility under the diffusion assumption. In this article, we extend their model-free implied volatility to asset price processes with jumps and develop a simple method for implementing it using observed option prices. In addition, we perform a direct test of the informational efficiency of the option market using the model-free implied volatility. Our results from the Standard & Poor’s 500 index (SPX) options suggest that the model-free implied volatility subsumes all information contained in the Black-Scholes (B-S) implied volatility and past realized volatility and is a more efficient forecast for future realized volatility.

Rapid and highly variable warming of lake surface waters around the globe

Abstract: In this first worldwide synthesis of in situ and satellite-derived lake data, we find that lake summer surface water temperatures rose rapidly (global mean = 0.34°C decade−1) between 1985 and 2009. Our analyses show that surface water warming rates are dependent on combinations of climate and local characteristics, rather than just lake location, leading to the counterintuitive result that regional consistency in lake warming is the exception, rather than the rule. The most rapidly warming lakes are widely geographically distributed, and their warming is associated with interactions among different climatic factors—from seasonally ice-covered lakes in areas where temperature and solar radiation are increasing while cloud cover is diminishing (0.72°C decade−1) to ice-free lakes experiencing increases in air temperature and solar radiation (0.53°C decade−1). The pervasive and rapid warming observed here signals the urgent need to incorporate climate impacts into vulnerability assessments and adaptation efforts for lakes.