Ethnicity and Health: An Analysis of Physical Health Differences across Twenty-one Ethnocultural Groups in Canada

The study of health differences across a wide-range of ethnic, racial, and cultural groups has received relatively little attention in the literature. Twenty-one ethnocultural groups are examined in the current study, providing one of the most comprehensive analyses to-date on ethnicity and physical health in Canada. Two specific research questions are addressed. First, what is the extent of ethnocultural-based health inequalities in Canada? Second, do ethnocultural differences in health reflect differences in social structural and health-related behavioural environments? These questions are analyzed using the master datafile of the 2000/2001 Canadian Community Health Survey (n=129,588). Three global measures of physical health are used: self-rated health, functional health, and activity restriction. The results show that certain ethnic and cultural groups experience higher health status compared to other ethnocultural groups. Social structural (i.e., socio-demographic and SES factors) and behavioural (alcohol and cigarette consumption, diet/nutrition, and exercise) control variables are also introduced to determine if these factors mediate the relationship between ethnicity/race and health. These findings show that health differences between ethnic and racial groups are partly attributable to structural and behavioural factors. They also show that the mediating effects of these variables vary across ethnocultural groups, and that social structural factors are generally more important than behavioural ones in explaining ethnocultural-based differences in health. The implications of the study findings for future research on ethnicity and health and for health care policies are discussed.ethnicity, race, self-rated health, functional health, social structure, lifestyle

GaAs-based optoelectronic neurons

An integrated, optoelectronic, variable thresholding neuron implemented monolithically in GaAs integrated circuit and exhibiting high differential optical gain and low power consumption is presented. Two alternative embodiments each comprise an LED monolithically integrated with a detector and two transistors. One of the transistors is responsive to a bias voltage applied to its gate for varying the threshold of the neuron. One embodiment is implemented as an LED monolithically integrated with a double heterojunction bipolar phototransistor (detector) and two metal semiconductor field effect transistors (MESFET's) on a single GaAs substrate and another embodiment is implemented as an LED monolithically integrated with three MESFET's (one of which is an optical FET detector) on a single GaAs substrate. The first noted embodiment exhibits a differential optical gain of 6 and an optical switching energy of 10 pJ. The second embodiment has a differential optical gain of 80 and an optical switching energy of 38 pJ. Power consumption is 2.4 and 1.8 mW, respectively. Input 'light' power needed to turn on the LED is 2 micro-W and 54 nW, respectively. In both embodiments the detector is in series with a biasing MESFET and saturates the other MESFET upon detecting light above a threshold level. The saturated MESFET turns on the LED. Voltage applied to the biasing MESFET gate controls the threshold

GaAs optoelectronic neuron arrays

A simple optoelectronic circuit integrated monolithically in GaAs to implement sigmoidal neuron responses is presented. The circuit integrates a light-emitting diode with one or two transistors and one or two photodetectors. The design considerations for building arrays with densities of up to 10^4 cm^-2 are discussed

Comparing Racial and Immigrant Health Status and Health Care Access in Later Life in Canada and the United States

Little comparative research exists on health experiences and conditions of minority groups in Canada and the United States, despite both countries having a racially diverse population with a signifi cant proportion of immigrants. This article explores race and immigrant disparities in health and health care access across the two countries. The study focus was on middle and old age given the change and increasing diversity in health and health care policy, such as Medicare. Logistic regression analysis of data from the 2002–2003 Joint Canada/United States Survey of Health shows that the joint effect of race and nativity on health outcomes – health differences between native and foreign-born Whites and non- Whites – is largely insignifi cant in Canada but considerable in the U.S. Non-White native and foreign-born Americans within both 45-to-64 and 65-and-over age groups experience signifi cant disadvantage in health status and access to care, irrespective of health insurance coverage, demographic, socio-economic, and lifestyle factors.health, obesity, health care, race, immigrant, Canada, United States

Topology optimization of freeform large-area metasurfaces

We demonstrate optimization of optical metasurfaces over $10^5$--$10^6$ degrees of freedom in two and three dimensions, 100--1000+ wavelengths ($\lambda$) in diameter, with 100+ parameters per $\lambda^2$. In particular, we show how topology optimization, with one degree of freedom per high-resolution "pixel," can be extended to large areas with the help of a locally periodic approximation that was previously only used for a few parameters per $\lambda^2$. In this way, we can computationally discover completely unexpected metasurface designs for challenging multi-frequency, multi-angle problems, including designs for fully coupled multi-layer structures with arbitrary per-layer patterns. Unlike typical metasurface designs based on subwavelength unit cells, our approach can discover both sub- and supra-wavelength patterns and can obtain both the near and far fields

Ethnic Differences in Health: Does Immigration Status Matter?

This study examines health differences between first-generation immigrant and Canadian-born persons who share the same the ethnocultural origin, and the extent to which such differences reflect social structural and health-related behavioural contexts. Data from the 2000/2001 Canadian Community Health Survey show that first generation immigrants of Black and French race/ethnicity tend to have better health than their Canadian-born counterparts, while the opposite is true for those of South Asian, Chinese, and south and east European and Jewish origins. West Asians and Arabs and other Asian groups are advantaged in health regardless of country of birth. Health differences between ethnic foreign- and Canadian-born persons generally converge after adjusting for socio-demographic, SES, and lifestyle factors. Implications for health care policy and program development are discussed.self-rated health; functional health; ethnicity; race; immigration