Boundary objects and boundary crossing for numeracy teaching

In this paper, we share analysis of an episode of a pre-service teacher’s handling of a map artefact within his practicum teaching of ‘Mathematical Literacy’ in South Africa. Mathematical Literacy, as a post-compulsory phase subject in the South African curriculum, shares many of the aims of numeracy as described in the international literature— including approaches based on the inclusion of real life contexts and a trajectory geared towards work, life and citizenship. Our attention in this paper is focused specifically on artefacts at the boundary of mathematical and contextual activities. We use analysis of the empirical handling of artefacts cast as ‘boundary objects’ to argue the need for ‘boundary crossing’ between mathematical and contextual activities as a critical feature of numeracy teaching. We pay particular attention to the differing conventions and extents of applicability of rules associated with boundary artefacts when working with mathematical or contextual perspectives. Our findings suggest the need to consider boundary objects more seriously within numeracy teacher education, with specific attention to the ways in which they are configured on both sides of the boundary in order to deal effectively with explanations and interactions in classrooms aiming to promote numeracy

The influence of nativity and neighborhoods on breast cancer stage at diagnosis and survival among California Hispanic women

<p>Abstract</p> <p>Background</p> <p>In the US, foreign-born Hispanics tend to live in socioeconomic conditions typically associated with later stage of breast cancer diagnosis, yet they have lower breast cancer mortality rates than their US-born counterparts. We evaluated the impact of nativity (US- versus foreign-born), neighborhood socioeconomic status (SES) and Hispanic enclave (neighborhoods with high proportions of Hispanics or Hispanic immigrants) on breast cancer stage at diagnosis and survival among Hispanics.</p> <p>Methods</p> <p>We studied 37,695 Hispanic women diagnosed from 1988 to 2005 with invasive breast cancer from the California Cancer Registry. Nativity was based on registry data or, if missing, imputed from case Social Security number. Neighborhood variables were developed from Census data. Stage at diagnosis was analyzed with logistic regression, and survival, based on vital status determined through 2007, was analyzed with Cox proportional hazards regression.</p> <p>Results</p> <p>Compared to US-born Hispanics, foreign-born Hispanics were more likely to be diagnosed at an advanced stage of breast cancer (adjusted odds ratio (OR) = 1.14, 95% confidence interval (CI): 1.09-1.20), but they had a somewhat lower risk of breast cancer specific death (adjusted hazard ratio (HR) = 0.94, 95% CI: 0.90-0.99). Living in low SES and high enclave neighborhoods was associated with advanced stage of diagnosis, while living in a lower SES neighborhood, but not Hispanic enclave, was associated with worse survival.</p> <p>Conclusion</p> <p>Identifying the modifiable factors that facilitate this survival advantage in Hispanic immigrants could help to inform specific interventions to improve survival in this growing population.</p

The Population Decline and Extinction of Darwin's Frogs

Darwin's frogs (Rhinoderma darwinii and R. rufum) are two species of mouth-brooding frogs from Chile and Argentina. Here, we present evidence on the extent of declines, current distribution and conservation status of Rhinoderma spp.; including information on abundance, habitat and threats to extant Darwin's frog populations. All known archived Rhinoderma specimens were examined in museums in North America, Europe and South America. Extensive surveys were carried out throughout the historical ranges of R. rufum and R. darwinii from 2008 to 2012. Literature review and location data of 2,244 archived specimens were used to develop historical distribution maps for Rhinoderma spp. Based on records of sightings, optimal linear estimation was used to estimate whether R. rufum can be considered extinct. No extant R. rufum was found and our modelling inferred that this species became extinct in 1982 (95% CI, 1980-2000). Rhinoderma darwinii was found in 36 sites. All populations were within native forest and abundance was highest in Chiloé Island, when compared with Coast, Andes and South populations. Estimated population size and density (five populations) averaged 33.2 frogs/population (range, 10.2-56.3) and 14.9 frogs/100 m(2) (range, 5.3-74.1), respectively. Our results provide further evidence that R. rufum is extinct and indicate that R. darwinii has declined to a much greater degree than previously recognised. Although this species can still be found across a large part of its historical range, remaining populations are small and severely fragmented. Conservation efforts for R. darwinii should be stepped up and the species re-classified as Endangered

Community Level Correlates of Low Birthweight Among African American, Hispanic and White Women in California

OBJECTIVES: Racial and ethnic groups in the US exhibit major differences in low birthweight (LBW) rates. While previous studies have shown that community level social indicators associated with LBW vary by race and ethnicity, it is not known whether these differences exist among racial or ethnic groups who live in the same neighborhood or community. To address this question, we examined the association of community level features with LBW among African American, White and Hispanic women who live in similar geographic areas. METHODS: The analysis is based on geocoded birth certificates for all singleton live births in the year 2000 to women residing in 805 California ZIP codes. Community level social and demographic data were obtained from U.S. Census data files for the year 2000 and surrogate indices of population level alcohol and drug abuse and dependence were derived from hospital discharge data (HDD). Tobit and bootstrap analyses were used to test associations with birth outcomes, maternal characteristics, and community level social and demographic features within and across the three groups of women living in similar geographic areas. RESULTS: The results demonstrate major racial and ethnic differences in community level correlates of LBW. Rates of LBW among African Americans were lower if they lived in areas that were more densely populated, had greater income disparities, were more racially segregated, and had low rates of alcohol abuse or dependence. These associations were different or absent for Hispanic and White women. CONCLUSIONS FOR PRACTICE: The results suggest that despite living in the same areas, major differences in neighborhood features and social processes are linked to birth outcomes of African American women compared to Hispanic and White women. Further research, especially using multilevel approaches, is needed to precisely identify these differences to help reduce racial and ethnic disparities in LBW

Evidence-based management and intervention for autism spectrum disorders

info:eu-repo/semantics/publishe

Alcohol Outlet Density and Young Women’s Perpetration of Violence Toward Male Intimate Partners

This paper examines the relationships between alcohol outlet density, alcohol use, and perpetration of intimate partner violence (IPV) among young adult women in the US. Data were from Wave III of the National Longitudinal Study of Adolescent Health (Add Health; N = 4,430 in present analyses). Multinomial logistic regression was used to examine occurrence of past year IPV perpetration toward a male partner based on tract-level on-premise and off-premise alcohol outlet density, controlling for individuals’ demographic, alcohol use, and childhood abuse characteristics and neighborhood socio-demographic factors. Higher off-premise alcohol outlet density was found to be associated with young women’s perpetration of physical only IPV, controlling for individual-level and ecological factors. Alcohol use had an independent association with IPV perpetration but was not a mediator of the outlet density-IPV relationship. Findings suggest that considering alcohol-related environmental factors may help efforts aimed at preventing young women’s use of physical violence toward partners