Behavioral and fMRI evidence of the differing cognitive load of domain-specific assessments.

Standards-referenced educational reform has increased the prevalence of standardized testing; however, whether these tests accurately measure students' competencies has been questioned. This may be due to domain-specific assessments placing a differing domain-general cognitive load on test-takers. To investigate this possibility, functional magnetic resonance imaging (fMRI) was used to identify and quantify the neural correlates of performance on current, international standardized methods of spelling assessment. Out-of-scanner testing was used to further examine differences in assessment results. Results provide converging evidence that: (a) the spelling assessments differed in the cognitive load placed on test-takers; (b) performance decreased with increasing cognitive load of the assessment; and (c) brain regions associated with working memory were more highly activated during performance of assessments that were higher in cognitive load. These findings suggest that assessment design should optimize the cognitive load placed on test-takers, to ensure students' results are an accurate reflection of their true levels of competency.

Branded food references in children's magazines: 'advertisements' are the tip of the iceberg.

OBJECTIVE: While children's magazines 'blur the lines' between editorial content and advertising, this medium has escaped the calls for government restrictions that are currently associated with food advertisements aired during children's television programming. The aim of this study was to address significant gaps in the evidence base in relation to commercial food messages in children's magazines by systematically investigating the nature and extent of food advertising and promotions over a 12-month period. METHOD: All issues of Australian children's magazines published in the calendar year 2009 were examined for references to foods or beverages. RESULTS: Approximately 16% of the 1678 food references identified were portrayals of branded food products (or food brands). However, only 83 of these 269 were clearly identified as advertisements. Of these 269 branded food references, 86% were for non-core (broadly, less healthy) foods, including all but seven of the advertisements. CONCLUSIONS: It appears that recent reductions in televised promotions for non-core foods, and industry initiatives to reduce the targeting of children, have not carried through to magazine advertising. This study adds to the evidence base that the marketing of unhealthy food to children is widespread, and often covert, and supports public health calls for the strengthening of advertising regulation.

Origins and ecological consequences of pollen specialization among desert bees.

An understanding of the evolutionary origins of insect foraging specialization is often hindered by a poor biogeographical and palaeoecological record. The historical biogeography (20,000 years before present to the present) of the desert-limited plant, creosote bush (Larrea tridentata), is remarkably complete. This history coupled with the distribution pattern of its bee fauna suggests pollen specialization for creosote bush pollen has evolved repeatedly among bees in the Lower Sonoran and Mojave deserts. In these highly xeric, floristically depauperate environments, species of specialist bees surpass generalist bees in diversity, biomass and abundance. The ability of specialist bees to facultatively remain in diapause through resource-poor years and to emerge synchronously with host plant bloom in resource-rich years probably explains their ecological dominance and persistence in these areas. Repeated origins of pollen specialization to one host plant where bloom occurs least predictably is a counter-example to prevailing theories that postulate such traits originate where the plant grows best and blooms most reliably Host-plant synchronization, a paucity of alternative floral hosts, or flowering attributes of creosote bush alone or in concert may account for the diversity of bee specialists that depend on this plant instead of nutritional factors or chemical coevolution between floral rewards and the pollinators they have evolved to attract.