Patterns in reporting and participant inclusion related to race and ethnicity in autism intervention literature: Data from a large-scale systematic review of evidence-based practices

There are marked racial and ethnic disparities in diagnosis and services for individuals on the autism spectrum, yet race and ethnicity are underreported and underexamined in autism research. The current study examines the reporting of race and ethnicity and the inclusion of participants across racial and ethnic groups in studies included in a large-scale systematic review of autism intervention research (1990–2017). Trained research assistants reviewed 1013 articles and extracted data on the reporting of race and ethnicity data and the inclusion of participants from different racial and ethnic categories from each article. Only 25% of the articles reported any data on race and ethnicity and reporting over time has slowly increased across the 28 years of the review. Descriptive statistics suggest that race and ethnicity reporting varied by study design, intervention, and outcomes. In studies with reported data, White participants had the highest rate of participation (64.8%), with a large gap between the next highest rates of participation, which were among Hispanic/Latino (9.4%), Black (7.7%), and Asian (6.4%) participants. The lack of reporting and the limited inclusion of participants across minoritized racial and ethnic groups are concerning and suggest a need to examine practices in autism research from planning to dissemination. Lay Abstract: Researchers who study autism-related interventions do a poor job reporting data related to the race and ethnicity of autistic individuals who participate in their studies, and of those who do report these data, the participants are overwhelmingly White. This is problematic for many reasons, as we know little about how interventions are meeting the needs of culturally and linguistically diverse populations, and we assume that interventions are effective for all when they have been developed and validated primarily with and for White children. This study examined the reporting patterns of autism intervention researchers whose work was included in a large-scale systematic review of the intervention literature published between 1990 and 2017. We found that only 25% of studies (out of 1,013 included in the review) included data related to the race and ethnicity of their participants, with minimal change in reporting patterns across the years. In studies with reported data, White participants had the highest rate of participation, with a large gap between the next highest rates of participation among Hispanic/Latino, Black, and Asian participants. Other race and ethnicity groups had very low representation. This study includes additional analyses which examine how the reporting patterns and the inclusion of racially and ethnically diverse participants varies across study types, interventions, and outcome areas. Reporting this data is merely a starting point to begin to address the many disparities in autism-related healthcare, education, and research practices, and this article includes broader implications and next steps to ensure the field becomes more equitable and inclusive

A link between large mantle melting events and continent growth seen in osmium isotopes

Although Earth's continental crust is thought to have been derived from the mantle, the timing and mode of crust formation have proven to be elusive issues. The area of preserved crust diminishes markedly with age, and this can be interpreted as being the result of either the progressive accumulation of new crust or the tectonic recycling of old crust. However, there is a disproportionate amount of crust of certain ages1, 2, with the main peaks being 1.2, 1.9, 2.7 and 3.3 billion years old; this has led to a third model in which the crust has grown through time in pulses, although peaks in continental crust ages could also record preferential preservation. The ¹⁸⁷Re–¹⁸⁷Os decay system is unique in its ability to track melt depletion events within the mantle and could therefore potentially link the crust and mantle differentiation records. Here we employ a laser ablation technique to analyse large numbers of osmium alloy grains to quantify the distribution of depletion ages in the Earth's upper mantle. Statistical analysis of these data, combined with other samples of the upper mantle, show that depletion ages are not evenly distributed but cluster in distinct periods, around 1.2, 1.9 and 2.7 billion years. These mantle depletion events coincide with peaks in the generation of continental crust and so provide evidence of coupled, global and pulsed mantle–crust differentiation, lending strong support to pulsed models of continental growth by means of large-scale mantle melting events

APPLICATION OF THE Pt-190-Os-186 ISOTOPE SYSTEM TO DATING PLATINUM MINERALIZATION AND OPHIOLITE FORMATION: AN EXAMPLE FROM THE MERATUS MOUNTAINS, BORNEO

The formation age of platinum-group minerals (PGM) in placer deposits has traditionally been difficult to constrain. We have applied the Pt-Os and Re-Os isotope systems to this problem by analyzing a suite of PGM from a placer deposit in southeastern Borneo that are derived, by mechanical processes, from chromitites of the Meratus ophiolite. Published subduction and emplacement ages and biostratigraphy of pelagic sediments of the ophiolite sequence define a minimum age for genesis at a spreading ridge. However, igneous components of the ophiolite have previously been undateable. Alluvial PGM grains (n = 260) from the Pontyn River, which drains the Meratus Mountains, were analyzed by laser ablation-multicollector-inductively-coupled mass spectrometry (LA-MC-ICPMS). Re-Os data do not show any isochronous relationship. Despite a significant range in Os-187/Os-188 (0.122-0.141), Re-187/Os-188 values show a very narrow range (0.000005-0.002980). In contrast, the PGM have a wide range in both Os-186/Os-188 (0.119801-0.120315) and Pt-190/Os-188 (<0.00001.-1.493430), yielding a precise Pt-Os isochron age of 197.8 +/- 8.1 Ma (2 sigma). This age fits well with published age constraints for tins ophiolite and we argue that it dates the crystallization of the PGM. Previous studies have shown that the Pontyn PGM are derived from ophiolitic chromitite; therefore, the PGM Pt-Os isochron age also provides the first absolute age constraint for the genesis of igneous rocks of the Meratus ophiolite. These results highlight the potential of the Pt-Os geochronometer as a tool for dating the crystallization age of PGM found in placer deposits, for dating primary platinum mineralization in general, and for use in ophiolite geochronology

Precise and accurate 186Os/188Os and 187Os/188Os measurements by Multi-Collector PlasmaIonisation Mass Spectrometry, part II: laser ablation and its application to single-grain Pt–Os and Re–Os geochronology

The abundance of platinum group alloy (PGA) grains available from some alluvial deposits combined with their great chemical resistance to conventional acid attack generates the need for an alternative method of obtaining routine, rapid yet precise Os isotopic data. Laser ablation multi-collector ICPMS (LA-MC-ICPMS) is ideally suited for this purpose and has been applied, in a relatively limited extent, to Os-rich samples by previous workers (e.g., Hirata et al., 1998; Walker et al., 2005). The wide variety of PGA minerals yield a broad spectrum of Pt, Re and Os contents which translate into a wide spread in parent-daughter ratios that is attractive for geochronology using the Re-Os and Pt-Os decay schemes. In fact, we show that single grains, consisting of multiple, syngenetic PGE minerals can contain sufficient internal Re, Pt and Os elemental variability that they present an opportunity to obtain isochron ages from two different isotope decay systems. We present a rapid (40 second acquisition time), precise and accurate LA-MC-ICPMS methodology suitable for applying Pt-Os and Re-Os geochronology approaches to single PGA grains, for use in dating chromitite deposits and identifying and dating multiple sources in alluvial PGA deposits. Because of isobaric interferences from Pt, PGA analyses by LA-MC-ICPMS are best corrected for instrumental mass fractionation using the 189Os/188Os ratio. We demonstrate that, within our analytical uncertainties, mass bias effects for Os isotope ratios during LA-MC-ICPMS are similar in nature and magnitude to mass bias variation produced during normal solution mode analysis. Robust elemental interference corrections can be applied for Re and W on the Os mass spectrum and for Os on the Pt mass spectrum, to constrain Pt/Os ratio measurement simultaneously with Os isotope ratio measurement. Accurate and precise geochronology by La-MC-ICPMS can be limited by poorly quantified fractionation of the Manuscript Click here to download Manuscript: Manuscript04-04-07.doc parent/daughter elemental ratio during ablation. Although further work is required to understand the nature and exact extent of inter-element fractionation of the Pt/Os and Re/Os ratios during laser ablation analysis of Pt- and Re-rich PGA grains, our best estimate is that fractionation of the Pt/Os and Re/Os ratios during laser ablation is less than 5-10%. Using this approach we present multi-grain isochrons and single grain internal isochrons for the Re-Os and Pt-Os isotope systems in PGA grains from Lapland. In all cases, the Pt-Os isotope system gives significantly more precise isochrons than the Re-Os system. We interpret this discordance between the two systems as being most likely due to Re disturbance from the PGA grains. We show that a suite of Pt-rich PGA grains from the Central Lapland greenstone belt yields a spectrum of internal Pt-Os isochron ages that coincides well with pulses of formation of chromitite-bearing ophiolitic material within this magmatic terrane and we take this to indicate the record of chromitite formation in different magmatic units. The single-grain Pt-Os and Re-Os geochronology technique shows great promise in the dating of chromitite deposits in ophiolites and in the discrimination of multiple source regions within alluvial PGA deposits

Electroweak measurements in electron–positron collisions at w-boson-pair energies at lep

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