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Purpose: This study collected measures of auditory-perceptual and oral somatosensory acuity in typically developing children and adolescents aged 9–15 years. We aimed to establish reference data that can be used as a point of comparison for individuals with residual speech sound disorder (RSSD), especially for RSSD affecting American English rhotics. We examined concurrent validity between tasks and hypothesized that performance on at least some tasks would show a significant association with age, reflecting ongoing refinement of sensory function in later childhood. We also tested for an inverse relationship between performance on auditory and somatosensory tasks, which would support the hypothesis of a trade-off between sensory domains. Method: Ninety-eight children completed three auditory-perceptual tasks (identification and discrimination of stimuli from a “rake”–“wake” continuum and category goodness judgment for naturally produced words containing rhotics) and three oral somatosensory tasks (bite block with auditory masking, oral stereognosis, and articulatory awareness, which involved explicit judgments of relative tongue position for different speech sounds). Pairwise associations were examined between tasks within each domain and between task performance and age. Composite measures of auditory-perceptual and somatosensory functions were used to investigate the possibility of a sensory trade-off. Results: Statistically significant associations were observed between the identification and discrimination tasks and the bite block and articulatory awareness tasks. In addition, significant associations with age were found for the category goodness and bite block tasks. There was no statistically significant evidence of a trade-off between auditory-perceptual and somatosensory domains. Conclusions: This study provided a multidimensional characterization of speech-related sensory function in older children/adolescents. Complete materials to administer all experimental tasks have been shared, along with measures of central tendency and dispersion for scores in two subgroups of age. Ultimately, we hope to apply this information to make customized treatment recommendations for children with RSSD based on sensory profiles. more...

Current models of second language (L2) acquisition focus on interactions with a first language (L1) at the level of speech sound targets. In multilinguals, the degree of interaction between the articulatory plans that guide speech in each language remains unclear. Here, we directly address this question in bilingual speakers. We use a sensorimotor adaptation paradigm to drive the acquisition of novel articulatory plans for speech in one language and then measure the extent to which these new motor plans influence articulatory plans in the speaker's other language. Twenty L1-French, L2-English bilinguals adapted their speech production to a real-time alteration of vowel sounds. In one session, the adaptation was acquired during French sentence production; in a second session, the adaptation was acquired during English sentence production. In each session, cross-language transfer of these novel articulatory plans for speech was assessed using a transfer task that involved the production of French and English words with heavily noise-masked auditory feedback. Sensorimotor adaptation that countered the vowel sound alteration was observed in both French and English. Regardless of the linguistic context in which the adaptation was acquired, the adaptation transferred to the production of words in both languages. The amount of transfer did not depend on whether the adaptation was acquired in the participant's L1 or L2. In a second experiment, the result was replicated with twenty L1-English, L2-French speakers. The experiments support the idea that, in bilinguals, the interaction between L1 and L2 articulatory motor plans is rapid and bidirectional. more...

Processes controlling dissolved barium (dBa) were investigated along the GEOTRACES GA03 North Atlantic and GP16 Eastern Tropical Pacific transects, which traversed similar physical and biogeochemical provinces. Dissolved Ba concentrations are lowest in surface waters (∼35–50 nmol kg⁻¹) and increase to 70–80 and 140–150 nmol kg⁻¹ in deep waters of the Atlantic and Pacific transects, respectively. Using water mass mixing models, we estimate conservative mixing that accounts for most of dBa variability in both transects. To examine nonconservative processes, particulate excess Ba (pBa_(xs)) formation and dissolution rates were tracked by normalizing particulate excess ²³⁰Th activities. Th-normalized pBa_(xs) fluxes, with barite as the likely phase, have subsurface maxima in the top 1,000 m (∼100–200 μmol m⁻² year⁻¹ average) in both basins. Barite precipitation depletes dBa within oxygen minimum zones from concentrations predicted by water mass mixing, whereas inputs from continental margins, particle dissolution in the water column, and benthic diffusive flux raise dBa above predications. Average pBa_(xs) burial efficiencies along GA03 and GP16 are ∼37% and 17%–100%, respectively, and do not seem to be predicated on barite saturation indices in the overlying water column. Using published values, we reevaluate the global freshwater dBa river input as 6.6 ± 3.9 Gmol year⁻¹. Estuarine mixing processes may add another 3–13 Gmol year⁻¹. Dissolved Ba inputs from broad shallow continental margins, previously unaccounted for in global marine summaries, are substantial (∼17 Gmol year⁻¹), exceeding terrestrial freshwater inputs. Revising river and shelf dBa inputs may help bring the marine Ba isotope budget more into balance. more...

Early studies revealed relationships between barium (Ba), particulate organic carbon and silicate, suggesting applications for Ba as a paleoproductivity tracer and as a tracer of modern ocean circulation. But, what controls the distribution of barium (Ba) in the oceans? Herein, we investigated the Arctic Ocean Ba cycle through a one-of-a-kind data set containing dissolved (dBa), particulate (pBa), and stable isotope Ba ratio (δ138Ba) data from four Arctic GEOTRACES expeditions conducted in 2015. We hypothesized that margins would be a substantial source of Ba to the Arctic Ocean water column. The dBa, pBa, and δ138Ba distributions all suggest significant modification of inflowing Pacific seawater over the shelves, and the dBa mass balance implies that ∼50% of the dBa inventory (upper 500 m of the Arctic water column) was supplied by nonconservative inputs. Calculated areal dBa fluxes are up to 10 µmol m-2 d-1 on the margin, which is comparable to fluxes described in other regions. Applying this approach to dBa data from the 1994 Arctic Ocean Survey yields similar results. The Canadian Arctic Archipelago did not appear to have a similar margin source; rather, the dBa distribution in this section is consistent with mixing of Arctic Ocean-derived waters and Baffin Bay-derived waters. Although we lack enough information to identify the specifics of the shelf sediment Ba source, we suspect that a sedimentary remineralization and terrigenous sources (e.g., submarine groundwater discharge or fluvial particles) are contributors. Plain Language Summary We investigated the barium cycle in the Arctic Ocean. The oceanic barium cycle is supported by the interplay of seawater mixing, river inputs, sediment inputs, and particle formation and export from the water column. We determined that the distribution of dissolved barium in the upper 500 m of the Arctic Ocean is largely set by a shelf sediment source; this is newly described, as previous literature assumed rivers and seawater mixing were the predominant contributors to the distribution. This discovery fits in with recent findings that the shelf sediments are a major source of radium and other trace metals to the surface Arctic Ocean. This is important to consider as the warming climate continues to erode Arctic ice cover (sea ice or glacial). Monitoring the relative sources of Ba to the water column can help define how warming impacts Arctic Ocean biogeochemistry. more...

Introduction/Objective Advances in precision medicine necessitate a closer integration across pathologists, genetic counselors, and other members of the multidisciplinary cancer care team (MDT). Recognizing that physical distancing and fragmented communication may hinder care delivery, the Association of Community Cancer Centers (ACCC) ran a multi-year initiative to explore ways to improve MDT care coordination. Methods/Case Report ACCC held a multistakeholder leadership summit to identify and discuss critical issues regarding biomarker and hereditary genetic testing and the ways in which pathology and genetic counseling professionals interface with the cancer MDT. Through a consensus-driven process, participants identified key opportunities for achieving optimal integration. ACCC also conducted a national survey to explore barriers around biomarker and hereditary genetic testing. Building off these insights, ACCC conducted virtual workshops at three community cancer programs to improve processes around biomarker testing and targeted treatment planning. Results (if a Case Study enter NA) The pathology leadership summit identified the following priorities: 1) streamline and standardize the biomarker test ordering process; 2) improve tissue handling to optimize timely biomarker testing; 3) strengthen communication between pathologists and genetic counselors; 4) empower pathologists with leadership opportunities. In the ACCC survey (n=659), 57% indicated that some or most of their pathologists were generalists. 21% only held one general tumor board. 6% indicated that pathologists often do not attend tumor boards or cancer committee meetings. 64% indicated that pathologists can directly access some or all medical oncology patient records. 67% sent some or most biopsy samples out for biomarker testing. In the ACCC workshops, cancer programs in KS, NC, and NV identified ways to improve the timeliness of genetic counseling referrals and coordinate biomarker testing. Following the workshops, 64% indicated they planned to make moderate or significant changes in their processes. Conclusion Improving collaboration across pathologists, genetic counselors, and the rest of the cancer MDT may lead to more timely and comprehensive biomarker and hereditary genetic testing. These findings may help cancer programs refine processes of care. more...