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The subsurface oceans of icy moons in the outer solar system are prime candidates for harboring extra-terrestrial life. Missions to melt through the ice shells of these worlds utilizing an ice probe or "cryobot" to access the oceans have been proposed. To design such a cryobot for a successful mission, the relationship between a cryobot's heat budget and descent speed within any given environment must be understood. Large uncertainties in the ice shell thickness and temperature profile require that the problem be treated via probabilistic techniques, such as a Monte Carlo simulation. By contrast, the speed of a cryobot descending through ice with specified far-field temperature and material properties can, in principle, be quantified with little uncertainty. A model of cryobot performance that can be computed quickly and accurately will save significant computational time for the broader simulation, and allow for the mission's basic thermal needs to be understood. The work reported here builds upon an existing analytic thermal model of ice probes that, while suitable for terrestrial conditions, begins to incur potentially problematic errors in extraterrestrial environments. The new model provides improvement to the previous model for flight-relevant probes in extra-terrestrial ice conditions, predicting the total heat budget to within 1.2% of high-fidelity numerical simulations while requiring a small fraction of the computational time. The model can be non-dimensionalized in a compact form, making it suitable for modeling a broad class of cylindrical ice probes in a probabilistic modeling framework for determining the time required to access the sub-surface ocean. Such models can then provide the high-level requirements for cryobot system architectures that will enable successful ocean-access missions. [Display omitted] • Responds to strong community interest in accessing the oceans of Europa and Enceladus. • Quick-solving quasi-analytic model relates ice probe descent speed to heat budget. • Builds upon previous work to include temperature dependence and a water annulus. • Verified with benchmark high-fidelity numerical cases. • Provides a powerful tool for high-level mission design for accessing sub-surface ocean worlds. [ABSTRACT FROM AUTHOR]

Substantial progress has been made in understanding the neurocognitive underpinnings of learning math. Building on this work, it has been hypothesized that declarative and procedural memory, two domain-general learning and memory systems, play important roles in acquiring math skills. In a longitudinal study, we tested whether in fact declarative and procedural memory predict children's math skills during elementary school years. A sample of 109 children was tested across grades 2, 3 and 4. Linear mixed-effects regression and structural equation modeling revealed the following. First, learning in declarative but not procedural memory was associated with math skills within each grade. Second, declarative but not procedural memory in each grade was related to math skills in all later grades (e.g., declarative memory in grade 2 was related to math skills in grade 4). Sensitivity analyses showed that the pattern of results was robust, except for the longitudinal prediction of later math skills when accounting for stable inter-individual differences via the inclusion of random intercepts. Our findings highlight the foundational role of early domain-general learning and memory in children's acquisition of math. [ABSTRACT FROM AUTHOR]

Processing action words (e.g., fork, throw) engages neurocognitive motor representations, consistent with embodied cognition principles. Despite age-related neurocognitive changes that could affect action words, and a rapidly aging population, the impact of healthy aging on action-word processing is poorly understood. Previous research suggests that in lexical tasks demanding semantic access, such as picture naming, higher motor-relatedness can enhance performance (e.g., fork vs. pier)—particularly in older adults, perhaps due to the age-related relative sparing of motor-semantic circuitry, which can support action words. However, motor-relatedness was recently found to affect performance in younger but not older adults in lexical decision. We hypothesized this was due to decreased semantic access in this task, especially in older adults. Here we tested effects of motor-relatedness on 2,174 words in younger and older adults not only in lexical decision but also in reading aloud, in which semantic access is minimal. Mixed-effects regression, controlling for phonological, lexical, and semantic variables, yielded results consistent with our predictions. In lexical decision, younger adults were faster and more accurate at words with higher-motor relatedness, whereas older adults showed no motor-relatedness effects. In reading aloud, neither age group showed such effects. Multiple sensitivity analyses demonstrated that the patterns were robust. Altogether, whereas previous research indicates that in lexical tasks demanding semantic access, higher motor-relatedness can enhance performance, especially in older adults, evidence now suggests that such effects are attenuated with decreased semantic access, which in turn depends on the task as well as aging itself. Public Significance Statement: Action words (such as fork or throw) can be processed faster and more accurately than nonaction words (such as pier or think), but this effect depends on the task and one's age. [ABSTRACT FROM AUTHOR]

Cunnings (Cunnings) offers an interpretation of L2-L1 sentence processing differences in terms of memory principles. We applaud such cross-domain approaches, which seem likely to significantly elucidate the neurocognition of language. Cunnings attributes sentence processing differences between (adult) high proficiency L2 and L1 speakers to an increased susceptibility to similarity-based retrieval interference, rather than to qualitative L2-L1 processing differences (cf. Clahsen & Felser, 2006). On his account, both L1 and L2 sentence processing depend upon a ‘bipartite’ working memory, which involves maintaining items active by focusing attention on long-term memory representations (Cowan, 2001). [ABSTRACT FROM AUTHOR]