•Polystyrene nanoparticles (PS NPs) crossed the zebrafish chorion.•PS NPs accumulated in numerous organs during development.•Bradycardia and hypoactivity were observed following exposure to PS NPs.
...Plastic pollution is a critical environmental concern and comprises the majority of anthropogenic debris in the ocean, including macro, micro, and likely nanoscale (less than 100nm in at least one dimension) plastic particles. While the toxicity of macroplastics and microplastics is relatively well studied, the toxicity of nanoplastics is largely uncharacterized. Here, fluorescent polystyrene nanoparticles (PS NPs) were used to investigate the potential toxicity of nanoplastics in developing zebrafish (Danio rerio), as well as to characterize the uptake and distribution of the particles within embryos and larvae. Zebrafish embryos at 6h post-fertilization (hpf) were exposed to PS NPs (0.1, 1, or 10ppm) until 120 hpf. Our results demonstrate that PS NPs accumulated in the yolk sac as early as 24 hpf and migrated to the gastrointestinal tract, gallbladder, liver, pancreas, heart, and brain throughout development (48–120 hpf). Accumulation of PS NPs decreased during the depuration phase (120–168 hpf) in all organs, but at a slower rate in the pancreas and gastrointestinal tract. Notably, exposure to PS NPs did not induce significant mortality, deformities, or changes to mitochondrial bioenergetics, but did decrease the heart rate. Lastly, exposure to PS NPs altered larval behavior as evidenced by swimming hypoactivity in exposed larvae. Taken together, these data suggest that at least some nanoplastics can penetrate the chorion of developing zebrafish, accumulate in the tissues, and affect physiology and behavior, potentially affecting organismal fitness in contaminated aquatic ecosystems.
Many children in need do not receive the psychoeducational evaluation services they need, with an estimated 15% of all students struggling with attentional or learning difficulties that are ...unassessed, and thus unaddressed, during "normal" times. Such evaluations have largely halted during the COVID-19 crisis, with questionable psychometrics of usable measures and clinicians largely unprepared to administer them. Remote, online psychoeducational evaluations have the potential to decrease this access problem by allowing for evaluations to continue during the crisis, as well as redistributing (geographically and potentially socioeconomically) evaluators to populations disproportionately without access. The present study evaluated the equivalence of a remote, online administration procedure for the Wechsler Intelligence Scale for Children, Fifth Edition (WISC-V) with traditional, in-person administration. Results revealed no significant differences-and, therefore, method effects-between the full-scale IQ and index scores between the administration procedures. One subtest did reveal a significant method effect, with children performing more poorly on the remote, online version of the test. Although imperfect, the remote, online procedure is a viable alternative for the traditional, in-person administration of the WISC-V, especially during this time of crisis.
Public Significance Statement
This article evaluates whether the Wechsler Intelligence Scale for Children, Fifth Edition, given in a remote, online format produces equivalent results as the traditional, in-person administration of the test, as it was developed and meant to be used. The findings reveal how evaluators can use the test in a telehealth context, to continue cognitive evaluations during the COVID-19 crisis, as well as ongoing afterward for students without access to evaluation services.
In certain regions of the United States, there has been a dramatic proliferation of trauma centers. The goal of our study was to evaluate transport times during this period of trauma center ...proliferation.
Aggregated data summarizing level I trauma center admissions in Arizona between 2009 and 2018 were provided to our institution by the Arizona Department of Health Services. We evaluated patient demographics, transport times, and injury severity for both rural and urban injuries.
Data included statistics summarizing 266,605 level I trauma admissions in the state of Arizona. The number of state-designated trauma centers during this time increased from 14 to 47, with level I centers increasing from 8 to 13. Slight decreases in mean Injury Severity Score (rural, 9.4 vs. 8.4; urban, 7.9 vs. 7.0) were observed over this period. Median transport time for cases transported from the injury scene directly to a level I center remained stable in urban areas at 0.9 hours in both 2009 and 2018. In rural areas, transport times for these cases were approximately double but also stable, with median times of 1.8 and 1.9 hours. Transport times for cases requiring interfacility transfer before admission at a level I center increased by 0.3 hours for urban injuries (5.3-5.6 hours) and 0.9 hours for rural injuries (5.6-6.5 hours).
Despite the threefold increase in the number of state-designated trauma centers, transport time has not decreased in urban or rural areas. This finding highlights the need for regulatory oversight regarding the number and geographic placement of state-designated trauma centers.
Care management, level IV, Epidemiological, level III.
Visuomotor adaptation has been thought to be an implicit process that results when a sensory-prediction error signal is used to update a forward model. A striking feature of human competence is the ...ability to receive verbal instructions and employ strategies to solve tasks; such explicit processes could be used during visuomotor adaptation. Here, we used a novel task design that allowed us to obtain continuous verbal reports of aiming direction while participants learned a visuomotor rotation. We had two main hypotheses: the contribution of explicit learning would be modulated by instruction and the contribution of implicit learning would be modulated by the form of error feedback. By directly assaying aiming direction, we could identify the time course of the explicit component and, via subtraction, isolate the implicit component of learning. There were marked differences in the time courses of explicit and implicit contributions to learning. Explicit learning, driven by target error, was achieved by initially large then smaller explorations of aiming direction biased toward the correct solution. In contrast, implicit learning, driven by a sensory-prediction error, was slow and monotonic. Continuous error feedback reduced the amplitude of explicit learning and increased the contribution of implicit learning. The presence of instruction slightly increased the rate of initial learning and only had a subtle effect on implicit learning. We conclude that visuomotor adaptation, even in the absence of instruction, results from the interplay between explicit learning driven by target error and implicit learning of a forward model driven by prediction error.
The extent to which two measures of epistemic curiosity (EC), the Epistemic Curiosity Scale (ECS;
Litman & Spielberger, 2003) and the curiosity as a Feeling-of-Deprivation Scale (CFDS;
Litman & ...Jimerson, 2004), differentiated between interest (I) and deprivation (D) type curiosity was examined in four studies. In studies 1 (
N
=
725) and 2 (
N
=
658), exploratory factor analyses of the ECS and CFDS subscales yielded two factors; the first (I-type) involved pleasure associated with discovering new ideas, while the second (D-type) emphasized spending time and effort to acquire a specific answer or solution. In study 3 (
N
=
762), confirmatory factor analysis demonstrated that a 2-factor model comprised of the I- and D-type curiosity items identified in study 2 had the best fit. In study 4 (
N
=
515), correlations between revised I- and D-type measures and different learning goals were evaluated. As hypothesized, the I-EC scale correlated with mastery-oriented learning, whereas the D-EC scale was related to failure-avoidance and success-orientation. The results suggest that I-EC is concerned with stimulating positive affect, diversive exploration, learning something completely new and mastery-oriented learning; D-EC involves the reduction of uncertainty, specific exploration, acquiring information that is missing from an existing knowledge-set and performance-oriented learning.
Computations underlying cognitive strategies in human motor learning are poorly understood. Here we investigate such strategies in a common sensorimotor transformation task. We show that strategies ...assume two forms, likely reflecting distinct working memory representations: discrete caching of stimulus-response contingencies, and time-consuming parametric computations. Reaction times and errors suggest that both strategies are employed during learning, and trade off based on task complexity. Experiments using pressured preparation time further support dissociable strategies: In response caching, time pressure elicits multi-modal distributions of movements; during parametric computations, time pressure elicits a shifting distribution of movements between visual targets and distal goals, consistent with analog re-computing of a movement plan. A generalization experiment reveals that discrete and parametric strategies produce, respectively, more localized or more global transfer effects. These results describe how qualitatively distinct cognitive representations are leveraged for motor learning and produce downstream consequences for behavioral flexibility.
There is mounting evidence for the idea that performance in a visuomotor rotation task can be supported by both implicit and explicit forms of learning. The implicit component of learning has been ...well characterized in previous experiments and is thought to arise from the adaptation of an internal model driven by sensorimotor prediction errors. However, the role of explicit learning is less clear, and previous investigations aimed at characterizing the explicit component have relied on indirect measures such as dual-task manipulations, posttests, and descriptive computational models. To address this problem, we developed a new method for directly assaying explicit learning by having participants verbally report their intended aiming direction on each trial. While our previous research employing this method has demonstrated the possibility of measuring explicit learning over the course of training, it was only tested over a limited scope of manipulations common to visuomotor rotation tasks. In the present study, we sought to better characterize explicit and implicit learning over a wider range of task conditions. We tested how explicit and implicit learning change as a function of the specific visual landmarks used to probe explicit learning, the number of training targets, and the size of the rotation. We found that explicit learning was remarkably flexible, responding appropriately to task demands. In contrast, implicit learning was strikingly rigid, with each task condition producing a similar degree of implicit learning. These results suggest that explicit learning is a fundamental component of motor learning and has been overlooked or conflated in previous visuomotor tasks.
As human cases of tick-borne disease continue to increase, there is a heightened imperative to collect data on human-tick encounters to inform disease prevention. Passive tick surveillance programs ...that encourage members of the public to submit ticks they have encountered can provide a relatively low-cost means of collecting such data. We report the results of 11 years of tick submissions (2006-2016) collected in Monmouth County, New Jersey, an Atlantic coastal county long endemic for Lyme disease. A total of 8,608 ticks acquired in 22 U.S. states were submitted, 89.7% of which were acquired in Monmouth County, from 52 of the County's 53 municipalities. Seasonal submission rates reflected known phenology of common human-biting ticks, but annual submissions of both Amblyomma americanum and Dermacentor variabilis increased significantly over time while numbers of Ixodes scapularis remained static. By 2016, A. americanum had expanded northward in the county and now accounted for nearly half (48.1%) of submissions, far outpacing encounters with I. scapularis (28.2% of submissions). Across all tick species and stages the greatest number of ticks were removed from children (ages 0-9, 40.8%) and older adults (ages 50+, 23.8%) and these age groups were also more likely to submit partially or fully engorged ticks, suggesting increased risk of tick-borne disease transmission to these vulnerable age groups. Significantly more people (43.2%) reported acquiring ticks at their place of residence than in a park or natural area (17.9%). This pattern was more pronounced for residents over 60 years of age (72.7% acquired at home). Education that stresses frequent tick checks should target older age groups engaged in activity around the home. Our results strongly suggest that encounter rates with ticks other than I. scapularis are substantial and increasing and that their role in causing human illness should be carefully investigated.
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