This proof-of-concept, double-blind study is designed to determine the effects of transcranial direct current stimulation (tDCS) on the “cost” of performing a secondary cognitive task on gait and postural control in healthy young adults. Twenty adults aged 22±2yrs completed two separate double-blind visits in which gait and postural control were assessed immediately before and after a 20-minute session of either real or sham tDCS (1.5 mA) targeting the left dorsolateral prefrontal cortex. Gait speed and stride duration variability, along with standing postural sway speed and area, were recorded under normal conditions and while simultaneously performing a serial-subtraction cognitive task. Dual task cost was calculated as the percent change in each outcome from normal to dual task conditions. tDCS was well-tolerated by all subjects. Stimulation did not alter gait or postural control under normal conditions. As compared to sham stimulation, real tDCS led to increased gait speed (p=0.006), as well as decreased standing postural sway speed (p=0.01) and area (p=0.01), when performing serial-subtraction task. Real tDCS also diminished (p<0.01) the dual task cost on each of these outcomes. No effects of tDCS were observed for stride duration variability. A single session of tDCS targeting the left dorsolateral prefrontal cortex improved the ability to adapt one’s gait and postural control to a concurrent cognitive task and reduced the cost normally associated with such dual tasking. These results highlight the involvement of cortical brain networks in gait and posture control, and implicate the modulation of prefrontal cortical excitability as a potential therapeutic intervention.

Dual tasking (e.g., walking or standing while performing a cognitive task) disrupts performance in one or both tasks, and such dual-task costs increase with aging into senescence. Dual tasking activates a network of brain regions including pFC. We therefore hypothesized that facilitation of prefrontal cortical activity via transcranial direct current stimulation (tDCS) would reduce dual-task costs in older adults. Thirty-seven healthy older adults completed two visits during which dual tasking was assessed before and after 20 min of real or sham tDCS targeting the left pFC. Trials of single-task standing, walking, and verbalized serial subtractions were completed, along with dual-task trials of standing or walking while performing serial subtractions. Dual-task costs were calculated as the percent change in markers of gait and postural control and serial subtraction performance, from single to dual tasking. Significant dual-task costs to standing, walking, and serial subtraction performance were observed before tDCS (p < .01). These dual-task costs were less after real tDCS as compared with sham tDCS as well as compared with either pre-tDCS condition (p < .03). Further analyses indicated that tDCS did not alter single task performance but instead improved performance solely within dual-task conditions (p < .02). These results demonstrate that dual tasking can be improved by modulating prefrontal activity, thus indicating that dual-task decrements are modifiable and may not necessarily reflect an obligatory consequence of aging. Moreover, tDCS may ultimately serve as a novel approach to preserving dual-task capacity into senescence.

Objective: The aim of this prospective study was to investigate the relationships between inflammation, cerebral vasoregulation, and cognitive decline in type 2 diabetes mellitus (T2DM) over a 2-year span.Methods: Sixty-five participants (aged 66 6 9.2 years, 35 with T2DM, 33 women) were enrolled for this 2-year prospective study. Continuous arterial spin labeling at 3-tesla MRI was used to measure global and regional cerebral perfusion and vasoreactivity. Neuropsychological measures were evaluated at the beginning and completion of the study. The associations between serum inflammatory markers, regional cerebral vasoreactivity, and cognitive functions were examined using least squares models.Results: After 2 years of follow-up, participants with T2DM had diminished global and regional cerebral vasoreactivity and a decline in multiple cognitive tasks compared with baseline (p , 0.0001-0.012). In the T2DM group, lower cerebral vasoreactivity was associated with a greater decrease in daily living activities score (r Type 2 diabetes mellitus (T2DM) has been recognized as an independent risk for development of cognitive impairment and dementia.1,2 Endothelial dysfunction and impaired cerebral vasoregulation associated with hyperglycemia and elevated proinflammatory cytokine levels have been linked to functional decline in T2DM.3-5 The aim of this study was to prospectively determine the associations between inflammation, cerebral vasoregulation, and cognitive performance over a 2-year span in older adults with and without T2DM. We hypothesized that (1) inflammation and hyperglycemia are associated with impaired vasoregulation in the brain, and (2) impaired vasoregulation is associated with cognitive decline in T2DM.

We report a fatal case of Rhizopus azygosporus pneumonia in a 56-year-old man hospitalized for COVID-19 who had received methylprednisolone and tocilizumab. Although COVID-associated pulmonary aspergillosis has been widely documented, mucormycosis has been rarely reported. In this patient, receipt of two commonly used immunosuppressants likely contributed to mucormycosis risk, suggesting the need for vigilance in hospitalized patients with COVID-19.

Background: Acquiring high resolution quantitative behavioural data underwater often involves installation of costly infrastructure, or capture and manipulation of animals. Aquatic movement ecology can therefore be limited in taxonomic range and ecological coverage. Methods: Here we present a novel deep-learning based, multi-individual tracking approach, which incorporates Structure-from-Motion in order to determine the 3D location, body position and the visual environment of every recorded individual. The application is based on low-cost cameras and does not require the animals to be confined, manipulated, or handled in any way. Results: Using this approach, single individuals, small heterospecific groups and schools of fish were tracked in freshwater and marine environments of varying complexity. Positional tracking errors as low as 1.09 ± 0.47 cm (RSME) in underwater areas up to 500 m 2 were recorded. Conclusions: This cost-effective and open-source framework allows the analysis of animal behaviour in aquatic systems at an unprecedented resolution. Implementing this versatile approach, quantitative behavioural analysis can be employed in a wide range of natural contexts, vastly expanding our potential for examining non-model systems and species.

Deficits in insect-mediated pollination service undermine ecosystem biodiversity and function, human nutrition, and economic welfare. Global pollinator supply continues to decline, while production of pollination-dependent crops increases. Using publicly available price and production data and existing pollination field studies, we quantify economic dependence of United States crops on insect-mediated pollination service at the county level and update existing coefficients of insect dependence of sample crops when possible. Economic value dependent on pollination service totals 34.0 billion USD in 2012. Twenty percent of US counties produce 80% of total economic value attributable to insect pollinators. We compile county-level data and consider the spatial relationship between economic value dependent on insect-mediated pollination, region-specific forage suitability, and crop-specific agricultural areas within US landscapes. We identify vulnerable, highly dependent areas where habitat for wild pollinators has been reduced. These results can help inform future efforts to conserve and bolster managed and wild pollinator populations to ensure sustainable production of key agricultural crops.

An animal that tries to remove a mark from its body that is only visible when looking into a mirror displays the capacity for mirror self-recognition (MSR), which has been interpreted as evidence for self-awareness. Conservative interpretations of existing data conclude that convincing evidence for MSR is currently restricted to great apes. Here, we address proposed shortcomings of a previous study on MSR in the cleaner wrasse Labroides dimidiatus, by varying preexposure to mirrors and by marking individuals with different colors. We found that (1) 14/14 new individuals scraped their throat when a brown mark had been provisioned, but only in the presence of a mirror; (2) blue and green color marks did not elicit scraping; (3) intentionally injecting the mark deeper beneath the skin reliably elicited spontaneous scraping in the absence of a mirror; (4) mirror-naive individuals injected with a brown mark scraped their throat with lower probability and/or lower frequency compared to mirror-experienced individuals; (5) in contrast to the mirror images, seeing another fish with the same marking did not induce throat scraping; and (6) moving the mirror to another location did not elicit renewed aggression in mirror-experienced individuals. Taken together, these results increase our confidence that cleaner fish indeed pass the mark test, although only if it is presented in ecologically relevant contexts. Therefore, we reiterate the conclusion of the previous study that either self-awareness in animals or the validity of the mirror test needs to be revised.

Task-related ΔCBF during an executive function task is related to activation in several neural networks and impairment in the ability to recruit the executive network in particular is associated with slow walking speed in older adults.