Glacier surges are opportunities to study large amplitude changes in ice velocities and accompanying links to subglacial hydrology. Although the surge phase is generally explained as a disruption in the glacier's ability to drain water from the bed, the extent and duration of this disruption remain difficult to observe. Here we present a combination of in situ and remotely sensed observations of subglacial water discharge and evacuation during the latter half of an active surge and subsequent quiescent period. Our data reveal intermittently efficient subglacial drainage prior to surge termination, showing that glacier surges can persist in the presence of channel-like subglacial drainage and that successive changes in subglacial drainage efficiency can modulate active phase ice dynamics at timescales shorter than the surge cycle. Our observations favor an explanation of fast ice flow sustained through an out-of-equilibrium drainage system and a basal water surplus rather than binary switching between states in drainage efficiency.

We use satellite image processing techniques to measure surface elevation and velocity changes on a temperate surging glacier, Sít’ Kusá, throughout its entire 2013–2021 surge cycle. We present detailed records of its dynamic changes during quiescence (2013–2019) and its surge progression (2020–2021). Throughout quiescence, we observe order-of-magnitude speedups that propagate down-glacier seasonally from the glacier's upper northern tributary, above a steep icefall, into the reservoir zone for the surging portion of the glacier. The speedups initiate in fall and gradually accelerate through winter until they peak in late spring, ~1 − 2 months after the onset of melt. Propagation distance of the speedups controls the distribution of mass accumulation in the reservoir zone prior to the surge. Furthermore, the intensity and propagation distance of each year's speedup is correlated with the positive degree day sum from the preceding melt season, suggesting that winter melt storage drives the seasonal speedups. We demonstrate that the speedups are kinematically similar to the 2020–2021 surge, differing mainly in that the surge propagates past the dynamic balance line at the lower limit of the reservoir zone, likely triggered by the exceedance of a tipping point in mass accumulation and basal enthalpy in the reservoir zone.

In this paper, a multiantenna wireless transmitter communicates with an information receiver while radiating RF energy to surrounding energy harvesters. The channel between the transceivers is known to the transmitter, but the channels between the transmitter and the energy harvesters are unknown to the transmitter. By designing its transmit covariance matrix, the transmitter fully charges the energy buffers of all energy harvesters in the shortest amount of time while maintaining the target information rate toward the receiver. At the beginning of each time slot, the transmitter determines the particular beam pattern to transmit with. Throughout the whole charging process, the transmitter does not estimate the energy harvesting channel vectors. Due to the high complexity of the system, we propose a novel deep Q-network algorithm to determine the optimal transmission strategy for complex systems. Simulation results show that deep Q-network is superior to the existing algorithms in terms of the time consumption to fulfill the wireless charging process.

This work focuses on the development of a system to control the formation of bone to complement developments that have enabled potent regeneration of bony tissue. Scaffolds were fabricated with chemically modified RNA encoding for bone morphogenetic protein-9 (cmBMP9) and capped with salicylic acid (SA)-containing polymer (SAPAE). The goal was to determine if SAPAE could inhibit the formation of bone in a pilot animal study since cmBMP9 has been demonstrated to be highly effective in regenerating bone in a rat calvarial defect model. The results indicated that cmBMP9 increased bone formation (30% increase in area covered compared to control) and that SAPAE trended toward reducing the bone formation. These results suggest SAPAE could be useful as a chemical agent in reducing unwanted bone formation in implants loaded with cmBMP9.

OBJECTIVES/SPECIFIC AIMS: Our main objectives are to study sensory encoding in the adult cortex and quantify rodents’ ability to use intracortical microstimulation to guide behavior. METHODS/STUDY POPULATION: Three rats were implanted with unilateral bipolar stimulating electrodes. The electrodes were connected to a wireless neural stimulator housed in the rat’s backpack. The rat’s swim path was tracked by a video camera above the circular pool, and stimulation parameters were updated in real-time based on distance from the platform. Stimulation was delivered as the distance from the platform increased. Stimulation amplitude was determined through behavioral threshold testing, and parameters ranged from 15–75 μA with 100-Hz pulse trains and 0.2-ms pulses. Rats were first challenged with the 4-platform task in which the submerged platform was randomized across 4 possible locations. This dissociated visual cues from the platform location, as rats had knowledge of the 4 possible locations, but had to use stimulation to guide them efficiently. Next, rats were tasked with the more challenging random-platform task. Visual cues were completely dissociated from the platform location by randomizing the platform location across the entire pool. Performance using the neuroprosthetic device was assessed by comparing trials when the device was on (stimulation trial) Versus off (no-stim trial) for the 2 tasks. RESULTS/ANTICIPATED RESULTS: 4-platform task: Rats visited less potential platform locations when the neuroprosthetic was on Versus off. Rats were also more likely to visit the correct platform location on their first swim trajectory when brain stimulation was delivered. When artificial cues were not available, rats had a greater chance of visiting the platform location from the previous trial. This indicated that rats relied on visuospatial memory without the neuroprosthetic. Random platform task: Performance was measured by taking the ratio of the rat’s actual path length to the optimal path length. When the neuroprosthetic was on, rats demonstrated superior performance through a smaller path to length ratio compared with when the device was off. The platform locations of catch trials were matched to a random subset of stimulation trials, permitting a paired sample t-test. Both rats had significantly shorter path lengths when the device was on. DISCUSSION/SIGNIFICANCE OF IMPACT: Rodents have excellent navigation skills that have been well studied. They have been shown to rely on multimodal sensory information from visual, olfactory, auditory, and idiothetic cues to navigate through their environment. The importance of these cues depends on both their environmental presence and task relevance. In the original Morris water maze experiment, rats use vision to form a visuospatial map of the platform location for allocentric navigation. Here, we have shown that sensory augmented rats can pick up on novel sensory information delivered through ICMS to efficiently find a hidden platform when visual cues are made irrelevant.Our results have implications for the design of the bi-directional sensorimotor neuroprosthetic. We have demonstrated that mammals can interpret artificial sensory information to guide behavior. Future directions include investigating sensory encoding in other primary sensory areas and downstream targets along the somatosensory neuraxis.

To determine simazine movement and dissipation in a drip-irrigated Vitis vinifera vineyard under two irrigation schedules [ grower standard (GS) and current evaporation/transpiration (CET)], field experiments were conducted in a Hanford fine sandy loam, a soil type prone to leaching. In experiment 1, simazine was surface-applied in a 1.7-m swath down the vine row, and chloride was applied as a tracer. Total recovery of simazine was < 1.0% under the irrigation emitters 51 and 57 d after simazine application in 1997 and 1999, respectively. Simazine was not detected in the soil profile from 0 to 150 cm deep, 1.0 m from the emitters. A chloride tracer moved to a soil depth of 90 cm but not deeper. In experiment 2, simazine moved 75 cm under the emitters in 7 d but did not move deeper into the soil. Under the emitter, 28% of applied simazine was found 0 to 45 cm deep and 3% was > 45 cm deep. In experiment 3, which was conducted in the absence of irrigation, total recovery of simazine was 30% when sheltered from rain and 8% when exposed to rain. Rapid dissipation and proper irrigation management were key factors preventing deep percolation of simazine in these studies.

A symptom of mild cognitive impairment (MCI) and Alzheimer’s disease(AD) is a flat learning profile. Learning slope calculation methods vary, andthe optimal method for capturing neuroanatomical changes associated with MCI andearly AD pathology is unclear. This study cross-sectionally compared fourdifferent learning slope measures from the Rey Auditory Verbal Learning Test(simple slope, regression-based slope, two-slope method, peak slope) tostructural neuroimaging markers of early AD neurodegeneration (hippocampalvolume, cortical thickness in parahippocampal gyrus, precuneus, and lateralprefrontal cortex) across the cognitive aging spectrum [normalcontrol (NC); (n=198;age=76±5), MCI (n=370;age=75±7), and AD (n=171;age=76±7)] in ADNI. Within diagnostic group,general linear models related slope methods individually to neuroimagingvariables, adjusting for age, sex, education, and APOE4 status. Among MCI,better learning performance on simple slope, regression-based slope, and lateslope (Trial 2–5) from the two-slope method related to largerparahippocampal thickness (all p-values<.01) andhippocampal volume (p<.01). Better regression-basedslope (p<.01) and late slope(p<.01) were related to larger ventrolateralprefrontal cortex in MCI. No significant associations emerged between any slopeand neuroimaging variables for NC (p-values ≥.05) orAD (p-values ≥.02). Better learning performancesrelated to larger medial temporal lobe (i.e., hippocampal volume,parahippocampal gyrus thickness) and ventrolateral prefrontal cortex in MCIonly. Regression-based and late slope were most highly correlated withneuroimaging markers and explained more variance above and beyond other commonmemory indices, such as total learning. Simple slope may offer an acceptablealternative given its ease of calculation. (JINS, 2015,21, 455–467)

Impulse-control disorders have received relatively little attention from the mental health community. An increasing awareness of the prevalence and impact of these disorders is emerging. Among impulse control disorders, problematic Internet use has been considered and examined. Prevalence estimate studies indicate that problematic Internet use is experienced across geographic locations by many individuals of diverse backgrounds. This review examines problematic Internet use from epidemiological and clinical perspectives. Clinicians should be familiar with the extent of problematic Internet use and the data regarding the efficacies and tolerabilities of available treatments.

A frequent eating pattern may alter glycaemic control and augment postprandial insulin concentrations in some individuals due to the truncation of the previous postprandial period by a subsequent meal. The present study examined glucose, insulin, C-peptide and glucose-dependent insulinotropic peptide (GIP) responses in obese individuals when meals were ingested in a high-frequency pattern (every 2 h, 6M) or in a low-frequency pattern (every 4 h, 3M) over 12 h. It also examined these postprandial responses to high-frequency, high-protein meals (6MHP). In total, thirteen obese subjects completed three 12 h study days during which they consumed 6276 kJ (1500 kcal): (1) 3M – 15 % protein and 65 % carbohydrate; (2) 6M – 15 % protein and 65 % carbohydrate; (3) 6MHP – 45 % protein and 35 % carbohydrate. Blood samples were collected every 10 min and analysed for glucose, insulin, C-peptide and GIP. Insulin total AUC (tAUC) and peak insulin concentrations (P< 0·05) were higher in the 3M condition than in the 6M condition, but there were no differences in glucose tAUC between the conditions. The 6MHP regimen (glucose: 3569 (se 83) mmol/l × min (64·3 (se 1·5) g/dl × min), insulin: 1·577 (se 0·146) pmol/l (22·7 (se 2·1) μIU/dl) for 12 h) lowered glucose and insulin excursions more so over 12 h than either the 3M regimen (glucose: 3913 (se 78) mmol/l × min (70·5 (se 1·4) g/dl × min), insulin: 2·195 (se 0·146) pmol/l × min (31·6 (se 2·1) μIU/dl × min) for 12 h) or the 6M regimen (glucose: 3902 (se 83) mmol/l × min (70·3 (se 1·5) g/dl × min), insulin: 1·861 (se 0·174) pmol/l × min (26·8 (se 2·5) μIU/dl × min) for 12 h; P< 0·01). Insulin secretion, GIP concentrations and the glucose:insulin ratio were not altered by meal frequency or composition. In obese subjects, ingestion of meals in a low-frequency pattern does not alter glucose tAUC, but increases postprandial insulin responses. The substitution of carbohydrates with protein in a frequent meal pattern results in tighter glycaemic control and reduced postprandial insulin responses.

While it is clear that self-reported racial/ethnic discrimination is related to illness, there are challenges in measuring self-reported discrimination or unfair treatment. In the present study, we evaluate the psychometric properties of a self-reported instrument across racial/ethnic groups in a population-based sample, and we test and interpret findings from applying two different widely-used approaches to asking about discrimination and unfair treatment. Even though we found that the subset of items we tested tap into a single underlying concept, we also found that different groups are more likely to report on different aspects of discrimination. Whether race is mentioned in the survey question affects both frequency and mean scores of reports of racial/ethnic discrimination. Our findings suggest caution to researchers when comparing studies that have used different approaches to measure racial/ethnic discrimination and allow us to suggest practical empirical guidelines for measuring and analyzing racial/ethnic discrimination. No less important, we have developed a self-reported measure of recent racial/ethnic discrimination that functions well in a range of different racial/ethnic groups and makes it possible to compare how racial/ethnic discrimination is associated with health disparities among multiple racial/ethnic groups.