1,054 research outputs found
University of Minnesota – Twin Cities Modifications to the Montana State University Telemetry System for Stratospheric Eclipse Ballooning
On August 21, 2017, the path of totality of a solar eclipse swept across the continental United States from Oregon to South Carolina. Our team, flying weather balloons near Grand Island, Nebraska, was able to live stream the shadow of the moon from the stratosphere to the ground. The team was able to track our balloons with high accuracy due to new payload software and hardware implemented on the still image telemetry platform developed by the Montana Space Grant. In addition, the modified system allowed the team to relay commands and receive information from individual payloads attached to our balloons, giving live telemetry and control from a new GUI-based ground station control application. Although the eclipse is now over, the system will still be a powerful and useful tool for the University of Minnesota stratospheric ballooning team. The platform could be used for any other application needing real-time, ground-based communication to various payloads on a balloon gondola
Development of a Multi-Cut Payload for use in Stratospheric Ballooning Missions
The ability to cut strings (AKA lines) during stratospheric ballooning missions has a wide variety of uses including, but not limited to, (a) flight termination (i.e. cutting payloads away from the main balloon), (b) cutting away excess lift balloon(s) to slow ascent rate (and possibly achieve float), (c) cutting away ballast weights to slow descent rate or increase ascent rate, (d) cutting away burst balloon(s) on descent to avoid parachute entanglement, and (e) cutting away payloads which are intended to return to the ground independently, for experimental purposes. We report on the development of a “multi-cut” payload box that uses an Arduino microcontroller that can control the cutting of multiple strings in arbitrary order at arbitrary points during a mission, expanding our options for stratospheric ballooning operations. For example, this device may be used during the solar eclipse of August 2017 to drop a timed-series of independently-recovered Geiger counter payloads from a stratospheric balloon stack to characterize changes to the Pfotzer maximum as the Moon’s shadow passes
Hypolocomotion, asymmetrically directed behaviors (licking, lifting, flinching, and shaking) and dynamic weight bearing (gait) changes are not measures of neuropathic pain in mice
<p>Abstract</p> <p>Background</p> <p>Spontaneous (non-evoked) pain is a major clinical symptom of neuropathic syndromes, one that is understudied in basic pain research for practical reasons and because of a lack of consensus over precisely which behaviors reflect spontaneous pain in laboratory animals. It is commonly asserted that rodents experiencing pain in a hind limb exhibit hypolocomotion and decreased rearing, engage in both reflexive and organized limb directed behaviors, and avoid supporting their body weight on the affected side. Furthermore, it is assumed that the extent of these positive or negative behaviors can be used as a dependent measure of spontaneous chronic pain severity in such animals. In the present study, we tested these assumptions via blinded, systematic observation of digital video of mice with nerve injuries (chronic constriction or spared nerve injury), and automated assessment of locomotor behavior using photocell detection and dynamic weight bearing (i.e., gait) using the CatWalk<sup>® </sup>system.</p> <p>Results</p> <p>We found no deficits in locomotor activity or rearing associated with neuropathic injury. The frequency of asymmetric (ipsilaterally directed) behaviors were too rare to be seriously considered as representing spontaneous pain, and in any case did not statistically exceed what was blindly observed on the contralateral hind paw and in control (sham operated and unoperated) mice. Changes in dynamic weight bearing, on the other hand, were robust and ipsilateral after spared nerve injury (but not chronic constriction injury). However, we observed timing, pharmacological, and genetic dissociation of mechanical allodynia and gait alterations.</p> <p>Conclusions</p> <p>We conclude that spontaneous neuropathic pain in mice cannot be assessed using any of these measures, and thus caution is warranted in making such assertions.</p
Eclipse-Ballooning 2017: The U of MN – Twin Cities Experience
The stratospheric ballooning team at the U of MN – Twin Cities started working on eclipse-ballooning in the fall of 2013, even before the Montana Space Grant announced their plan to organize a national Eclipse Ballooning Project. Our team promptly signed up to assist their effort, and have been heavily involved ever since. This presentation will discuss our eclipse-ballooning efforts and progress over the past 4 years. Our experiences include experimenting with a GoPro-based video-telemetry system (which ultimately was not as successful as Montana’s Raspberry-Pi-based system), adopting (then helping test, modify, and teach other teams to learn to use) the Montana telemetry system, practicing with up-range and down-range ground station placement, developing and testing passive anti-rotation devices and active camera-pointing devices to improve video quality, landing two eclipse-telemetry systems in Minnesota lakes one week before the eclipse (ouch!), flying five balloon stacks during the eclipse from near Grand Island, NE, and organizing/hosting AHAC 2017. We will also discuss ways in which we have already begun to use the telemetry equipment for non-eclipse balloon missions. The eclipse project has greatly expanded our HAB network and ballooning capabilities in multiple different directions, and will continue to strongly influence our stratospheric ballooning program for years to come
Springtime high surface ozone events over the western United States: Quantifying the role of stratospheric intrusions
Le FORUM, Vol. 39 No. 1
https://digitalcommons.library.umaine.edu/francoamericain_forum/1044/thumbnail.jp
Mechanisms of Class II correction induced by the crown Herbst appliance as a single-phase Class II therapy : 1 year follow-up
Background The objective of this study is to evaluate the skeletal and dentoalveolar effects of the crown Herbst appliance used alone for a single phase of therapy followed by a 1-year observation period. Methods Forty patients (mean age 13.6 ± 1.3 years) with a stable Class I occlusion 1 year following the treatment with the crown Herbst appliance were selected from a prospective sample of 180 consecutively treated Class II patients. No other appliances were used during treatment or during the follow-up period. The dentoskeletal changes were compared with a matched sample of untreated Class II subjects (mean age 13.9 ± 1.6 years). Lateral cephalograms were taken before treatment, after Herbst treatment (1 year), and after 1-year follow-up. Overcorrection was avoided intentionally. Results Treatment produced an increase in mandibular length, a decrease in ANB angle, and a restriction in the vertical growth of posterior maxilla. The maxillary molars moved backward and tipped distally. The lower incisors proclined markedly, and the upper incisors became retroclined. During the follow-up period, the changes primarily were dentoalveolar in nature, with marked rebound of the upper molars and lower incisors, resulting in some increases in overbite and overjet. Conclusions The occlusal correction of Class II malocclusion observed 1 year after the crown Herbst appliance as a single-phase therapy was achieved primary due to the dentoalveolar changes and only limited skeletal change occurred.publishersversionPeer reviewe
Regional and scale-specific effects of land use on amphibian diversity [poster]
Background/Question/Methods
Habitat loss and degradation influence amphibian distributions and are important drivers of population declines. Our previous research demonstrated that road disturbance, development and wetland area consistently influence amphibian richness across regions of the U.S. Here, we examined the relative importance of these factors in different regions and at multiple spatial scales. Understanding the scales at which habitat disturbance may be affecting amphibian distributions is important for conservation planning. Specifically, we asked: 1) Over what spatial scales do distinct landscape features affect amphibian richness? and 2) Do road types (non-rural and rural) have similar effects on amphibian richness? This is the second year of a collaborative, nationwide project involving 11 U.S. colleges integrated within undergraduate biology curricula. We summarized North American Amphibian Monitoring Program data in 13 Eastern and Central U.S states and used geographic information systems to extract landscape data for 471 survey locations. We developed models to quantify the influence of landscape variables on amphibian species richness and site occupancy across five concentric buffers ranging from 300m to 10,000m.
Results/Conclusions
Across spatial scales, development, road density and agriculture were the best predictors of amphibian richness and site occupancy by individual species. Across regions, we found that scale did not exert a large influence on how landscape features influenced amphibian richness as effects were largely comparable across buffers. However, development and percent impervious surface had stronger influence on richness at smaller spatial scales. Richness was lower at survey locations with higher densities of non-rural and rural roads, and non-rural road density had a larger negative effect at smaller scales. Within regions, landscape features driving patterns of species richness varied. The scales at which these factors were associated with richness were highly variable within regions, suggesting the scale effects may be region specific. Our project demonstrates that networks of undergraduate students can collaborate to compile and analyze large ecological data sets, while engaging students in authentic and inquiry-based learning in landscape-scale ecology
Biopolitics meets Terrapolitics: Political Ontologies and Governance in Settler-Colonial Australia
Crises persist in Australian Indigenous affairs because current policy approaches do not address the intersection of Indigenous and European political worlds. This paper responds to this challenge by providing a heuristic device for delineating Settler and Indigenous Australian political ontologies and considering their interaction. It first evokes Settler and Aboriginal ontologies as respectively biopolitical (focused through life) and terrapolitical (focused through land). These ideal types help to identify important differences that inform current governance challenges. The paper discusses the entwinement of these traditions as a story of biopolitical dominance wherein Aboriginal people are governed as an “included-exclusion” within the Australian political community. Despite the overall pattern of dominance, this same entwinement offers possibilities for exchange between biopolitics and terrapolitics, and hence for breaking the recurrent crises of Indigenous affairs
Social propinquity in rodents as measured by tube cooccupancy differs between inbred and outbred genotypes
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