8 research outputs found

    Forest structure of long-term conserved areas utilizing different strategies on a continental, glacial moraine formed island

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    Understanding patterns of forest succession can help advise management plans within New England nature preserves. This study took place on Block Island, 13 miles off the coast of Rhode Island. The island has greater than 200+ years of farming practices. After 1960, conservation groups began reforesting the island using different strategies, such as actively planting with native and exotic tree species, mowing, and preventing further development. In 2018, woody vegetation was inventoried along transects within four reforested sites. Sites were characterized as the following: actively planted with exotic and native tree species and mowed (AP-M), actively planted with exotic and native species with no mowing (AP-NM), passively managed (no planting or mowing) (NP-NM), and never deforested (F). Trees (\u3e5 cm DBH) were measured and identified within 10m of four 20m transects at each site. Saplings or shrubs (\u3c 5cm DBH, \u3e 1 m in height) were counted and identified within 5m of each transect. Tree seedlings (10 cm to 1 m in height) were counted and identified within 1m of each transect. Soil samples were taken every 20m along each transect and analyzed in a soil particle analyzer to determine soil texture. Reforestation strategy had a significant effect on adult tree basal area and diversity (p-value \u3c 0.001). AP-NM had a significantly greater basal area (38.06 m2/ha) compared to “NP-NM” (13.14 m2/ha). The greatest richness of tree species was also found at “NP-NM” (5 species) while the lowest diversity was at “AP-M”, which was represented by one species (Prunus serotina). Overall, seedlings were rarely encountered, but the greatest number of seedlings (660 individuals per ha) was found at “NP-NM”, most of which were shadbush (Amelanchier canadensis). Soil texture was found to have no significant effect upon canopy but showed trends toward increased basal area and stem density with increased sand content. In conclusion, “AP-NM” significantly increased the diversity and basal area but had no effect on seedling recruitment in the understory. This is most likely due to the overpopulation of deer on the island

    Airborne Radar for sUAS Sense and Avoid

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    A primary challenge for the safe integration of small UAS operations into the National Airspace System (NAS) is traffic deconfliction, both from manned and unmanned aircraft. The UAS Traffic Management (UTM) project being conducted at the National Aeronautics and Space Administration (NASA) considers a layered approach to separation provision, ranging from segregation of operations through airspace volumes (geofences) to autonomous sense and avoid (SAA) technologies for higher risk, densely occupied airspace. Cooperative SAA systems, such as Automatic Dependent Surveillance-Broadcast (ADS-B) and/or vehicle-to-vehicle communication systems provide significant additional risk mitigation but they fail to adequately mitigate collision risks for non-cooperative (non-transponder equipped) airborne aircraft. The RAAVIN (Radar on Autonomous Aircraft to Verify ICAROUS Navigation) flight test being conducted by NASA and the Mid-Atlantic Aviation Partnership (MAAP) was designed to investigate the applicability and performance of a prototype, commercially available sUAS radar to detect and track non-cooperative airborne traffic, both manned and unmanned. The radar selected for this research was a Frequency Modulated Continuous Wave (FMCW) radar with 120 degree azimuth and 80 degree elevation field of view operating at 24.55GHz center frequency with a 200 MHz bandwidth. The radar transmits 2 watts of power thru a Metamaterial Electronically Scanning Array antenna in horizontal polarization. When the radar is transmitting, personnel must be at least 1 meter away from the active array to limit nonionizing radiation exposure. The radar physical dimensions are 18.7cm by 12.1cm by 4.1cm and it weighs less than 820 grams making it well suited for installation on small UASs. The onboard, SAA capability, known as ICAROUS, (Independent Configurable Architecture for Reliable Operations of Unmanned Systems), developed by NASA to support sUAS operations, will provide autonomous guidance using the traffic radar tracks from the onboard radar. The RAAVIN set of studies will be conducted in three phases. The first phase included outdoor, ground-based radar evaluations performed at the Virginia Techs Kentland Farm testing range in Blacksburg, VA. The test was designed to measure how well the radar could detect and track a small UAS flying in the radars field of view. The radar was used to monitor 5 test flights consisting of outbound, inbound and crossing routes at different ranges and altitudes. The UAS flown during the ground test was the Inspire 2, a quad copter weighing less than 4250 grams (10 pounds) at maximum payload. The radar was set up to scan and track targets over its full azimuthal field of view from 0 to 40 degrees in elevation. The radar was configured to eliminate tracks generated from any targets located beyond 2000 meters from the radar and moving at velocities under 1.45 meters per second. For subsequent phases of the study the radar will be integrated with a sUAS platform to evaluate its performance in flight for SAA applications ranging from sUAS to manned GA aircraft detections and tracking. Preliminary data analysis from the first outdoor ground tests showed the radar performed well at tracking the vehicle as it flew outbound and repeatedly maintained a track out to 1000 meters (maximum 1387 meters) until the vehicle slowed to a stop to reverse direction to fly inbound. As the Inspire flew inbound tracks from beyond 800 meters, a reacquisition time delay was consistently observed between when the Inspire exceeds a speed of 1.45 meters per second and when the radar indicated an inbound target was present and maintained its track. The time delay varied between 6 seconds to over 37 seconds for the inbound flights examined, and typically resulted in about a 200 meter closure distance before the Inspire track was maintained. The radar performed well at both acquiring and tracking the vehicle as it flew crossing routes out past 400 meters across the azimuthal field of view. The radar and ICAROUS software will be integrated and flown on a BFD-1400-SE8-E UAS during the next phase of the RAAVIN project. The main goal at the conclusion of this effort is to determine if this radar technology can reliably support minimum requirements for SAA applications of sUAS. In particular, the study will measure the range of vehicle detections, lateral and vertical angular errors, false and missed/late detections, and estimated distance at closest point of approach after an avoidance maneuver is executed. This last metric is directly impacted by sensor performance and indicates its suitability for the task

    Evaluation of the Glypican 3 promoter for transcriptional targeting of hepatocellular carcinoma

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    Steel, JC ORCiD: 0000-0003-3608-7542© 2018 Macmillan Publishers Ltd., part of Springer Nature. Hepatocellular carcinoma (HCC) is a major health problem as evidenced by its increasing incidence and high morbidity and mortality rates. Most patients with HCC have underlying liver disease and dysfunction which limits the current therapeutic options. Treatments that spare the liver and destroy the HCC are needed. Targeting transcriptional differences between HCC and liver cells may provide this therapeutic window. In this study, we examine the potential of the Glypican 3 (GPC3) promoter as a targeting strategy. GPC3 is an oncofetal protein belonging to the proteoglycan family which is normally only expressed during fetal development. However, in HCC, the expression of this protein is reactivated. Here, we show that GPC3 is expressed primarily in HCC and not in normal liver lines. We show that the GPC3 promoter can be used to drive expression of significantly more luciferase and eYFP in HCC cell lines compared to normal liver cells. Further, we show that vectors containing cytosine deaminase (CD) under GPC3 promotor control induced significantly more killing of HCC cell lines after treatment with 5-FC compared to normal liver cell lines. These data suggest that transcriptionally targeted delivery of transgene in HCC cells can be achieved using the GPC3 promoter and this targeting strategy produces limited toxicity to normal liver cells

    The crustal architecture of Myanmar imaged through zircon U-Pb, Lu-Hf and O isotopes: Tectonic and metallogenic implications

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    The Tethys margin in central and eastern Asia is comprised of continental terranes separated by suture zones, some of which remain cryptic. Determining the crustal architecture, and therefore the geological history, of the Eastern Tethyan margin remains challenging. Sited in the heart of this region, Myanmar is a highly prospective but poorly explored minerals jurisdiction. A better understanding of Myanmar's mineralization can only be realized through a better understanding of its tectonic history, itself reflected in at least four major magmatic belts. The Eastern and the Main Range Provinces are associated with the Late Permian to Early Triassic closure of Palaeo-Tethys. The Mogok–Mandalay–Mergui Belt and Wuntho–Popa Arc are a response to the Eocene closure of Neo-Tethys. However, magmatic ages outside these two orogenic events are also recorded. We present new zircon U-Pb, Lu-Hf and O isotope data from magmatic rocks across Myanmar, which we append to the existing dataset to isotopically characterize Myanmar's magmatic belts. Eastern Province Permian I-type magmatism has evolved eHf (-10.9 to -6.4), whilst Main Range Province Triassic S-type magmatism also records evolved eHf (-13.5 to -8.8). The Mogok-Mandalay-Mergui Belt is here divided into the Tin Province and the Mogok Metamorphic Belt. The Tin Province hosts ca. 77–50 Ma magmatism with evolved eHf (-1.2 to -15.2), and d 18 O of 5.6–8.3‰. The Mogok Metamorphic Belt exhibits a more complex magmatic and metamorphic history, and granitoids record Jurassic, Late Cretaceous, and Eocene to Miocene phases of magmatism, all of which exhibit evolved eHf values between -4.6 and -17.6, and d 18 O between 6.3 and 9.2‰. From the Tagaung-Myitkyina Belt, we report a magmatic age of 172 Ma and eHf of 18.1 to 10.8. To accommodate the geological evidence, we propose a tectonic model for Myanmar involving a greater Sibumasu – where the documented zircon isotopic variations reflect compositional variations in magmatic source – and invoke the role of a Tengchong Block. The Baoshan Block and Greater Sibumasu were likely assembled on or before the Triassic, a former Andean margin and suture which may lie across the Northern Shan Plateau, and reflected in isotopic differences between the northern and southern parts of the Mogok Metamorphic Belt. This contiguous Sibumasu–Baoshan Block then sutured onto the Indochina margin in the Late Triassic. We propose that a Tengchong Block within Myanmar provides for a southerly termination of the Meso-Tethys suture immediately north of the Mogok area. A discrete Tengchong Block may explain a discontinuous arc of Late Triassic to Jurassic I-type magmatism in central Myanmar, representing an Andean-type margin sited above a subducting Meso-Tethys on the margin of Sibumasu. The Tengchong Block sutured onto Greater Sibumasu before the Late Cretaceous, after which subduction of Neo-Tethys drove the magmatism of the Wuntho-Popa Arc and ultimately that of the Tin Province. The metallogenic character of granite belts in Myanmar reflects the crustal architecture of the region, which is remarkable for its prolific endowment of granite-hosted Sn-W mineralization in two quite distinct granite belts related to sequential Indosinian and Himalayan orogenesis
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