4,554 research outputs found
Cost and Perceived Value in Obtaining a Bachelorâs Degree in Aviation Professional Flight: Will Collegiate Aviation Price Themselves Out of the Market with Technologically Advanced Aircraft?
Traditional academic baccalaureate degree programs have become increasingly expensive throughout the US. For collegiate aviation students, this news is even more daunting. Students obtaining a bachelor\u27s degree in aviation with a professional flight emphasis face unique challenges in today\u27s colleges and universities not typified by a majority of 4-year degree programs. Perhaps the most distinctive challenge lays in the financial arena of cost and return on investment for a bachelor\u27s degree in professional flight. This article will examine the various barriers associated with a typical bachelor\u27s degree aviation student majoring in professional flight
Intergalactic Globular Clusters
We confirm and extend our previous detection of a population of intergalactic
globular clusters in Abell 1185, and report the first discovery of an
intergalactic globular cluster in the nearby Virgo cluster of galaxies. The
numbers, colors and luminosities of these objects can place constraints on
their origin, which in turn may yield new insights to the evolution of galaxies
in dense environments.Comment: 2 pages, no figures. Talk presented at JD6, IAU General Assembly XXV,
Sydney, Australia, July 2003, to appear in Highlights of Astronomy, Vol. 1
Instrumental neutron activation analysis of postclassic and historic-period pottery from Soconusco, Chiapas, Mexico [abstract]
Abstract only availableThe study involved utilizing Instrumental Neutron Activation Analysis (INAA) at the University of Missouri Research Reactor (MURR) on 96 pottery samples from the post-classic Mayan (ca. 1000-1500 C.E.) and historic eras excavated from the Soconusco region of Southern Chiapas, Mexico. This was done in order to understand and map the long-distance trade networks of Mesoamerica via the unique chemical characteristics of pottery. The samples were irradiated according to MURR procedures and measured at specific intervals on a gamma-ray spectrometer to yield the relative concentration of elemental composition. The data obtained from the use of INAA has allowed for the creation of compositional groups according to the chemical signatures of the pottery. These groups were then compared with other compositional reference groups from throughout Mesoamerica accumulated within the MURR archives. The results indicate a complex and diverse trade relationship with post-classic pottery dominated by samples produced either locally or in the surrounding Chiapas, and historic pottery being imported across Mexico from Colonial New Spawn sites such as Puebla, Mexico City and perhaps as yet un-identified production centers. It is hoped that an increase in further comparative data will help in the locating of these additional pottery production centers. From these results, this study seeks to add greater depth to the discussion of inter-regional trade systems across Mesoamerica in both the post-classic and historic periods and enhance the conclusions drawn from those discussions
Initial Flight Test Evaluation of the F-15 ACTIVE Axisymmetric Vectoring Nozzle Performance
A full envelope database of a thrust-vectoring axisymmetric nozzle performance for the Pratt & Whitney Pitch/Yaw Balance Beam Nozzle (P/YBBN) is being developed using the F-15 Advanced Control Technology for Integrated Vehicles (ACTIVE) aircraft. At this time, flight research has been completed for steady-state pitch vector angles up to 20' at an altitude of 30,000 ft from low power settings to maximum afterburner power. The nozzle performance database includes vector forces, internal nozzle pressures, and temperatures all of which can be used for regression analysis modeling. The database was used to substantiate a set of nozzle performance data from wind tunnel testing and computational fluid dynamic analyses. Findings from initial flight research at Mach 0.9 and 1.2 are presented in this paper. The results show that vector efficiency is strongly influenced by power setting. A significant discrepancy in nozzle performance has been discovered between predicted and measured results during vectoring
Fragment screening reveals salicylic hydroxamic acid as an inhibitor of <em>Trypanosoma brucei</em> GPI GlcNAc-PI de-N-acetylase
The zinc-metalloenzyme GlcNAc-PI de-N-acetylase is essential for the biosynthesis of mature GPI anchors and has been genetically validated in the bloodstream form of Trypanosoma brucei, which causes African sleeping sickness. We screened a focused library of zinc-binding fragments and identified salicylic hydroxamic acid as a GlcNAc-PI de-N-acetylase inhibitor with high ligand efficiency. This is the first small molecule inhibitor reported for the trypanosome GPI pathway. Investigating the structure activity relationship revealed that hydroxamic acid and 2-OH are essential for potency, and that substitution is tolerated at the 4- and 5-positions
Seeing the forest for the trees:A social-ecological systems approach to managing outdoor recreation visitation in parks and protected areas
Photoelectron Spectroscopy of ClH2 - and ClD2 -: A Probe of the Cl+H2 Van Der Waals Well and Spin-Orbit Excited States
Photoelectron (PE) spectra of ClHâ2 and ClDâ2 were measured at 299 nm (4.154 eV). Photodetachment of these anions accesses the prereactive van der Waals well on the ground stateCl+H2potential energy surface, as well as the low-lying spinâorbit excited states resulting from the interaction of Cl and Cl* with H2. The PE spectra are dominated by two relatively narrow peaks corresponding to transitions to the neutral Clâ
H2 and Cl*â
H2 complexes. The energetics and widths of these features are interpreted in terms of the properties of the anion and neutral potential energy surfaces
The nature of the pandemic:Exploring the negative impacts of the COVID-19 pandemic upon recreation visitor behaviors and experiences in parks and protected areas
The COVID-19 pandemic dramatically affected parks and protected areas and overall recreation visitation across the United States. While outdoor recreation has been demonstrated to be beneficial, especially during a pandemic, the resulting increase in recreation visitation raises concerns regarding the broader influence of social, situational, ecological, and behavioral factors upon overall visitor experiences. This study investigated the extent to which recreation visitorsâ behaviors and experiences have been impacted by the COVID-19 pandemic within the White Mountain National Forest (WMNF). A modified drop-off pick-up survey method was employed to collect population-level data from WMNF visitors from June to August of 2020 (n=317), at the height of the pandemic. Results from this mixed-method study suggest social factors (e.g., crowding and conflict), situational factors (e.g., access and closures), ecological factors (e.g., vegetation damage), behavioral factors (e.g., substitution), and sociodemographic factors (e.g., gender and income) significantly influenced overall visitor decision-making and experience quality within the WMNF. For example, more than one-third of visitors indicated the pandemic had either a major or severe impact upon their WMNF recreation experience. A more nuanced investigation of qualitative data determined that the majority of pandemic-related recreation impacts revolved around the themes of social impacts, general negative recreation impacts, situational and ecological impacts, and behavioral adaptation impacts. Moreover, historically marginalized populations (e.g., low-income households and females) within the sample reported significantly higher recreation experience impacts during the pandemic. This study demonstrates the influence of the pandemic upon outdoor recreation visitor experiences and behaviors and considers outdoor recreation as a central component within the broader social-ecological systems framework. This study demonstrates the influence of the pandemic upon outdoor recreation visitor experiences and behaviors and considers resource users a central component within the broader social-ecological systems conceptual framework. MANAGEMENT IMPLICATIONS: This study found that during the peak of the COVID-19 pandemic, social, situational, ecological, behavioral, and sociodemographic factors significantly influenced overall visitor decision-making andexperience quality: · Social and general recreation impacts were most common, with approximately 56% of the sample reporting these issues. · Results suggest significant crowding and conflict impacts stemmed from interactions between in-state and out-of-state visitors, largely based upon perceived violations of pandemic protocols. · Moreover, historically marginalized populations stated unique recreation impacts during the pandemic. For instance, visitors from low-income households reported significantly less substitution options as opposed to high-income visitors. · Female visitors perceived significantly more pandemic-related conflict than male visitors. Study findings suggest visitor crowding and conflict should be prioritized by resource managers, especially amongst historically marginalized populations. Resource managers should consider adopting a broader social-ecological systems approach to parks and protected areas management, particularly during a global pandemic
From a Shorter Winter Season to More Storm Damage: New Hampshire Outdoor Recreation Providers Feel Climate Impacts Far More than Visitors
In this brief, the authors examine to what extent outdoor recreation providers and visitors in New Hampshire are impacted by annual climatic conditions representative of long-term trends, specifically, through the 2024â2028 New Hampshire Statewide Comprehensive Outdoor Recreation Plan (SCORP). For the first time, the New Hampshire SCORP included an investigation of climate-related impacts on outdoor recreation from the perspective of both visitors and providers.
The findings of the study uncovered notable disparities in how New Hampshireâs outdoor recreation providers and visitors perceive climate conditionsâ impact on outdoor recreation, particularly in the categories of âwinterâ and âextreme weather.â Understanding the perspectives of both providers and visitors is critical to outdoor recreation planning because of outdoor recreationâs contributions to the state economy and the role it plays in incentivizing people to live in New Hampshire
AMPA Receptor Phosphorylation and Synaptic Colocalization on Motor Neurons Drive Maladaptive Plasticity below Complete Spinal Cord Injury.
Clinical spinal cord injury (SCI) is accompanied by comorbid peripheral injury in 47% of patients. Human and animal modeling data have shown that painful peripheral injuries undermine long-term recovery of locomotion through unknown mechanisms. Peripheral nociceptive stimuli induce maladaptive synaptic plasticity in dorsal horn sensory systems through AMPA receptor (AMPAR) phosphorylation and trafficking to synapses. Here we test whether ventral horn motor neurons in rats demonstrate similar experience-dependent maladaptive plasticity below a complete SCI in vivo. Quantitative biochemistry demonstrated that intermittent nociceptive stimulation (INS) rapidly and selectively increases AMPAR subunit GluA1 serine 831 phosphorylation and localization to synapses in the injured spinal cord, while reducing synaptic GluA2. These changes predict motor dysfunction in the absence of cell death signaling, suggesting an opportunity for therapeutic reversal. Automated confocal time-course analysis of lumbar ventral horn motor neurons confirmed a time-dependent increase in synaptic GluA1 with concurrent decrease in synaptic GluA2. Optical fractionation of neuronal plasma membranes revealed GluA2 removal from extrasynaptic sites on motor neurons early after INS followed by removal from synapses 2 h later. As GluA2-lacking AMPARs are canonical calcium-permeable AMPARs (CP-AMPARs), their stimulus- and time-dependent insertion provides a therapeutic target for limiting calcium-dependent dynamic maladaptive plasticity after SCI. Confirming this, a selective CP-AMPAR antagonist protected against INS-induced maladaptive spinal plasticity, restoring adaptive motor responses on a sensorimotor spinal training task. These findings highlight the critical involvement of AMPARs in experience-dependent spinal cord plasticity after injury and provide a pharmacologically targetable synaptic mechanism by which early postinjury experience shapes motor plasticity
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